aperture - How are neutral density filters in compact cameras implemented?

I've read here on this very site that some compact cameras don't use aperture blades to stop down the lens and limit the amount of light hitting the sensor. Stopping down increases diffraction. Instead, these cameras use neutral density filters for this purpose.

How are these implemented? Are they dropped in the light path like drop-in filters on large telephotos, or is there a LCD panel that's activated when needed?

This question is inspired by my answer to this question.

Answer

They are simple ND filters which simply slide in an out of the optical path.

You will notice that those cameras only offer two (or four for double ND filters) apertures at any given focal length. That is because they have a fixed attenuation unlike polarizing filters.

lens - How much different are the Tamron 17-50mm f/2.8 stabilized (VC) and non-stabilized versions?

I have seen these 2 lenses being suggested by many people across the site as general purpose zooms and an upgrade to the typical 18-55mm kit lenses. The price difference seems to be around $200 (~INR 10,000) between the two. The lenses are also considerably cheaper than their Canon\Nikon counterparts.

Having using the stabilized kit lens on Canon, I appreciate the importance of IS\VC for slow shutter speeds (not just low light, but also for effects). However, quite a few reviews seem to suggest that the non-VC version seems to be better optically overall. There seem to be more quality control issues with the VC version as well.

My question is two fold:

1. How do the 2 lenses compare against each other - is the premium for the VC version worthwhile for the quality trade-off?


2. How do the 2 compare to the Canon stabilized kit lens (EF-S 18-55mm IS) in terms of optical quality - are they worthwhile upgrades? (there is a similar question for Nikon)

Answer

I have the VC version (Nikon mount). I have tested it alongside my 50mm prime and found it to be just as sharp at f/3.2. It is very slightly softer at f/2.8, but only when looking at an artificial test pattern. That's one person's opinion based on a sample of one.

I have tested other non-professional zoom lenses (Nikon and Sigma) and the Tamron is far, far sharper than any of them. Unbelievably so.

A camera shop owner I know recommended the non-VC version as being very sharp and reliable (and inexpensive). He didn't say it was worth buying the non-VC version over the VC version. He just recommended it highly as a fantastic value. He did say he'd also sold a lot of the VC version and hadn't noticed any quality control issues.

Because the lens is sharp wide open, VC isn't really vital except in low light. I would say the VC is probably not worth the premium unless you intend to shoot a lot of low-light or indoors work without flash.

Can't help with the comparison to the Canon 18-55mm. I would imagine from what I've found compared to other Nikon equivalents that the Tamron will be noticeably sharper, especially wide open. You can use it at 2.8 or 3.2, whereas the Canon probably needs to be stopped down to f/5.6 or f/8 to be at its sharpest.

dslr - Caves and 100% humidity..protection?

It looks like I may have the chance to go caving (just a tour) soon and I'd love to take my DSLR (Nikon D3100) ...however, caves are nearly 100% humidity and generally rather wet.

What kind of protection and steps do I need to take to protect my gear? If any?

Answer

Frankly, it'd be worth investing in one of those Ewa-Marine "baggies" if you're actually expecting constant wetness (they're around a hundred bucks). You can go for a stash of chammy-style wipes as well (the camera will be a lot easier to handle naked when you can), but they can only get you so far. Depending on the cave, there will be areas with almost constant dripping condensation, and it's not just water that's coming down; there is a lot of corrosive mineral content as well. It's easier to keep it out of the camera and lenses than it is to get it out after the fact. You won't need to go as far as a solid housing, but you'll probably want something studier than a sandwich bag and a UV filter (the McGuyver kit for ordinary rain).

Oh, and a general tip: there's never enough flash for what you want to do. A couple of slave units never hurt anybody.

How does Nikon measure "minimum focus distance" for Macro/Micro lenses?

This question is about Nikon SLR terminology. The answer could be different for non-SLR cameras, or for different maker.

The "minimum focusing distance" in the spec — it's measured and listed between what and the subject? Between sensor and the subject? Or between front of the lens and the subject? Or between back of the lens and the subject? At close distances and large lenses sizes, this makes big difference ...

The mystery comes from a review of the 60mm AF-S Micro Nikkor lens by Ken Rockwell. Ken is very trustful and thorough reviewer. In the "spec" section, Ken lists 18.5cm as "minimum focusing distance" (close focus)". No surprise, 18.5 cm is what appears in all published specs.

But Ken apparently owns this lens. Under title "Working distance" he pictures the Nikon and teddy bear, the subject, just several centimeters in front of the lens. He writes: "Nikon 60mm AF-S at closest focus distance... I measure only ... 48mm between the front of the lens and the subject at the closest focus distance"

Hmmm. It was 18.5 cm just several paragraphs above. Now it is 4.8 cm? Can anybody explain the discrepancy ? And answer my question at the beginning?

Answer

The answer is here, from Nikon:

Minimum Focus Distance

The minimum focus distance is the shortest distance at which a lens can focus. In the case of digital SLR cameras, the distance to the subject is measured from the focal plane mark on the camera body, not from the front of the lens.

Since the lens has a minimum focus distance of 18.5cm, and is 8.9cm long, and there's a 4.6cm flange to focal plane distance for the Nikon mount, that leaves about 5cm to spare, which is just about what Ken says (especially given that lens length is probably not measured exactly from the mounting flange on the lens).

It's also worth noting that this isn't Nikon specific — all lens minimum focus distances are specified in this way, although terminology may vary slightly. (Sony uses the same term as Nikon. Canon calls it "Closest Focusing Distance", and Pentax uses "Minimum Focusing Distance". Olympus and Panasonic are inconsistent, using "Closest Focusing Distance" in lens specifications but "minimum focusing distance" in articles.)

Canon 5d Mark III: how to switch off the silent shooting mode in the Live View mode?

The problem appeared after the multi-exposure mode was used on the camera (Mark III). At this moment only the silent shooting modes are applied in the Live View mode (i.e. I don't get the "clack clack clack" of the mirror in between shots as it was before; the menu choices (silent/regular) does not affect the shooting modes used by the camera). When the shooting via the viewfinder is applied I can choose between the silent (s) and regular shooting modes, and the camera shoots in accordance with the choosing mode. Thanks.

post processing - What sort of adjustments should be applied to bring out the colors in this photograph of the aurora?

I recently had the opportunity to photograph the Aurora Borealis and while a limited number of my photographs where quite striking with almost no adjustments, a lot of them look like the following:

In other-words, they are dark and while you can tell what it is, they are a bit too dark to really enjoy properly. What sort of adjustments, if any, can I make in Lightroom 3 to bring out the colors a bit more?

Image Information:

• Canon 40D (RAW mode)


• Tokina 11-16mm



• 16mm at f/2.8 for 20 sec

Note: Right now I have the latest version of Lightroom 3 and I've been holidng off on upgrading to Lightroom 4; however, if there are pressing reasons to upgrade I will likely do so.

Answer

Basically, you need to do some post processing on this image.

From the original, the first step I performed was to make the darkest part black and the lightest white. That alone made a sizeable diffefence since your original lightest spot was only (.37, .34, .38). In other words, you were wasting over 60% of the dynamic range.

Original:

Black and white levels to full range:

Next I applied some non-linear brightness increases. The picture below is with what my software calls a "log ratio" of 1 and a brighten value of .2.

The log ratio is a logarithmic mapping of the original assumed linear brightness values. The problem with logarithmic mapping is that there is no good thing to do with full black, since that would result in negative inifinity. One way or another, you have to specify the black offset in log space, which then gets remapped to black in the output image. My log ratio parameter does this by specifying the ratio of how much difference a small increment at the low end of the range maps to compared to the same small increment at the high end of the range. The log ratio parameter is the log₂ of that ratio. A log ratio adjustment of 1 therefore causes a curve with twice the slope at the black end as the white end. A log ratio of around 4 is more normal, which results in a 16:1 ratio of slopes between the black and white ends. I don't know if you followed all this math, but basically this is a rather mild logarithmic sloshing of the values that makes the image brighter overall while preserving black and white.

The brighten factor of .2 applies a different non-linear mapping that also preserves black and white, but effects the dark areas more and the bright areas less than the log ratio parameter does.

Anyway, here is the result:

I stopped here because I don't know what the original scene looked like, and all the amplification of small changes at the dark end was starting to cause some splotchiness. This is a great example of why you don't want to take JPG images in the camera. Since they are already limited to the same 256 values per color you are ultimately going to have in the final image, there is no way to apply different mappings without losing information. If you start with the original raw 12 or 14 bit sensor values, you have a lot more detail on the brightness scale so that there is still 1/256 changes left after doing all the corrections.

autofocus - What motor gets used if both lens and camera body have a focus motor?

If both a camera body and lens have motorized autofocus, would one be used over the other or would both work in tandem to speed the focus process along?

Answer

The lens.

There are two cases to consider, assuming a built-in focus motor in the lens:

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  The lens does not have a mechanical link for the in-camera focus motor: In this case, the camera motor cannot focus the lens at all. This is the case for the vast majority of lenses.

  
  


• 
  

  The lens has a mechanical link for the in-camera focus motor: In theory any one motor could do the job but camera makers assume the in-lens motor to be better, so they use the lens' motor. It has been requested to have a camera setting added to change this in case of a failure of the in-lens motor but no camera provides this yet AFAIK.

  
  

flash - To get a main to fill lighting 3 to 1 ratio you divide your main f/ number by 3?

I have read this information off a popular Photography site ; I am confused because I tought that for a ratio of 3:1 you need to set your main light to say: f/8 and your fill only one full stop down, f 5.6 in this case.
This is what I believe is not true:

"Simple way to set your ratios. Set your camera to the desired F/stop. Let's say F/8 in this example. Set your main light with the meter to that same f/8 setting. Divide your desired ratio (say 3:1) into that F/8 stop. (8 divided by 3 = F/2.6) Set your fill to F/2.6 and take a shot."

But f/2.6 is at least 3) stops difference from f/8, so the ratio would actually be 1 to 9 if I do what the above statement says?

equipment recommendation - Which one wide-medium lens to buy as the main lens for an outdoor wedding?

I have my first solo wedding gig coming up and I'd love recommendations for almost any lens (under $1500, preferably) to go on my 7D. My Sigma wide-angle is basically no longer usable. I have some macro lenses, a tele that goes to 300mm, an 85mm portrait lens, and plans to pick up a 35mm or 50mm (I'll have these on a second body throughout the wedding).

That being said, what are my best options for the wide-angle/mid-range main lens? The Canon 24-70 2.8 and the 24-105 4L are the most obvious choices, but I do realize they're not super wide for a cropped camera. What are other good choices for sharp photos and stunning color? The wedding is outside, so having no IS is not a huge issue. Also, it's a fairly small wedding, so I don't need a whole lot of reach. I'd prefer to stay away from Sigma and Tamron since I've had trouble with them before, but I'm open to suggestions. If you've worked with any of these lenses before or have suggestions for a good, reliable investment, I could use the help. I realize this is fairly common question area, but I've been researching and can't seem to come to any conclusions, and I need to make a purchase this week to account for the learning curve. Thanks!

film - Is it true that '80s 35mm photofilm had quality corresponding to 24 megapixels?

Is it true that '80s 35mm photofilm had quality corresponding to 24 megapixels? Somebody told me so today, and I find it surprising.

Answer

I have been using various Kodak E100 series slide films (100 ISO) in a Leica, with good optics, and the detailing that my Nikon Coolscan V gets out of these is absolutely absurd. I'd say about 20 megapixels' worth of detail, give or take - easily as good as my 16.7 mp 1Ds II anyway. Given a good exposure and focusing in the first place, of course. How this compares with 80s films I do not know. And once you go to 200, 400, 800 ISO (negative) films digital wipes the floor with them, no question about it.

lens - How to compare the speed of lenses taking transmission into account?

When comparing the speed of two lenses, you almost exclusively hear about the maximum aperture. This of course makes sense, since at a certain lighting condition, a larger aperture in general allows a faster shutter speed.

But is this really the whole story? I guess the relevant property to compare is the amount of light actually hitting the sensor when the lens is wide open. Therefore, the transmission of the lenses should be important to include in the comparison.

• How much does the transmission in today's lenses affect the overall exposure?



• Does the transmission differ much between primes, which generally have simpler structure, and zoom lenses, which are more complicated.


• How much does the massive coating of modern lenses affect the transmission measured in Ev?


• Is the transmission of lenses revealed by the manufacturers?

For example, a 35/2 prime is only a third f-stop slower than a 18-35/1.8 zoom. Can the difference in transmission make the prime "effectively faster" although it has a smaller aperture? (Of course it can theoretically, I mean practically with modern lenses.)

Answer

You can look at DxOMark's Lens Ratings, and particularly the Optical Metric Scores, which include a T stop measurement. I don't put too much stock in DxOMark's overall numbers (which don't have much practical impact for real use), but if you're interested in this particular thing, here's a way to tell.

Manufacturers do not typically give this number, so the measurements DxOMark gives are probably your best bet. Fortunately, they have measured a lot of lenses.

As you can see from the numbers, it's pretty typical for the light loss to be about a third of the stop from the nominal f number, although sometimes it's almost a full stop, and occasionally it is almost nothing — and you are right that in the latter case, it's usually prime lens designs. But not always; for example, the Sigma 18-35mm F1.8 DC HSM is measured as having a T stop of 1.8.

I think coatings can make a difference here, but that's clearly not the only factor, or the main one.

Another big factor is certainly going to be rounding, not just for precision but because a lot of camera and lens numbers are actually given as "close-enough" standardized values — see How to test actual focal length? for example. This is for a number of reasons, starting with variance in focal length with distance, overall irrelevance of being exact in real use, and almost certainly also because when more impressive numbers can be written on the box without really lying, of course they will be.

As for overall impact: sure, it can make a difference, and sometimes every bit counts, but overall, if the difference is less than a stop, it's not worth sweating over.

And of course, depth of field isn't affected.

aperture - Why is the background bigger and blurrier in one of these images?

On my EM-10 Mk2, I'm testing a Panasonic 25mm f1.8 (top image) against the 20mm f1.7 (bottom image).

I tried to make the lamp take up the same space in the frame before focusing, yet the background in the case of the 25mm is much larger and blurrier than the 20mm, which I actually prefer.

Since the aperture is nearly the same size between the lenses, is this simply a function of focal distance? Any explanation about this would be very much appreciated!

Answer

In the case of the second shot (20mm focal length), the camera was positioned closer to the lamp, thus making it appear bigger than the background.

As the camera moves further away from the subject, the distance between the subject and the background becomes smaller relative to the distance between the camera and the background, making the subject appear more and more closer to the background.

backup - How can I find duplicate photos in a very large pool of data (tens to hundreds of gigs)?

Can anyone suggests a good photo duplication detection utility that works well when I am dealing with about a 100gb of data (collected over the years)?

I would prefer something that works on Ubuntu.

Thanks in advance!

Edit: Is there a tool that will help me reorganize my collection and remove duplicates, once they have been detected?

Edit2: The hard part is figuring out what to do once I have the output consisting of thousands of duplicate files (such as the output of fdupes).

Its not obvious if I can still safely delete a directory (i.e. if a directory might contain unique files), which directories are subsets of other directories and so on. An ideal tool for this problem should be able to determine file duplication an then provide a powerful means of restructuring your files and folders. Doing a merge by hardlinking (as fslint does) does indeed free up diskspace but it does not solve the underlying problem which gave rise to the duplication to start with -- i.e. bad file/dir organization.

What options are there for inexpensive 35mm film developing and digitizing?

I have a large number of rolls of undeveloped 35mm file (over 100). What are some places I can find that will develop these for a reasonable price, and ideally digitize them for online download at the same time? So far the cheapest I have found is York Photo, who will develop the film + 1 set of prints for $4.50 (includes S&H) + $1 to digitize the photos. But I have no idea of their quality.

tips - How do I prepare best for my first wedding photography event?

I am going to shoot a wedding this weekend, and I want to do my best for my friend's big day.

• 
  

  What can I do to prepare for the day in order to minimize failures and mistakes?

  
  


• 
  

  How do I avoid missing important shots?

  
  


• 
  
  

  What backup plan should I have?

  
  

I have been shooting for 6 years or so, and I know wedding is one of the hardest thing to do. I have told my friend what I end up producing will be of no match with the work of dedicated wedding photographers, not even the ones that are about to fall out of business.

They are on a tight budget, they said some photos are still better than none, they really must minimize the cost as much as they can. I exaggerated again that my photos will be worse off than the cheapest wedding photographer you can find.

She has been a close friends for years, I want to do everything I can to help her.

Their wedding is at 12:30pm coming Sunday, I have visited the venue last Sunday at 12:30pm to check traffic condition and also the lighting.

The setup is mainly outdoor (no church), the indoor area will not have a good ceiling for bounce. Being at the middle of the day, this can mean some tricky fill flash. I have jot down a list of must-have shots. I am also asking for the seating plan and the event run-down.

Gear:

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  Canon EOS 60D , EF-S 15-85mm f/3.5-5.6 IS USM

  
  


• 
  

  Canon EOS 450D (or I can borrow a 550D), EF 50mm f/1.4

  
  


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  Speedlite 580 EXII

  
  


• 
  
  

  Speedlite 270 EXII

  
  


• 
  

  Yongnuo 460 (a cheap but powerful manual flash as backup)

  
  


• 
  

  Samsung EX-1 f/1.8 point and shoot (backup of a backup...?)

  
  

Other lenses that I have but I don't think will be useful:

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  50mm f/1.8

  
  


• 
  

  EF-S 50-250mm f/4.0-5.6 IS II

  
  


• 
  

  EF-S 18-135mm f/3.5-5.6 IS (I have the better 15-85 on 60D, should I put this on the 450D as a backup allrounder?)

  
  



• 
  

  EF-S 60mm f/2.8 Macro (should I replace 50mm f/1.4 with this for added macro? You can hardly use f/1.4 under direct sunlight if you want to have fill-flash)

  
  

I have two batteries for all cameras (60D 450D and EX1). I have like in total 64GB SD card (I am really inclined to get more, or bring a laptop for on-the-fly backup, or do both). I recently repaired my 580EXII, it has a brand new flash head so the recycle time is as good as it can be, I just need a tonne of batteries. No I don't have external power pack or battery grip for my cameras.

I have a great monopod, but a cheap tripod.

I am happy to bring everything, just putting them in the boot of my car. The carpark is on-site, walking from venue to my car is under 1 minute.

I will have my girlfriend carry the 450D and shoot details / non-portraits.

One concern that I have is fill flash, I really do not have a large surface to bounce off from. I have shot events before but they are not as dynamic/critical as a wedding.

How do I prepare for differing weather conditions?

If its sunny, fill flash is probably going to be in every single shot. If its cloudy, I probably will turn off the flash. If it rains, my 60D should be fine I have used it in slight rain before, but I really don't know their plan and if they have extendable shelters etc.

What else should I prepare for? Having no experience I want to be as prepared as I can be. Maybe I have overlooked something, maybe there is something else I can do to ensure the shooting will go smoothly. Your help is greatly appreciated!

Answer

You are right, a wedding is hard to do. But it is not impossible and we all have to start somewhere.

One of the biggest challenges is going to be staying ahead of the program and getting in the right spot at the right time. Much of wedding photography is being prepared for the "next shot", getting yourself positioned and close enough to the action, and getting whatever equipment you will need also prepared.

Gear Talk

Part of being prepared is having the right equipment ready to go. This is why you see many professionals using two camera bodies - many times one with a general purpose wide angle such as a 24-70mm f/2.8, and a general purpose telephoto such as a 70-200mm f/2.8. I know that you don't have this exact option, but since you do have two bodies at your disposal, I would certainly utilize both of them as possible. Put your 15-85mm on one body, and your 50-250mm on the other - would be one option. I would keep the 50mm f/1.4 in a belt case so it is easily accessible and you can switch to it often.

One could go so far as to say that there are a few "key" lenses that you could almost do an entire wedding with, that is how important they are to a wedding kit arsenal. One of these would certainly be the a 70-200mm f/2.8 IS. It is indispensable. Another would be a very fast prime that is in the "normal" range. I would consider something like a 50mm f/1.2 or f/1.4, as well as an 85 f/1.2. So many great shots can be taken with something like this. Anything of the bride and groom together, and any shots in low light at the reception which is typically indoors and dark. You also can use it to capture excellent shallow depth of field that is very common with portrait photography today.

It sounds like you do have an arsenal of flash units, but the question is are you comfortable using these flash units off camera? I would advise against using them during the ceremony if it is outdoors and lighting is fair, unless you are completely comfortable doing so. Trying to mess with the flash settings or exposure because of the flash while the bride is walking down the isle isn't a good idea, I'd much prefer a shot without flash that is solid. Also, even using flash at all during a ceremony is typically looked down on, at least where I live. Commonly one will use flash for the procession, then turn it off for the rest of the ceremony. I would check with the bride and groom or official at the wedding for any rules or expectations.

Why might you need a 70-200mm lens? Even on an APS-C sensor, 85mm is short for capturing things like the exchange of rings, or the first kiss. For these you really will want something in the 100-200mm range. I am afraid of the quality of your EF-S 50-250mm. The focal length is up to the task, but I'm not sure about how the IQ of this lens will be. You probably have a better idea than I do.

I added some comments about getting something with a large aperture, a pro series lens that also has f/2.8. I do believe that having a lens that is capable of very shallow depth of field is nearly a requirement to shoot a wedding. Not every wedding photographer shoots this way, but the vast majority do today. You do have a 50mm f/1.4, which will do this, so that is great. But what you are kind of missing is a longer focal length that also has this.

Obviously not a 200mm f/1.4, but something that can at least throw out the background which is probably either f/4 or faster. Since you are shooting mostly variable aperture lenses, I do not think many of them will do this, if at all. In addition, a pro series f/2.8 lens also has other HUGE advantages. The image quality is typically fantastic. You can shoot nearly wide open and still get sharp shots. You also get great color, contrast, and minimal aberrations and vignetting. I'm afraid if you shoot the 50-250 or 18-135 wide open, you may not be pleased. To get good results they will have to be stopped down, causing a greater depth of field, and less light to enter the lens.

If it happens to be a bright sunny day and you are outside the whole day, this might be less of an issue, but I would still prefer the option for creative control of depth of field. Now let me be clear, I'm not saying it is impossible to shoot a wedding with what you currently have. The fact is it will be challenging. You will be pushing the limits of your equipment in many shots. With good fast glass, you still would be pushing the limits, but more comfortably. It is just a fact of the type of photography this is. It is kind of like shooting birds, you can never have fast enough glass, AF, or a long enough length. It is very demanding. So if you are going to go out and shoot this wedding with your current kit, just be as prepared as possible, and you'll certainly learn what lenses you would like for the next time. Now onto some other topics beyond glass.

You have 64GB of memory cards. On a 60D that is about 2500 shots in RAW. Of course I would recommend shooting RAW, as it will give you the most latitude in post to rescue any blown shots. Do you need more than 2500 shots? That is hard to say. I will say that as my equipment improved shooting weddings, I shot less frames. Why? Because I was more certain that the first shot I took was successful with better equipment. Upon delivery, I think somewhere in the 500-1000 image range is very common for wedding photography in my area. The actual delivery amount depends heavily on the hours of coverage for a wedding, as well as how many photographers were shooting. I think if you took something in the 1500-1700 shot range I wouldn't be surprised, but again this depends on the hours you shoot which I am unaware of. I wouldn't be afraid to shoot away, but when you do edit them, pair them down to a reasonable amount because no bride really wants to look at 1500 images. Is it possible you could take over 2500 shots? I suppose if you have a second shooter and you are really trigger happy, but I would say it is doubtful unless the event is 14hrs long.

Addressing some of the main questions that you had, what kind of backup plan should you have? Your backup plan is the second body, the second shooter, additional memory cards, multiple flash units, etc. The only concern that I have is what if your 15-85mm fails? What if the 50mm f/1.4 fails? You really don't have replacements for either of those which is of some concern. It sounds like your 18-135mm might be this, but maybe not. It certainly cant replace something at f/1.4. You are right to be concerned about rain and weather. I'm sure you are already on top of the weather forecast, and know how the venue would sit if it were to rain. If rain is likely, I would get a plastic sleeve for your body+lens, have your assistant bring an umbrella to hold over you, etc. Then you need to think about the wedding party. Do you have a backup location inside to capture group shots of the party? If you do want to do outside shots, you either need some type of an overhang, or you would want to bring along a set of matching umbrellas for them to use. Take a look at a previous question I asked on the same topic here: How do I photograph a wedding in the rain?

You mentioned things like tripods and monopods. I personally have never had enough time to use one at a wedding beyond the staged formal shots of groups. Beyond that, I see very little purpose to using one, as you will miss shots being so immobile. I do see some people if they are in very strict churches who will setup one from the far back of the church and use them with something like a 300mm or 400mm prime. I have never done so myself.

Shot List?

Beyond gear, you will want to try to be creative with a few shots, but also get the standard wedding shots. Shot lists can be nice when starting out. But think of how you will carry this and check items off, as well as if having it in chronological order will help or not. I would make sure you get the standard ones, each couple walking down the isle, father/daughter hand off to groom, first kiss, ring exchange, announcement of bride and groom - etc. Then if you have time and can do it do things like capture the faces and reactions of guests, get the overall setting captured, details such as special flowers, etc. That is speaking just for the ceremony, obviously throughout the day many more "must have" shots come up. I would even go so far as to find some images from a photographer that you admire, print them off, and try to recreate 1 or 2 of the poses. I'm not suggesting something that would take hours of setup or a special location, but simple poses and ideas so if you run out of good ideas on the big day, you have some ready to go.

Take a look at the existing wedding tag and answers we have here on this site, you may find some value: https://photo.stackexchange.com/questions/tagged/wedding

Wrap up

Weddings are fun, fast paced, full of action, tiring, and stressful. Make sure to eat some food, drink water, and not carry too much on your back. The day gets long especially if you are doing a 10-12 hour one(but hopefully you aren't). I've never shot anything else quite like them, the pressure is on, and you are many times looked at to be a wedding coordinator when one is not around. Having a second shooter or assistant with makes a huge difference, if you can do this, I would recommend it. Be prepared to take charge to get people setup for posed shots, half of the wedding party might be drunk or crying, so you always have a challenge or two. But a quiet photographer whispering to get the group shot is never a good thing. Be as familiar with "standard" weddings as possible. What does the bride and groom do when standing in front of the cake about to cut the first piece? You will get asked!

It is too late to do it for this event, but I would suggest becoming a second shooter or assistant for other weddings if this is something you want to pursue. We have an excellent question here that covers this very very well: How do I go about becoming a second shooter for a wedding photographer?

Overall, bring as much backup equipment as you can, shot list with some ideas, rent/steal/borrow as good of glass as reasonably possible, and be in the moment. More than almost any other type of photography you have to be aware of your surroundings, the event timeline, and be on the ball! It is stressful for most people, but the results can be rewarding and profitable. Good luck!

post processing - Please suggest a workflow on Mac using only free/open source software

I own a D90 with a Nikon 50mm f/1.8 prime lens. However ever since buying my camera I am struggling to find a proper workflow to process RAW images on my Mac which does at least the following

1. Adjust shadows and highlights.


2. Adjust an image via its histogram.


3. Adjust white balance.



4. Adjust exposure.


5. Crop a photo.


6. Present a preview of how the photo may look like after printing.


7. Apply EXIF tags.


8. Apply watermarks.

So my question is what kind of workflow should I follow, if I were constrained to use only free software on my Mac?

Edit: Please also suggest a software or a set of software applications to use.

Edit: Flagged as a wiki question since there can't be correct or perfect answer.

Edit: Given the fact that a freeware will probably not be able to cut it, I have come to the conclusion that I will need to buy a low cost software for this. I am keen on using Lightroom but may have to settle with iPhoto.

Answer

Given that the reason for the question is price, I encourage you to rethink this constraint. How much is your time worth? You can get excellent post-processing software for little money compared to a lens. For example, Bibble can do everything above in the same application (might need a plugin for the watermark) and it costs only $100 for the lite version.

I tried to go the same route (on Linux) and got tired of screwing around with freeware. The commercial software is way better and your time is worth more than you think it is - particularly since the smoother post-processing is, the more fun photography will be. :)

software - How can I export reduced resolution RAW files from Lightroom?

I read that in Lightroom 4 is possible to export reduced resolution raw files.

Does anybody know how to do it?

Answer

Having done some research on the Adobe Lightroom help site I found this article on how to export to file.

http://help.adobe.com/en_US/lightroom/using/WS75C39DDC-B701-4840-A703-0755A5C04878.html

I believe the feature you are referencing to is to do with

Enhanced DNG options

• Resolution reduction via export provides the ability to share lower resolution versions of the original raw file without losing the capabilities offered by raw.

http://blogs.adobe.com/lightroomjournal/2012/01/lr4betanowavailable.html

film - Is it safe to keep my camera in the hot car?

I'd like to keep my large format camera in the car during the day at work, along with filters, adapters, tripod, etc. The car sits outside and I'm sure the temperature soars to over 120F some days inside that car. If I take the film inside with me, is it possible the camera or lenses will suffer damage in heat like that?

Please note I am not asking about operating temperature ranges, as answered in this question. I am asking about long term damage that can occur during storage, specifically in temps higher than normally occur while operating.

Answer

The cabin of most cars can get very hot during the summertime. Where I live when the ambient temperature approaches 100ºF/38ºC on a sunny day the inside of my vehicle can go as high as 160ºF/71ºC. This is due to the energy from the sun being allowed to pass through the window glass. Most of that heat is then trapped inside because the lack of airflow doesn't allow it to be dissipated.

Such heat can affect some of the most delicate parts of your camera. If it is left in direct sunlight the long term exposure to UV can also fade the exterior finish and cause some materials to become weak and brittle.

If your vehicle has a separate trunk compartment the temperature in the trunk will stay much closer to the ambient air temperature. It will also stay hidden from prying eyes that might be looking for something of value to steal. On that same 100ºF/38ºC sunny day mentioned above, the temperature in the trunk of my car doesn't get much above 105-110ºF/40-45ºC (as measured by a digital food thermometer that is accurate to within a few tenths of a degree with both ice water and boiling water). My car's white paint probably helps. Several years ago when I had a black car the trunk got hotter, but still nowhere near the cabin temperature which could go up to 180ºF/80ºC!

I've left my gear in my current trunk many times and it seems to have suffered no ill effects from either heat or cold. I've always stored it inside protective bags/backpacks/cases and allowed it to warm or cool to ambient temperatures before removing it from the case.

Keep in mind that most cameras' 'rated' temperature is an operating temperature rating. Storage temperature rating for many devices have a broader range than their operating temperatures. This is commonly seen in the IT world where many commercial grade devices have a wider storage temperature rating (when current is not flowing to a device) than operating temperature rating (when the device is powered). Also keep in mind that an operating temperature rating does not necessarily mean operating the device outside that range will cause ill effects, it just means those are the limits at which the manufacturer has chosen to test and certify their device. Manufacturers tend to be fairly conservative in this regard.

Consumer goods, including cameras, are routinely transported via shipping containers that can reach internal temperatures of 120-130ºF/50-55ºC near the top of the container during the day for weeks at a time when transported in direct sunlight on the decks of ocean going commercial ships. The same is true for large transport trucks and rail, although high value products such as consumer electronics rarely stay loaded on a container or truck more than a few days once it has crossed the ocean.

The current Canon flagship, the EOS 1D X Mark II has an operating temperature rating of 0 – 45 °C, 85% or less humidity (32 - 113ºF). Canon doesn't publicly release storage temperature ratings. Nikon recommends not storing cameras below -10ºC or above 50ºC (they rate most of their cameras to operate at 0-40ºC). At major sporting venues with artificial turf the surface temperature can reach 130ºF/55ºC on sunny days. Ditto with closely trimmed natural grass on top of a layer of sand to enhance drainage. That's the main reason you see a lot of shooters required to kneel wearing knee pads at such events. They lay their Canon and Nikon cameras and lenses on that turf routinely.

Here's a link to a copy of an operating manual published in 1969 for a large airborne reconnaissance film camera used by the U.S. Army. The section regarding Arctic conditions states the camera may be operated as cold as 0ºF/-17ºC and stored down to -65ºF/-54ºC. It also warns against moisture and condensation as being more problematic than temperature extremes.

Notice that in this blog entry featuring tips on how to deal with hot weather from Chuck Westfall, Chief Technical Advisor at Canon USA for many years, he is much more concerned about humidity and condensation as a byproduct of moving from a cool to a very hot, humid environment than he is with heat itself.

Just be sure the camera has had a chance to cool down a bit before you start using it if it has been in an extremely hot or cold environment. Also be sure to protect it from condensation during the transition period by keeping it in a bag or protective case.

lens - What are the theoretical minimum and maximum apertures?

Is there such a thing as a maximum aperture that a lens can be open to? What about a minimum aperture that it can be closed to? Do these concepts even make any sense? Is there a lens with the narrowest aperture in the world? Is there one with the widest?

Answer

An aperture could be closed which is effectively an infinitely large f-stop number since no light gets through. The fastest possible (smallest f number) is a bit harder. The speed of a lens is limited by the ratio of the entrance pupil to the focal length of the lens. The longer the focal length, the bigger the entrance pupil must be. In theory you could make one very very large, but eventually the amount of glass is going to make it so you physically would lose more light than you were gaining.

There "record" for fastest lens is arguably the f/.33 Super-Q-Gigantar 40mm, but it was really just a marketing gimmick and only one was ever made. It isn't actually functional. There is a functional f/.7 lens of which 10 were made. Six were purchased by Nasa, Carl Zeiss kept one for himself and 3 of them were purchased by Stanley Kubrick and used in the film Barry Lyndon.

In theory, it should be possible to design lenses faster than this, but the cost and benefit are simply not worth it. The lenses become too costly and complex and don't offer any significant benefit for the effort since the difficulty goes up faster than exponentially. (Since each f/stop requires a doubling of the size and physical issues make it more that twice as complicated for each additional f-stop.)

lens - What is the Nyquist Limit and what is its significance to photographers?

The Nyquist Limit is frequently mentioned in the context of lens and sensor resolution.
What is it and what is its significance to photographers?

Here is an example of it being used by DPReview.com in their resolution testing.

Answer

Please note that the following is a simplification of how things actually work

Background:

In digital photography, a light pattern is focused by the lens onto the image sensor. The image sensor is made up of millions of tiny light-sensitive sensors whose measurements are combined to form a 2-dimential array of pixels. Each tiny sensor produces a single light intensity measurement. For simplicity, I will look at the 1-dimensional case. (Think of this as a slice that looks at only a single row of pixels).

Sampling:

Our row of tiny sensors, each of which is measuring a single point of light, is performing sampling of a continuous signal (the light coming through the lens) to produce a discrete signal (light intensity values at each evenly spaced pixel).

Sampling Theorem:

The minimum sampling rate (i.e., the number of sensors per inch) that produces a signal that still contains all of the original signal’s information is known as the Nyquist rate, which is twice the maximum frequency in the original signal. The top plot in the figure below shows a 1Hz sine wave sampled at the Nyquist rate, which for this sine wave is 2Hz. The resulting discrete signal, shown in red, contains the same information as the discrete signal plotted beneath it, which was sampled at a frequency of 10Hz. While a slight over simplification, it is essentially true that no information is lost when the original sample rate is known, and the highest frequency in the original signal is less than half the sample rate.

Effects of under sampling:

If the sample frequency were less than 2 times the maximum frequency of the signal, then the signal is said to be under sampled. In that case, it is not possible to reconstruct the original continuous signal from the discrete one. An illustration of why this is the case can be found in the figure below. There, two sine waves of different frequencies sampled at the same rate produce the same set of discrete points. These two sine waves are called aliases of each other.

All discrete and digital signals have an infinite number of aliases, which correspond to all the sine waves that could produce the discrete signals. While the existence of these aliases may seem to present a problem when reconstructing the original signal, the solution is to ignore all signal content above the maximum frequency of the original signal. This is equivalent to assuming that the sampled points were taken from the lowest possible frequency sinusoid. Trouble arises when aliases overlap, which can happen when a signal is under sampled.

But Photographs Don't Look Like Sinusoidal Waves. How is all this Relevant?

The reason all of this matters for images is that through application of the Fourier Series, any signal of finite length can be represented as a sum of sinusoids. This means that even if a picture has no discernable wave pattern, it can still be represented as a sequence of sinusoids of different frequencies. The highest frequency that can be represented in the image is half the Nyquist rate (sampling frequency).

---

Meanings of Similar Terms:

Nyquist rate - The lowest possible sampling frequency that can be used while still guaranteeing the possibility of perfect reconstruction of the original continuous signal.

Nyquist frequency - The highest frequency continuous signal that can be represented by a discreet signal (for a given sampling frequency).

These two terms are two sides of the same coin. The first gives you a bound on sampling rate as a function of max frequency. The second gives you the max possible frequency as a function of sampling rate. See Wikipedia: Nyquist frequency for further reading.

Nyquist Limit is another name for Nyquist frequency. See wolfram.com: Nyquist Frequency

outdoor - Is there any app to show sun position and possibly also angle for particular times?

I was invited to shoot an particular event outdoors. Is there any tool which could help me to avoid backlight?

I searched the web and found apps like Photoephemeris, Suncalc etc. but none of them shows me sun movement during time.

I does not have to implement map - something like compass rose with time, sunset and sunrise would be enough.

Something to tell me not to put tripod with camera towards southwest from 5 to 6pm etc.

is there such a tool?

thanks

equipment recommendation - Will I miss anything if I replace my aging DSLR with a bridge camera?

This is my first question in /photography. I'm a very amateur photographer, doing things wrong and by eye with lots of trial-and-error all the time.

I currently own a reflex Nikon D70 my uncle gave us after he bought a better one. It has some nice settings, and he bought a a Nikkor 28-80mm F/3.5-5.6 zoom lens for it. It behaves nicely, but it's getting old (it has those old cartridges before SD cards existed) and every new charge takes longer than the last.

I'm planning to upgrade to a better camera, and there are some neat offers on a nearby superstore (MediaMarkt), this one catching my eye:

Sony DSC-H400 63x, Sensor Super HAD 1/2/3 CCD 20.1MP -> for less than 300€ taxes included

I don't have any type of extra information aside from that, all I can get from the official site is clinical data from other cameras that I suspect it's not 100% accurate, and there's no photography expert on the store to ask.

The common things I use my D70 for are: taking pictures of scenery (castles, towns, forests, waves hitting rocks, etc...), nearby (<5m) persons and objects, and well, things where I want to save a memory in digital format, not for professional purposes at all.

Being that my objective is to have a decent, good-zooming (superzoom looks awesome), amateur (but with manual settings) camera, is this Sony a good replacement? Will I miss any features? Is there any better, similarly-priced alternative you know of?

Basically, I want to know whether I will get better quality photos than I currently do, given the examples, with any averagely-priced bridge camera similar to that Sony, and if it's worth it.

examples of current camera results

Full zoom-out of town at night, bad quality I know; notice the pink blur at the left.

Maximum zoom on that pink blur from almost the same spot:

Daylight, cloudy, modified with Adobe Lightroom, scenery:

Same day, same beach, different settings:

Same day, same beach, rocks:

Answer

In general you will find a great deal of distaste for bridge cameras here and on most photography forums. In a few unique circumstances they can be good options (very inexpensive super zoom) but for most people they aren't recommended.

Sensor size is a big deal

Why not get a bridge camera? Since they were introduced and became somewhat popular, the market has generally moved past them for one main reason. The sensors that most bridge cameras have are tiny and not well suited to the demands of today's digital photographers. The sensor that you will find in a standard bridge camera is similar in sized to what you will find in a regular smartphone of today. In other words, beyond having a physical optical zoom and some dedicated buttons, you really aren't getting much else beyond what most people already carry in their pockets.

You are right that the Nikon D70 is showing its age. But it still has the ability for interchangeable lenses which makes it somewhat capable even compared to a bridge camera of today.

To compare, the Sony bridge camera you are looking at has an image sensor of 6.17 x 4.55 mm (1/2.3") in size. The Nikon D70 has an image sensor of 23.7 mm × 15.6 mm.

What I would recommend

If you really want better quality, but can't spend much more, you are going to be severely limited in your options. I would advise a used model that is 2-3 generations old. The D70 is 7 generations old currently so it is showing its age. If you don't feel the need to stick with a DSLR(which I don't think you necessarily need to either), I would advise looking at mirrorless camearas such as the Sony RX-100 (1st generation), which you can get in your price range and still take excellent shots with. Note that some but not all mirrorless cameras do offer much larger sensors compared to the bridge camera you are looking at, plus of course could be purchased with features of a much newer camera.

Conclusion

So, in the end; only you can determine what is the best camera for you and your budget. But be aware that you will find a largely negative impression of bridge cameras here and on similar websites when comparing these two cameras due to the sensor size.

See also:

_{Note: some people consider mirrorless cameras bridge cameras too. In my answer I am considering them separate lines.}

shooting technique - What is the best way to avoid moon and light glare in night exposures without using photo editing software

I took this photo yesterday and although I love it, I wish It didn't have as much glare from the moon or the city lights. I know I could go into lightroom and photoshop and crop a new moon in, but I don't want to do that.

I'm looking to learn the technique that when I go on the field and shoot a similar photo again will help me avoid such glares.

Answer

Are you still wanting to include the moon in the shot? If so, then think about how you control flare during the daytime and shooting into strong light sources.

• Use a hood to protect from off-axis flares that are outside of the field of view.


• Remove any non-multicoated filters from the light path as these are sources of flare.



• Stop down to improve the coma distortion from your lens.

If you don't need to include the moon as a light source, then you'll want to use a hood as you move the camera off center.

lens - What should I do to avoid switching lenses?

I'm thinking of buying a telephoto lens for my Canon 550D (3x zoom isn't very helpful), but I won't be able to do very good macro shots with it. Since I do a lot of both, I would be switching lenses quite often, which isn't too good for the camera.

My question is, what should I do if I want to take different kinds of pictures and keep my camera clean on the inside? I was hoping that there exists a lens with over 12x zoom which can also do fairly good macro shots, but I might just be wanting too much ;)

Answer

Changing lenses is the single best thing about having a DSLR, if you want 12x zoom and macro ability without ever changing lenses you want a bridge camera.

Changing lenses often isn't bad for the camera per se, I go through days when I do 10 or 20 lens changes. The wear on the mount is totally negligible. Whilst you obviously want to keep the inside of your camera clean, never changing lenses isn't the best way to go about it....

I'm afraid there is already a load of dust debris, tiny bits of plastic etc. inside the camera from when it was manufactured. The body is also not airtight even when a lens is mounted, and moving parts wear over time shedding tiny particulates that all contribute to dust.

The best way to keep it clean is to wipe the sensor with a special alcohol wipe when necessary. It's surprisingly easy (its worth noting that you're not wiping the sensor itself, but a hardened piece of glass that's stuck on the front. The need for this depends on what you're shooting - dust becomes more visible the more you stop down. I can go for months without cleaning if I'm mostly shooting in low light with wide apertures.

It's very hard for dust to irreversably ruin a photo (unlike a poor lens). It tends to only be visible against a plain background, which means it's easy to clone out in software. It's obviously better not to have the dust there, but the ability to get rid of it after a photo has been taken helps prevent me staying awake at night worrying about dust!

Why can't I get a shallow depth of field (DOF) effect?

I am trying to get a shot of the subject that is a foot or two away from the background that I would like to have show as blurry.

This is what I am going after. Notice how the face of the dog is in focus and his rump is already very blurry. dog

This is what I get at max aperture of f/1.8 with my 35mm prime lens.

Note: The items behind my daughter are about 2 feet from her. My guess is the dog's tail is about the same distance from his face and is way more blurry. What am i missing?

I thought with an aperture of f/1.8 I would get a razor thin depth of field.

EDIT: Here is an image I took inches from my daughter and the bokeh is nice at the distance the TV is. I am about 10 inches from the subject and seem to get nice bokeh at about ten feet behind her (distance from her to the tv). I would love to be able to get that same bokeh at 1 foot behind her. Is that possible and what hardware would be needed?

Answer

I think the key difference here is subject distance. Depth of field is a function of aperture, subject distance, and focal length. The closer you are to your subject, the thinner your depth of field will be. That said, longer focal length is also a way to get the effect you are looking for as well.

If you have the option, using a wider lens with a wide aperture very close to your subjects will produce that very nice, very thin DoF and produce that dreamy, creamy background blur. However, if you do not have the option of getting in real close, a longer focal length will also produce that dreamy bokeh.

You mentioned you were using a 35mm f/1.8 prime lens for the shot of your daughter. Try using a 50mm f/1.8, or even an 85mm f/1.8. Each one will successively narrow your field of view, but in doing so, they will also "compress" the background. That is, make it appear as though it is closer to the primary subject, and increase the amount of visible blur in it as well. You will want to shoot at the same distance as with the 35mm, however doing so will shrink the scope of the scene. With a 50mm, you might only capture the blue part of the ladder, and exclude that fantastically giant "rubber ducky". At 85mm, you would probably narrow the scene down to just your daughter, and maybe a little bit of the ladder.

You can, obviously, also reduce your DoF by getting closer with the 35mm, and keeping your aperture wide open. You might not get as much blur, however you would keep more of the background in the scene.

lens - Why prefer the 18-55mm and 55-250mm lenses vs 18-200mm?

There seems to be a preference for to have the

• 18 mm - 55 mm


• 55 mm - 250 mm

lenses, but no mention of why they're better than a single 18-200mm. Could someone please explain why the two separate are better than the one combined, and if anyone has quantified this difference?

(I'm curious about Canon in particular.)

studio - What are the differences between different types of cloth backdrops?

I'm considering getting backdrop for a small home portrait studio. Leaving out the issues of cloth vs. paper, I'd like to know how the different cloth options compare. There's muslin, velour (velour!), and canvas, and various natural and synthetic materials — cotton, polyester, hemp....

I assume these materials have advantages and disadvantages, but it's all confusing to me. I'm looking for something very plain to be pure black and pure white, but I'd like to understand the differences, adventages, and disadvantages of these materials in general.

What materials:

• store best,


• require least maintenance,


• come in the deepest blacks,


• and in the most-pure whites,



• resist wrinkles,


• resist dirt,


• clean easiest,


• weigh least,


• last longest,


• have the most-even, least distracting texture?


• and, of course, cost least?

How else do these cloth options differ? What other considerations are there?

Where must one make tradeoffs between features (weight and durability, say), and what things can one get together if one pays enough?

Does one generally get the same thing from different brands at the same price point, or is it important to shop around and look closely at the details?

---

I saw this general question, but I'd like to focus on the more specific here. I'll worry about size and setup separately.

Answer

You might want to keep in mind that I've been out of the pro game for a while, and that I tend to shoot people "in the wild" these days, so I'm not entirely up to date on the latest offerings. I was really hoping to see some other input here from people who have more recent experience in a professional studio environment, but here goes:

Canvas

Canvas is extremely durable, but it's not particularly portable or storable. As a painted fabric, it's well-suited for surface cleaning (wiping with a cloth or sponge); as a dyed fabric you need to allow for light colours to become somewhat dingier over time and for darks to fade -- dry cleaning, as opposed to laundering, helps, as does dark storage in a sealed bag. White isn't very white unless the canvas is painted (bleaching only gets you so far), so you need space to light the background separately if you want anything that's apparently white. (We'll take it as read that if you want "digitally white", you need to overexpose any background.)

Canvas can be fairly heavy; even the lighter grades of cotton duck sold as "canvas" are in the 10-12oz. region and painted finishes add considerably to that, so you need a sturdy support (not necessarily a certified and approved official background stand set, but a couple of thumbtacks aren't going to do it). It takes and shows wrinkles and creases, although they will relax into near invisibility over time if the canvas is dyed and unsized (and can be ironed out). Painted canvas really needs to be treated like roll paper; the binder in the paint (even if there is no visible paint film) makes creases and wrinkles very prominent. It's great stuff for swappable scenics or a durable seamless, but they really need to be kept either hung or rolled (and may take days of hanging to become usable if they were folded, even around a form, when you purchased them).

Synthetics may have changed the game a bit since I last looked; I can imagine that something other than dropcloth-grade cotton duck (which was the base fabric for all of the lighter canvasses I've worked with) might be somewhat better-behaved, but I haven't seen any evidence of them in my local pro photo emporia.

Muslin

I don't know what the kids are doing with muslin these days, but in my day it was the location alternative to mottled canvas backdrops. Not only is muslin much lighter and slightly cheaper, it takes wrinkles better. Yep, that was the point. Getting canvas to a location meant either bringing an unwieldy long roll of fabric with you, folding it neatly and having a regular pattern of creases (which look like a bad web page background image), or having a very prominent spider web of irregular creases. Canvas is a heavy fabric; it only scrunches up so much. Muslin, on the other hand, is very lightweight and glories in the ability to take an almost fractal irregular creased texture if you just sort of scrunch it up and stuff it into a bag. When that texture is combined with the soft mottling that's usually applied, it just sort of disappears. If you want a plain background, then you need to treat muslin with almost the same care as canvas.

Muslins do tend to be made from a higher grade of thread than canvasses (the source looms and threads are used for things like bed linens rather than industrial applications and grounds for painting on when they're not doing their twenty minutes a year of photographic applications). That means that the results of bleaching and dying tend to be better -- you can get a good white and intense, bright colours without painting, as well as darks with no sheen. But wrinkling and creases are always going to be a problem if you need to store or move them.

Jersey (Knits)

Jerseys tend to get around the wrinkling and creaing problem very neatly, and because of that they make great solid-colour backgrounds. Being fabrics, of course they are going to wrinkle and crease, but those wrinkles and creases can be stretched out easily. But like the man said, there ain't no such thing as a free lunch.

Jersey's don't just hang there; they pretty much need to be stretched. If you put a plain jersey background panel on a standard background stand, the top may be the advertised width, but it's going to taper down to this little six-inch wide cylinder at the bottom. You need to clamp the fabric to the uprights in oder to maintain width, and the clamps need to be frequent enough to avoid creating a visible diamond pattern due to variations in the tension. And it's pretty much a background-only material; it doesn't do well as a seamless, even if you try to stretch and weight the perimeter of the piece on the floor/table. (The stretchiness means that there's almost always a bubble popping up somewhere.) It makes a fantastic pop-up, though, and it works great on a frame -- wrinkles just vanish.

And there's the pilling problem. If you never need to clean the fabric, it can stay looking new for a very long time. If you do need to wash it, you need to remember that you're dealing with something that's really just an oversized tee shirt. Washing it by hand in cold water in the bathtub by squeezing (no agitation) and hanging to dry works well, but anything rougher than that will pretty much ruin it. If it's something that going to experience a lot of rough-and-tumble, it's the wrong fabric.

Velour/Velvet

These make great solid colours (assuming we're not talking about the "crushed" variety) and there is no substitute for black velvet as an absolute black apart from immense distance -- light goes in and it doesn't come back out. The nap hides wrinkles and creases in the base fabric very well. For lighter/brighter colours, you may need to brush the surface of the nap in order to avoid apparent colour changes (one of those large blackboard erasers that's essentially a foam rubber block with a stick inside of it and a chamois glued over one face is very quick and effective for this). Velvet/velour is great for solid whites, solid absolute blacks, and for chromakey-type colours, and a white or grey panel combined with gelled lighting can make for very smooth gradients. Velvets can be surprisingly light (although some, made as coating fabrics -- that is, fabric suitable in weight to be used for coats -- and those based on a jersey knit rather than a weave, can be surprisingly heavy).

Velvets and velours, though, are lint magnets, and the lighter colours can pick up handling grime quickly. They are absolutely not suitable for seamless applications where anything heavy (like a person or even a large tabletop subject) is involved -- raising the nap again after it has been thoroughly crushed is a bear of a job.

There's a huge range of washability -- the name really only tells you what the surface of the fabric looks like; it doesn't tell you much about the underlying construction. Some will go bald if you look at them funny, some will felt, others will laugh at your "hot" water and puny washing machines. Some will dry quickly and easily, others will absorb Lake Superior in a single gulp and be ready to use again next February if you're lucky. It's probably safe to assume that any company that depends on the goodwill of professional photographers (Lastolite, Photek, Photoflex, Westcott, and so forth) will sell you something suitable for the purpose; but as with anything else in life, I'd be wary of anything priced at the "too good to be true" level -- it may work well out of the box, but it's probably disposable.

Really, Truly White

If you are working an a small space (no real room for separately lighting the background evenly from the front) and need something that's digitally white rather than merely apparently white (that is, something that doesn't merely look white to the viewer, and can have shadows, but that will actually be all Fs when you look at the values), then it may be worth looking at backlighting. Commercially, that means using an enormous softbox or something like Lastolite's Hilite background system (which is essentially a shallow sidelit softbox). A DIY version wouldn't be too difficult to create -- the only piece that's critical is the diffusion panel, and that's really only "critical" in the sense that it needs to be seamless (one piece). The rest is just reflective fabric (that can be the cheapest silver lamé you can find at the fabric store, and can be full of seams everywhere) and a frame to hang it on (PVC, anyone?).

software - What tools do you recommend for creating HDR images?

Ideally the tool should be

1. easy to use


2. able to work with images taken without a tripod (i.e. allow to align the images)


3. free

Answer

First and foremost, the best "tool" for creating HDR images is having a proper understanding of what HDR is, and why you might need to use it. Most people are familiar with the classic "HDR Look", while at the same time not fully understanding why the classic HDR look is not necessarily how an HDR image should look.

HDR, or high dynamic range, is a means of increasing the usable, functional range of contrast and color depth in a photo. Realistically, this provides greater flexibility when working with such an image, but there should not be any fundamental differences in how the resulting image looks.

My preferred tool for working with HDR images is Photoshop. Adobe Photoshop, for several versions now, has offered a Merge to HDR tool. This tool allows you to select multiple shots of differing exposures to merge into a single 32bit, high dynamic range image. The merging process will automatically align your images and attempt to remove undesirable artifacts. (Note: Photoshop CS5 improved the HDR features, and added a deghosting capability that helps when merging hand-held shots.) Once created, you have the option of applying a tone map to the image when downconverting to 16 or 8 bit, which allows you to pick the range of tones you wish to utilize, and map them to the target color space. The final result should look like a normal photograph, just with a greater range of tones that extend beyond what you would normally be able to achieve with a single shot with the normal 5-7 stops of most digital sensor, or 5-9 stops of film or high-end digital sensors.

Another popular tool is Photomatix. This tool is explicitly designed to generate HDR images, and it has a fairly rich feature set. Photomatix is well known for creating images with that "classic HDR look", and if that is what your looking for, this is definitely the tool you want. There are some drawbacks to Photomatix, however. It sometimes has problems with generating noise, rather than eliminating it, when merging multiple shots. The end result is grainy images that have larger grains than your normal digital noise, but on par with film grain. Another quirk of Photomatix is that sometimes it caps off highlights lower than it should, limiting the available dynamic range you have to work with for bright highlights.

lens mount - Are there drawbacks when using Panasonic lenses on Olympus Micro Four Thirds cameras?

I'm interested in trying out Olympus' new OM-D E-M5, and since I'm used to using a normal prime (and just spent some time using one on Fujifilm's new mirrorless EVF camera), I'd like to try that combination.

Olympus doesn't currently offer a normal prime, though — there's a wide-angle 17mm (equivalent to the traditional 35mm focal length) and a portrait-range 45mm, both of which look nice, but there's no 25mm.

But, Panasonic offers the drool-worthy Panasonic Leica DG Summilux 25mm f/1.4 ASPH. I know Micro Four Thirds is a shared, semi-open standard — but there's compatible and then there's compatible. Even the best specifications have areas of ambiguity, and camera makers have the most incentive to test compatibility between their own products. With a modern electronic lens mount, where the lens itself has a microprocessor and its own firmware, it seems like there's a lot of potential for things to go subtly awry.

If I get this combo, will I be giving the camera a fair test, or will I find myself struggling with quirks that I wouldn't have if I stuck with Olympus lenses? Will there be any problems with focusing speed, image stabilization, or the like? (And of course, there's the flip question: if I want to use that lens, is a Panasonic camera the best place to attach it?)

Answer

I have an Olympus body (E-PL1) and a Panasonic lens (100-300mm zoom), and haven't noticed any special problems. It feels kind of silly to have 'paid' for in-lens stabilization that I keep turned off, but even when I've accidentally knocked the switch into the on position, it doesn't ruin the average shot (it makes for odd effects during long exposures on a tripod though).

composition - Can anyone suggest books/resources on the artistic side of photography?

I am a relatively new photographer. I have no problem understanding the technical side of photography (I am an engineer by trade), but I do struggle with the more 'artistic' side of photography (composition, symmetry, choice of color/B&W...)

Can anyone suggest any reading material (either online or books) that could help improve my artistic side?

Answer

One of the best books I can recommend is Michael Freeman's famous book:

This book is a rare gem, in that it does a pretty superb job of covering all the critical artistic topics of photography in a generally agnostic way. Michael Freeman is a talented photographer, and his communication of compositional aspects of photography is second to none. You may not learn everything about the artistic side of a specific kind of photography from this book, but you'll definitely learn the general basics that can be applied to most forms of photography.

Two other books by Michael Freeman should also find their way into your collection:

These three books comprise my favorites out of my entire collection, and have been the most useful (and most used) over the two or so years I've been doing photography. They do not get into the specifics of any specific field of photography, so if you are looking for detailed information information about a single field, you will have to look deeper. I generally do landscape photography, and I can offer some superb books for that field that can help you expand your artistic horizons beyond the fundamentals covered in Freeman's books. For other fields, like portraiture, architectural photography, street, etc., others can hopefully help you find what you need.

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I do landscape, nature, and wildlife photography, so most of my books are related to that area of photography. Here are some other great books that I found that have helped me learn the artistic side of things:

When it comes to other types of photography, I don't have a whole lot to offer. I've perused some books on portrait and wedding photography, however I don't own any and couldn't offer much. Architectural photography seems to be an area that is fairly lacking in books. There do seem to be some great books from individual architectural photographers that showcase their works, and observing other photographers work is a great way to learn, but it is limited. Another field I have started to delve into is astrophotography. There do seem to be a few books and resources in that area:

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Most of the books I have learned from are for landscape and wildlife/bird photography, so I am not certain how useful they will be for you. I think the compositional concepts are very sound, and apply to more than just nature photography, however.

• The Photographers Eye: Composition and Design for Better Digital Photos
  
  
  
  • Fantastic book on composition from a general perspective...definitely a must have if you need to learn more about composition
  
  
  
  
  


• Waiting for the Light
  
  
  
  • Excellent book for landscape photographers, has some good tips on composition, but mostly about natural lighting, how and when to find it, etc.
  
  
  
  


• Mastering Landscape Photography: The Luminous Landscape Essays
  
  
  
  • Another excellent book that has some great examples of composition with visual examples
  
  
  
  
  


• 100 Ways to Take Better Nature and Wildlife Photographs
  
  
  
  • Mostly wildlife, however the compositional tips are superb
  
  
  
  


• Developing Vision and Style
  
  
  
  • Not so much a book explicitly about composition, however it has a ton of example nature & landscape photographs from visionary photographers that make excellent material to review and learn from...some truly fantastic stuff. All photographs, their location, and the gear used to capture them is detailed in the back of the book. Each set of photographs from each interviewed photographer includes their sense of vision and style, which can be helpful.
  
  
  
  
  


• Working the Light: A Photography Masterclass
  
  
  
  • Good examples of quality composition, again, all landscape
  
  
  
  

technique - Is it really better to not half-press to focus with the Fujifilm X-Pro 1?

Fujifilm's new camera uses contrast-detect autofocus, and the current Internet hand-wringing is over whether this is a horrible critical flaw or not. As often happens in such discussion, a bit of street wisdom has arisen: it's better to just push the shutter the whole way. For example, this blog comment:

AF speed on the XPro isn’t that slow, the problem is that most people use it as they would an SLR/DSLR for focusing, i.e half press the shutter and wait for AF confirmation then press the shutter all the way, in most cases with the XPro and the X100 you don’t need to do this.

And there's at least one thread on DPReview, but as characteristic for such discussions, there's a lot more smoke than fire.

The X-Pro 1 manual says nothing about this, and in fact says:

S (single AF): Focus locks while the shutter button is pressed halfway. Choose for stationary subjects.

In my experience, if the subject is stationary, the half-press method works as it always does, and if it's moving the full-press method isn't as good as using AF-C (continuous autofocus). I've used plenty of point-and-shoot cameras as well, which of course use contrast-based AF, and the half-press focus lock has always served me well.

But then, a lot of people are saying this is a big deal. Is there any reasonable basis, or is it just wishful thinking?

Answer

No, it is not. There is nothing magical about not waiting at the halfway point.

What you read is silly, as if waiting would make the focus take longer or something. It does not work that way. You can press all the way as fast as you want and you'll get a shot in focus or not. The longer you wait at the half-press (in AF-S) mode or before fully pressing (in AF-C mode), the higher the probability the shot will be focused. Waiting too long might make you miss action but it won't make the camera miss focus.

Note, having an X-Pro1 one in hand and, for all I tried, I cannot see how not waiting at the half-press can improve focus.

Nikon D3100 Squeaky Lens Problems?

I've been using my Nikon D3100 and it all worked fine, until today, I tried to take a picture and pushed the button and started making a noise like the lens was working when I had it set to Manual I do everything, focus manually, zoom out/in, push the button and start hearing those noises... I removed the lens, thinking I could be the camera, but for my surprise it works fine, push the button and capture an image (bad one, since it was functioning without the lens) but it had no problem at all... Then I tried again to put it back and the same noises... Like a "squeaky" noise sort of when you try to start a car by accelerating but the engine doesn't work...

Note: It's the lens that came with the camera...

I'll appreciate any help!!!

equipment recommendation - How do I choose a polarizer?

It was suggested that I should get myself a polarizer filter to get over my reflection problem. ( How to avoid reflection when taking a picture of a ceramic object with a shiny glaze? )

I found out that a Nikon 52mm Circular Polarizing Filter CPL cost about 75 usd while I can get another filter for less than half the price — about 33 usd. (Please note that I know nothing about these filters and googled them just for the example.)

What is the difference between polarizer filters?

I need to remove the glare and nothing else — would either of the two do the magic for me? What filter do you recommend for me?

technique - Where can I see examples of great photos from cheap cameras?

I am looking for examples of really great photos made from cheap (sub-$250) point-and-shoot digital cameras. I have a group of friends who are just getting into photography, and I thought it might be helpful to steer them away from the dreaded gear obsession if I had a few examples of really nice photos taken with lesser gear.

Examples of creativity overcoming technical limitations, that sort of thing.

Especially welcome is any information about photographers who exclusively use point-and-shoot digitals.

Any ideas?

Answer

Wilson Tsoi makes some absolutely superb images with a Canon A620. This is not a P&S but a camera with manual controls which cost less than $200 USD. You need at least manual controls to get some of creativity used in those shots.

This camera has long been discontinued but today you can get the $200 USD Canon SX130 IS which has a wider and longer lens. That is the one I always recommend now for starting with photography on a budget. The next level up would be the Canon S95 or Olympus ZX-1 which cost between $400-500 USD.

developing - How long does undeveloped film last?

I received a Mamiya ZE-2 from a family member who discovered it in a closet. Along with the camera were 3 rolls of film - 2 in white plastic holders and one inside the camera.

I have no idea what may be on the film, but they seem to have been used (not developed). Would it be worth it to go develop them, will they still have the photos on them?

The 2 rolls in casings are Fujifilm Superia 400.

Answer

This depends totally on the conditions it is kept. The date on the film tends to be a conservative figure and as long as it's been kept cool it tends to last a lot longer than this. If the film is years out of date you have to make a decision if you want to risk it because you may end up with nothing.

What is the difference between in-lens image stabilizing and sensor-based image stabilizing?

And which one is more effective?

Answer

In lens stabilisation contains a servo activated rear element which acts to move the image projected by the lens in order to cancel out the camera shake.

In body stabilisation moves the sensor in order to counter camera shake.

No method is clearly better, and discussion tends to turn into a brand war as Canon and Nikon don't offer (and are not likely to offer) a body based solution, and therefore must adopt/reinforce the view than in-lens is better.

In lens stabilisation:

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  Can be tuned to the requirements of a specific lens. Telephoto lenses are likely to show a different pattern of blur (more linear, over a shorter time period) than wider angles, which have to stabilise the image for longer, where an oscillatory motion may be present.

  
  
  


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  The in-lens method stabilises what you see in the viewfinder for easier composition.

  
  


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  You can get hybrid systems that counter both angular and translational movement, which is important when the distance the subject is small. Currently the only exmaple is Canon's 100mm f/2.8L macro.

  
  


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  Works with all bodies, including film / older digital bodies, however most people have more lenses than bodies!

  
  

In body stabilisation

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  Provides stabilisation for every lens you mount, even old MF designs. Since stabilised lenses are almost always more expensive and stabilisation only exists on certain models this is a considerable plus.

  
  


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  No extra elements in the optical path to potentially flare or disperse light.

  
  


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  Can correct rotational movement and can automatically level the horizon.

  
  


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  Astronomical tracking mount like features are available on some models (such as the Pentax K-5, thanks John).

  
  

I've seen some tests that indicate the in lens stabilisation can perform better, however you do have to pay for it in every lens, see Image Stabilization Testing on SLRgear. It makes sense to me than in lens could perform slightly better as you're comparing a system designed for a specific focal length to a system that has to try and work in every situation. There's no reason in principle you couldn't have in-body stabilisation and then turn it off and use in-lens for some lenses for maximum performance.

composition - How can I get people to take an expression which fits the scene?

I have heard that there are specific indirect questions that can be used to get people to be more natural in front of a camera. Many people, who have many expressions to offer, when put in front of a camera seems to produce one or two standard "camera expressions" which they are accustomed to.

Are there any guidelines for helping models get into the feeling of the scene?

Direct transmission seems to bring anxiety. I find that the classic "hold that position" or "don't move a muscle" to be the most counterproductive statements invented. What should I say or do instead?

Answer

One trick I picked up from Zack Arias is to get the person to "move in" to the expression; you time your snap right to get the expression at the right moment.

For instance, he'll have the model close her eyes, and then have her open them. Between the time she's in the resting state of eyes-closed and the posed-looking state when she's conscious of the camera, there's a brief moment of natural expression. Get good enough with your own timing and you can capture that.

It's the motion that's the key. "Freeze" leads to conscious stiffness and anxiety, as you mention. Our brains are not used to holding body parts in still position; we're always moving.