Let's say we have two systems:
1) full-frame camera, 80 mm lens at f/2.2
2) APS-C camera, 50 mm lens at f/1.4
The subject is the same, as well as the camera position, focus distance, shutter speed and ISO. And DOF is the same too (because of 80 mm lens and f/2.2 on full-frame). And let's say that we compare two photographs from these system, resized to the same size.
Can we see the difference in the noiseness in this case?
I have a color weakness. Is there any tool or tools that I can use by using a formula or setting to correct skin color in Photoshop?
Most utilities that I found to check the actuations count haven't been updated in a long time. I also read that the actuations count isn't included in the EXIF data anymore.
So what is the best/easiest way to check the actuations count on a Canon EOS 80D? I have Lightroom and Photoshop available, but I'm willing to install another (free) utility if necessary. I use Windows, Linux is optionally available. Thank you!
Answer
From the FAQ section at Dire Studio's page for their Shutter Count application as of August 2015:
The EOS-1D X Mark II, EOS 5DS, 5DS R, 80D, 750D / Rebel T6i / Kiss X8i and 760D / Rebel T6s / 8000D cameras do not provide shutter count information. It seems that Canon has removed the shutter count functionality from the remote control interface.
If that is in fact the case then the only way to get a shutter count from the camera would be to send it to a Canon Authorized Service Center.
Dire Studio has released ShutterCount version 3 (currently for Mac or iOS only) that can now read the shutter counts for the cameras excluded above, as well as some other more recent models. From the updated FAQ page as of July 2, 2017:
Q13 - The shutter count is not displayed for new cameras (5D IV, 5DS/R, 1D X II, etc.)
Update to ShutterCount 3.0 or later on your Mac or iOS device. The Windows version will support these cameras later on.
For a list of all supported cameras, please see the Compatibility List at the ShutterCount Tech Specs page.
Dire Studio also now offers an add-on Live View Pack to their Shutter Count app that allows one to see Live View stills and Live View movie actuations of the shutters in selected cameras.
From a comment below:
Do you know how they get that information? If what they say in the initial quote is true (that the camera does not provide shutter actuation count information), how can they work around that? Or did they simply not know how to read out that information? I do not have an Apple device, I guess I'll have to wait for the updated Windows version
My understanding is that the newer models covered in version 3.0 still do not include shutter count functionality from the remote control interface. (The interface provided by the Canon Software Developers kit or SDK). Someone was either able to get code beyond the SDK from Canon or they managed to hack/reverse engineer it. Unfortunately, it doesn't look like Dire Studio is interested in ever updating the Windows version again, due to the high cost of Microsoft licensing. They once had a statement to this effect included in one of the FAQs, but it seems to no longer be there at their site.
As of 22 February, 2018 there has still been no update to the Windows version of Shutter Count. In fact, the older version compatible with Windows is no longer offered for sale by Dire Studio.
The Zone System was originally used with B&W film photography. With colour digital photography, though, couldn't you get much the same results by keeping an eye on the histogram? I think I might have missed the point, so let's ask: would I gain anything by learning to use the Zone System with my DSLR?
Answer
I'd say it's worth it. My friend Nick has written a fairly decent overview of the zone system which uses an example that was taken in colour on his digital SLR.
I have a Lowepro Slingshot 200 sling bag that I use to carry my Canon Rebel XSi with two zoom lenses. I love the bag for day trips, but it doesn't work so well for airplane trips or anytime when I need to carry the camera gear and anything else.
When I take it on the plane, there's barely enough extra space for a paperback book and an apple much less a jacket or any of the other things I might normally bring as carry on. Also, the bag is designed for easy access to the camera, but to fish out a guide book I have to unzip the entire bag.
What I'm looking for is way to transport my camera gear with enough space for and easy access to additional items like a guide book, jacket, my lunch etc. Any suggestions?
I'm interested to know if there are any limitations when shooting with a manual aperture lens in aperture priority mode, compared to shooting with a fully automatic lens.
In case this isn't clear, the lens has a ring that sets the aperture. There is no wiring to communicate aperture information to the camera, so the camera does not know what the aperture is.
Questions I have when using aperture priority mode:
Edit: while I'm interested in general about how cameras support this configuration, I need to have this information for Canon DSLRs, specifically the 60D.
Answer
Aperture priority mode works just fine with a manual lens (or no lens at all) on my Canon 550D so I assume it will work on a 60D
What happens is that the camera display shows an aperture of "F00" and the camera will set the shutter speed based on the amount of light it can see (making the result picture exactly the same as if you set the aperture in the camera).
Note that the viewfinder will be darker than with an electronic lens because it will also use the aperture you set (normally the viewfinder always uses the max aperture and the camera only stops down when you press the shutter or the DOF preview button)
My experience with this is in shooting macro pictures with an hand held reversed lens (from the point of view of the camera no lens at all) and the metering works just as well as it does with a lens attached.
So:
Can the camera calculate exposure - absolutely yes.
Does TTL flash metering work - yes, with the same rules as Av mode with a lens (shutter speed will be the same as with no flash, flash used for fill).
Can I bracket exposure - Yes (just tested it now, never tried to use bracketing with no lens before).
Always puzzle me to hear people list photography (in the context of it being art) and something different than art. Is there a reason for this historically?
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Not all photography is art, not because of some failure, but because it never meant to be that. Some documentary photography may be art, but most isn't. Some of it is just recording a moment. Most photography is decoration, or otherwise functional, not meant to be art, let alone upper-case-a Ahhrt, or Fine Art.
"What is art?" is a constant question — in fact, it's a question with no fixed answer, but a continuing conversation. See some of this in the context of photography at What makes "fine art" fine art? In fact, a useful definition may be that art is any work which participates in that conversation — it's the dialog itself which makes something art rather than any intrinsic feature of the work. Clearly, that's beside the point of much photography, which simply isn't interested in that.
But you don't have to even be concerned with this question to appreciate the craft of photography, as many people do. Art is important, but the label — or its lack — isn't necessarily a value judgment.
And of course, there's no question that there's plenty of art that isn't photography:
I probably should have made the photography circle much smaller next to all of art, but hey, this is a photography site after all. :)
Exploring the Gigapan website, I found amazing panoramas assembled from hundreds or thousands of images that include large crowds.
How does the Gigapan automated panorama device handle movements in the scene?
How well did it work in general?
Answer
Sorry guys, it's all manual masking out unwanted movement and "ghosts" shot by shot.
I took two photos - first one with Canon 5D Mark III and the second one with analog Canon EOS 500N. I used the same lens and settings (ISO/shutter/aperture) for both of them.
The company that developed my films is doing that everyday.They also scanned my analog negatives without any corrections. I noticed that the film is much more brighter than the digital image of the same scene. Left photo is scanned negative and right photo is digital.
I didn't find any answers why this happened. Could there be problems with fixing time or maybe the ISO value of the film differs from the one on the description of the film? Or is film simply brighter?
What is micro contrast, and why is it important? How is it different than regular contrast?
Matt Grum mentioned it in his answer about larger-format cameras:
There are other advantages to medium format other than image resolution... better micro contrast on account of the format size... the genuine advantages of format size in terms of sharpness and micro contrast... will always hold out.
This is the first I'd heard of the term.
Answer
Micro-contrast refers to contrast as measured between adjacent or nearly adjacent pixels. It is often perceived as sharpness.
Contrast usually refers to the contrast of the entire image which is an indicator of the captured dynamic-range.
It is possible for an image to show high micro-contrast (being very sharp) and low image contrast (being a subject with very uniform tonalities).
The converse is also possible, as any scene which exceeds the dynamic-range of a sensor will have high contrast but if shot with a poor lens or at an aperture beyond the diffraction limit it will have low micro-contrast.
I'm dorking around with a Nikon D80 and I am a total beginner. I am trying to shoot some light trails but the darn thing doesn't even take a picture. I am in manual mode with the bulb setting. For some reason, when I hold down the button, it does not take a picture. I can hold the button half way for the lens to auto focus (is that what it is doing when it is moving?), but when I press down all the way, the camera refuses to take a picture. When I go back to automatic mode, it happily takes a photo. What am I doing wrong? Thanks!!
Edited post: I am thinking it has something to do with how far/close the subject is. If there is something close, the camera doesn't want to take a picture, but if there is nothing right in front of it, it will take a pic in manual mode... (Generally hypothesizing right now.)
Answer: I think I found out what is wrong. The lens was on auto focus. I guess I had to change it to manual to use manual mode..... It works now (taking a pic of something close up that is..) Could anyone give a more detailed explanation as to what happened here? :)
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Re. your answer - you don't have to have the focus set to Manual just because you're in Manual mode, but autofocus systems generally don't work in the dark. Therefore the camera will fail to focus and refuse to take a picture. By switching to manual you remove that problem.
Switching to Auto mode may allow autofocus because it turns the AF illuminator on. Autofocus works by splitting the image coming through the lens and then calculating the focus needed to recombine it. If the image is too dark, the camera can't 'see' what it's splitting and recombining, and so it will fail to focus. The AF illuminator lights up the scene so the camera can make its decision, but it's usually turned off when in the priority or manual modes.
When light painting, it's best to pre-focus manually with the lights on, then leave it on manual and turn the lights off.
I have the Canon 600D and the "nifty fifty" 50mm f/1.8 that cost around 100$. One day when I was trying to switch lenses, I pressed on the lens release button, started twisting the 50mm, and around 1/4 of the way the lens got stuck. Now I can't pull out the lens and I'm afraid to twist it harder. I did some research and I can't find any way to fix it, so I went to the local photography shop and the offer that they gave me was $130, which is more than the cost of the lens itself!
Does anyone know how I can get this lens off without breaking it?
Answer
This may help. It's not exactly what you wanted to hear but it's probably better than what the camera shop has advised.
How to remove a stuck Canon 50mm 1.8 lens from your camera
Note that this may not be what has happened in your case, but it sounds very similar.
He says -
His fix is potentially destructive of the lens and not of the camera if care is taken. There is a possibility of saving the lens - and more so if you understand properly in advance what you are setting out to do, what is involved, why it works and what damage is likely. So read the (short) article carefully first. If you are not confident with your mechanical competence you could consider showing this 'fix' to a person who is used to fine mechanical work and ask them to try. I'd expect that a competent "watchmaker" would be likely to do this successfully.
It is also possible that, if this is what is wrong in your case, you may be able to plan an "attack" from the outside with pieces of material that allow you to attack the jamming points - perhaps mylar sheet or steel or brass shim material that you can cut "fingers from to slide into the lens-body interface. A mechanical "feeler gauge" set may provide suitable material. If trying this method, take the camera battery out first. Bearing in mind, of course, that damage to the lens is potentially acceptable but that damage to the camera is to be avoided.
If I was attempting this I'd read as many of the descriptions of the frontal attack method that I could find and look at the photos (see 'useful page' below) and THEN see if a feeler gauge attack may be able to be planned. That's just me, and you may be better advised to not even try this. If it does work it probably has more chance of actually recovering the lens than the other approaches. But, who knows what you might do to the camera in the process?
As a warning about brute force, he also notes:
Related:
The link from Inkista contains a link to this useful page of people's accounts of experiences with this lens. There are similar suggestions to those from the site above. All seem to suggest that you need to 'go in' from the lens front and I did not note any suggesting my 'feeler gauge' approach.
I have D5000 DX body and planning to buy a fast lens. I'm stuck on choosing between "AF NIKKOR 50mm f/1.4D" and "AF-S DX NIKKOR 35mm f/1.8G".
I was quite leaning towards 50mm f/1.4D, as I had plans to upgrade to FX camera body next year. But now I've lost interest in upgrading to FX body and am willing to wait for good mirrorless camera with a bigger-than-CX sensor to come from Nikon, which I think might be around two years more wait.
So my confusion now is: to get good image quality and sharpness (for portraits and closeups) with my DX body, which lens shall I choose from above two? As the picture angle is 31° 30′ at 50mm for DX body, and 44° at 35mm — but the lens construction is better in 35mm.
Also, will the aperture ring present in the 50mm be useful for macro-photography? I do have a cheap extension tubes, which I read somewhere that I would not be able to use if I buy the 35mm.
my main concern is image quality and sharpness than utilizing the extension tubes..(AUTO FOCUS AF-S is not a concern for me i guess, although some say manual focus is hard in 50mm lens) .... any Help appreciated. Thank you.
I'm looking at upgrading my kit for a music photojournalism internship over the summer and I was wondering what the best way to spend $600 was.
My current setup is a d7000, a kit lens, a manual focus 1.4/50mm and a speedlight. I'm looking at the 1.4/50mm AF, but I figure my money could be better spent, and I've gotten used to manual focus: http://minus.com/mW9z07wnQ#1
I'll be shooting small, dark 1,500-person venues -- so a 2.8/80-200mm is out of the question.
Ideas? Maybe get a diffuser for my speedlight? A fast 35mm? I've been looking at that Nikon prime fish-eye, but I'm skeptical about its use in photojournalism... Ken Rockwell recommends the Hemi plugin -- any thoughts?
Thanks for the help!
I was wondering if someone can help me out in finding which speedlites I can use on a Canon 4000D, as this camera does not have a centre connection on it.
I see pictures of the moon that looks like it is very close to the earth; I am wondering whether they are real or is there a trick to show the moon that big?
Here is an example: http://www.spaceweather.com/swpod2011/20mar11/Paco-Bellido1.jpg
Answer
Those are done using the compression of a telephoto lens. Longer lenses will magnify the subject, so will make the moon look bigger. It will also make buildings and other objects bigger, but by moving yourself further away from those earthbound objects you can reduce them back to a smaller size. But you can't really get further away from the moon, so it will remain the same size no matter where you move locally.
So in your example, that might look like it was taken from a short distance away with a 50mm lens, but in fact it may have been taken much further away with a 500mm lens. Result is the foreground looks about the same as if you'd taken it closer with a 50mm lens, but the moon on the other hand is magnified quite a bit.
Which image compression is better, LZW or ZIP? I am using Lightroom to export images.
Answer
Better is a relative term and, to some degree, will vary in terms of amount between the two depending on a variety of factors including the bit-depth, frequency of discrete colours, etc. Some experimentation may be necessary on this front, though my reading indicates LZW is good for lower bit-depth images with lots of the same colours and tones in it and ZIP for when that is not the case. In other words, if the image is 8 bits go LZW and if it is 16 bits go with ZIP, as a rule of thumb, but with the caveat that it's not an absolute rule and there may be exceptions.
The only other thing I'd note is that LZW has been in the TIFF standard since 1992 and ZIP since 2002 (as part of a supplement when Adobe added it). While that's probably more than enough time for it to no longer be an issue, there may be the odd piece of software out there that handles LZW compression but not ZIP.
This may well be a question to which the answer is "can't be done," but I was wondering whether it was possible to convert a film SLR to a DSLR by putting a sensor in place of the film. I have a bunch of old bodies and lenses which I would love to be able to use, but I just don't want to mess around with film, so I was wondering whether it's possible to convert them to take digital images.
Answer
This has certainly been done with medium format SLRs that have interchangeable backs (e.g., Leaf and Phase One backs).
For a 35mm camera, the situation isn't nearly so positive. There was once a company that claimed to be working on a digital sensor that would be shaped like a 35mm film cannister with the sensor sticking out roughly like the film tongue. I'm reasonably certain they never produced even a partially working prototype, and even more certain they never put a product onto the market. Personally, I rather doubt it could be done.
In any case, the market opportunity for such a product is mostly past -- the vast majority of people who want to shoot digital have given up on the idea and bought digital bodies. Most have upgraded at least once by now, so used digital bodies are fairly common and quite reasonably priced...
I've been trying to take some long exposure shots at night with my Canon 450D. The problem I'm having is that I can't seem to get a shot in focus. The low light conditions prevent AF from working at all, nor is there enough light for me to get the focus correct by hand. I've tried through the viewfinder and the LCD, but they're both so dark I can't tell if I'm in focus or not.
Perhaps this is a lens issue? I have the 18-55mm ƒ/3.5 kit lens and the 50mm ƒ/1.8 EF lens; neither of them have focus markings, so I'm not sure if I'm hitting ∞ or if my lenses are even capable.
Thank you very much for the suggestions. I’m not able to shine a light, as I’m hoping to get landscapes and night sky shots, and I don’t have anything powerful enough to reflect back. I tried focusing with the 50mm ƒ/1.8 wide open, but I couldn't see anything. I don't think lens speed is going to make a difference.
It sounds like trial and error is my best shot here, which is unfortunate.
Side note: It sucks that the 450D has no way to display the focal length. This info is recorded in the image metadata, so it would seem like it should be available.
I have two more options that I came up with:
Set up during the evening, when there is enough light to focus, then take the shot at night. Potentially impractical due to time, but I see no reason it wouldn’t work.
Use another camera. I tried again with my PowerShot S90, and got significantly better results. I was able to manually set the focus to infinity, and the wider angle / smaller sensor meant that I didn't have to worry as much about depth of field causing blur. While the S90 only allows for 15s exposures, CHDK removes that limitation.
Answer
Lots of good advice and things try here, but whilst faster lenses are generally good for night shots, you will get a limited improvement in AF performance so you will hit the point where it's too dark to AF.
Faster lenses will also give you a brighter viewfinder which enables better manual focus, but again up to a point, with the default focus screen you see no improvement past f/2.6
Lighting the subject to focus is a good idea but not always possible, using the depth scale isn't possible in your case so I'm going to suggest something that's not been mentioned so far.
Just as exposure bracketing uses multiple exposures to overcome metering problems, focus bracketing uses multiple shots to overcome AF problems. Start with your best guess for the focus and shoot two shots either side by moving the focus ring slightly and then examine the shots on the LCD. It's time consuming to work this way for sure, but it's a good technique to employ as a last resort. I only wish camera bodies included this as a feature as it would become faster and more accurate.
If this still doesn't work for you consider recomposing to increase your depth of field to give yourself a better chance!
I had a Canon EOS 600D for 6 years but switched now to a Canon EOS 5D Mark II because I faced the limit of my camera. I do a lot of HDR photography and felt kind of limited after all these years.
I got a really good price for a used Canon EOS 5D Mark II, and I tried it out a couple of times. The more and more I dive into the camera and it's settings I am pretty happy but the image quality is not really much better. Yes, the comparison is not fair, because the 5D Mark has a bigger FOV and therefore I had to scale the image down a little bit, still wondering if you have some tips.
Both pictures were shot with a Canon EOS 50mm, f1.8 and the following settings:
ISO 400, f1.8 and ISO 160 (left) and 125 (right). Is it just me or why did I expect a better quality? Thanks a lot for any input!
Answer
You expected it to be better because people tend to think, bigger = better. People talk about how great full frame is without understanding what is really different, and your expectations are too great.
Full-frame sensors have larger sensels than crop sensors that produce the same number of megapixels. For sensors of the same generation, full-frame sensors are expected to have an advantage in ISO sensitivity and noise. However:
The advantage is reduced on full-frame sensors that use smaller sensels to produce more megapixels.
The advantage applies primarily to high-ISO. Noise is minimized at low-ISO, such as those you used to take your test shots.
Sensible lens choices, with faster apertures, reduce the need to push ISO.
Newer technologies increase light sensitivity and reduce noise. However, Canon tends to develop technologies slower than molasses, and the EOS 5D mk2 was current throughout the 600D life-cycle. (This is why Sony has a 5-year head start on full-frame mirrorless.)
To see the noise difference between crop and full-frame, you need to take multiple ISO-matched images throughout the ISO range. View them at 100% without resizing. You should see noise become unacceptable at lower ISO settings on the crop sensor vs the full frame.
What your test images demonstrate is, when taking photographs from the same position, with the same lens, with the same settings, everything is the same between crop sensor and full frame, except field of view. Changing sensor size just changes the portion of the (exact same) imaging circle that is recorded.
What creates the "full frame look" is what people do to compensate for the different field of view. To fill the frame with the subject on a full-frame sensor, the camera has to be closer or the lens has to have a longer focal length. The difference can be reduced on crop sensors by using faster apertures, when available.
So I'm looking at the wikipedia article on Aperture, and I'm a bit confused. I understand aperture to be the diameter of the hole that lets light in. In the article, someone states that
The amount of light captured by a lens is proportional to the area of the aperture, equal to:
Area = pi ( focal length /(2 * f number) )^2
But in the f number article, they define f number as
f = focal length / aperture
It then seems trivial to substitute in:
Area = pi ( focal length / (2 * focal length / aperture) )^2
Area = pi ( focal length * aperture / (2 * focal length) )^2
Area = pi ( aperture / 2)^2
Area = pi ( radius )^2
So, my question is: Why did they bother putting something so blatantly obvious into the article? Didn't we already know that the area of the aperture was pi * r^2? Is this just me reading too much into a wikipedia article?
Answer
The focal length and f-number are photographically relevant quantities, so the formula is expressed in terms of those convenient variables. Photographers don't generally know the radius of their lens aperture for every f-stop.
I have a Nikon D7000 and I see there are a couple remote release options from Nikon: the (wired) MC-DC2 and the (wireless) ML-L3 which is also about 40% cheaper than the wired remote.
Are there any good reasons one would choose the wired remote instead of the wireless, especially given the price difference?
Answer
Infrared triggers can lose their minds when in the presence of sunlight or a strong IR source. The sun puts out SO much IR the receiver can't see the signal unless its window is in shade or very close to the transmitter. They do work really well indoors or at night though, and cost less than the radio triggers.
And, just as a FYI, a toilet-paper tube taped over the window can help the receiver pick up the transmitter's IR burst when there is a lot of IR noise as it helps the receiver's "eye" see the right IR source.
For that matter though, even PocketWizards can get confused when in the presence of lots of radio noise or certain transmitters. I had a shoot where I had receivers on both sides of me lock-up multiple times. I'd used them in the same location several times before with no problems, and the only difference was the announcer was using a wireless microphone. I'd have loved to have wired up sync lines and turned off the wireless that night.
Is there a way to find out if a picture (once taken) was taken in Manual vs. Auto mode? My daughter is in a photography class and we both have taken images with the same camera. I sometimes put it back into auto mode and she isn't sure about a few of the photos now.
Her instructor says they have to be turned in only in Manual mode, so is there a way that I can determine which images were captured in Manual mode?
I want to connect a camera to PC and take photos.
What cameras have this option? Most cameras, when connected to PC, seem to disable capturing when showing card storage?
Is there any software that can be used with any camera?
I was going through different models of Canon and found that the price range of the camera body for entry level DSLR is lesser than the semi-professional DSLR although both of these range of cameras offer the same specification, same pixel count etc.
I'm looking at the Sigma 20mm F1.8 EX DG ASP RF lens right now to use on a 35mm film Camera (Nikon N80).
The DG stands for "Digital Full Frame" according to Sigma, but they don't say what the "digital" really means. (Related, when you look at the Nikon website they say "View all D-SLR Lenses" with no indication of Film)
Does the "Digital" really mean anything if it's a Full Frame lens (as opposed to a Crop or m43), or is this just marketing talk to make people buy new lenses with their digital cameras?
Answer
Yes, lenses designed for digital sensors have several differences from their older film based camera lens counterparts. One of the primary differences is that digital sensors are more reflective than film, so anti-reflective coatings are applied to the rear element of a digital lens. This helps prevent reflections off the sensor that could result in image ghosting.
Additionally, digital sensors require light to travel down a narrow tube produced by the stack of filters (color, AA, etc) that lie directly in front of the actual photosites that convert the light energy hitting the sensor in to an electronic signal. This alters the way that the light needs to be directed to the sensor (it needs to come in from more straight on) and digital lenses may be designed to handle this better.
Finally, as Michael Clark pointed out, film didn't generally lie perfectly flat, while digital sensors do, so there is more emphasis on extreme levels of sharp resolving power on good digital lenses than film cared about.
It isn't generally a problem to use an old film lens as long as it is compatible with your camera mount system, but it is good to understand the caveats that they can have ghosting problems when shooting in to light, they often have lower sharpness and may have additional chromatic aberrations. They also tend to be older, so they may lack some of the more recent advantages in terms of focus motors and control.
My general recommendation if you are buying new and can afford it, then buy a modern lens, but if you need the capabilities of an expensive lens (such as a fast lens) cheaply, then it may be worth picking up an old film lens and working around the limitations, just make sure to research the particular lens you are looking at and how it compares to other lenses of both similar prices and similar aperture and focal length.
I'm using a Nikon D5200, which features extra ISO values between powers of two, that the Nikon D60 did not offer.
(I'm a seasoned StackExchange user and reasonably advanced amateur photographer. To avoid any misunderstanding one might want to see my profile).
As already documented, most of the time the difference between a photograph taken at e.g. ISO 200 and another at ISO 400, all other things being equal, is that an analog amplification gain is applied at the analog-to-digital conversion step. Sources: NX101 -- Capture NX - Understanding Nikon's NEF and How is ISO implemented in digital cameras?
Recently a friend told me that only power-of-two ISOs are actually implemented with the analog gain, and that other values (like 250, 320) are actually digital post-processing and thus less interesting form a noise and dynamic range point-of-view. For example "shooting at 640 loses some information". There's a similar claim in learning - What is something you learned recently about your gear that you wish you discovered earlier?. It reads:
E.g. In-between stops (640 ISO for example) is a software push above ISO 400.
If ISO 640 was a software push above ISO 400, it would mean that ISO 640 does not gain any noise advantage over ISO 400, only possibly (depending on scene) losing by post-processing some highlights that would have been available at ISO 400. Or what else?
It could also be a software reduce from ISO 800, just like ISO 50 in Nikon D800 and D800E was a software reduce from ISO100, couldn't it ? (source: 24 Things You Need to Know About the New Nikon D810).
In that latter case, the noise at ISO 640 would be as good as in ISO 800 (all things being equal, better than ISO 400 as explained on What is "ISO" on a digital camera?) but reduction could just (depending on scene) not reach as much highlights as an actual ISO 800 (analog clipping). Or what else ?
Perhaps the actual processing is only "hinting" the post-processing (base curve, dynamic lighting and the like), producing a picture that actually has the overall exposure requested at 1/3-stop granularity, without actual hard loss. In that case, the RAWs actual exposure might jump only by power-of-two ISOs and not 1/3 steps. Such hypotheses could be corroborated by taking RAWs and JPEGs at all ISOs and see how they behave.
Or perhaps this is all nitpicking?
I went to shoot a long exposure shot with my Nikon D70s. I had it set on bulb mode with an aperture of f/8. Yet when I go back to see the picture, it is simply all white. What did I do wrong, or what can I do to fix it?
I have a Nikon D300S and have been taking pictures of my son's soccer team since they were 10. Well, this past fall I was really having a hard time with capturing decent pictures, was using a 70-300 4.5, but my fantabulous soccer families presented me with a new Tamron 70-200 2.8 lens, so I am trying to play with settings. I tried taking shots of indoor soccer last night, and well, I wasn't very happy with them. I am going to a gymnastics competition (which I have never been to nor taken pictures of) to do more testing. I know two different events and picture taking scenarios, but at least it gives me a little more time to play. But any advice I could receive, I would greatly appreciate it.
The camera I was unhappy with was the D300S with a 55-300 4.5-5.6. As it became darker, the pictures would be very grainy during the game. When I took OK pictures for the senior banners, when the graphic artist enlarged the pictures, we noticed crosses all over the pictures. These were taken outside - the graphic artist indicated he had never seen something like it. As far as settings for games, I created a bank with the settings from this post:
http://johnfriend.blogspot.com/2009/10/nikon-d300-auto-focus-for-sports-i.html?m=1
When my son and his teammates were 10, I had a Coolpix, and obviously as they got older, I used a different camera. I am stuck thinking there may be an issue with the D300S (i.e. the cross in the picture) and debating if I should get a different camera, or of course user error. This fall is the only time I have had issues with the grainy pictures, or the crosses, or even some pictures appearing pixelated.
Is there any way to set Apple Aperture to always keep all files stored in an external location, without having to go through the extra step of manually moving files to the location beforehand myself and then explicitly directing Aperture to only reference the files?
I'm not sure there's really such a thing as a "managed library" and a "referenced library", more like "managed images" and "referenced images". This is unfortunate because I want to
For example, not command-dragging files to Aperture, but just having it know to always import by reference. And furthermore, any photos added should be moved automatically to the predefined library location, for example an external hard drive and folders organized by date.
As another example, consider Photostream: I would like Photostream images to always be downloaded into a pre-defined referenced folder as described. I haven't tested this - where are Photostream photos store in a "referenced" library? I am assuming always within the library as "managed" images.
Basically, I just want Aperture to keep all its image files in an external location but manage them as if they were inside the library bundle.
An autofocus system is system based on a feedback loop, where the AF sensor error reading if fed back to the lens focus motor. Being a closed loop, then theoretically there should be no focusing errors (at least when lighting is good enough).
So I was wondering, what is the source for this kind of error that requires MFA different for each lens?
The one reason I could think of is that the AF sensor is not perfectly aligned with the image sensor - a thing that will create a constant misfocus. But then, this probably needs to be constant for all lenses.
Whet exactly is being calibrated with MFA? Is is it the AF sensor position, the image sensor, control loop gain, etc.?
Answer
Your assumption about it being a closed loop may be wrong. I see numerous references to AF systems generally being "open loop". In other words the AF system calculates the amount of movement needed to achieve focus then moves the lens there, but does not recheck. So it may over- or undershoot the target. I could not find an authoritative reference from any manufacturer. For what it's worth, here are some posts regarding this issue:
http://arstechnica.com/civis/viewtopic.php?f=6&t=157055
http://forums.dpreview.com/forums/readflat.asp?forum=1029&message=16985680
Assuming it is "open loop" then the AF system consults some sort of table of adjustments based on the inputs it gets, which could vary lens to lens.
Even in a "closed loop" system, there would have to be tolerances. If you want speed you can't constantly adjust back and forth until "perfect", you want to quickly get within a margin of error, and small adjustments may just not feasible with the build quality and tolerances of many, if not all, lenses and AF motors
