I have a Canon PowerShot SX500 IS. However, when I shoot in manual mode at a high shutter speed the images are very dark, almost black. On the other hand, when I use a lower shutter speed later in the day the images come out all white.
What are the possible causes of these problems?
I was looking at some pictures by TSO Photography, and I was struck by how everything in the image seems to be sharp and in focus.
I do realize that to achieve huge depth of field, you set the aperture to the lowest possible value — but doing so causes diffraction, which reduces the sharpness of the picture. Are their any other methods to get such high depth of field (other than focus stacking)?
The camera used in this case was a Canon 5D Mark II — a full-frame camera, so it's not because the sensor is small.
Answer
Unfortunately, Facebook strips the EXIF data from images, a terrible practice, so I can't get his actual settings. However, a wide angle lens with a reasonable aperture that is focussed to the hyperfocal can put a huge portion of the scene in focus. For example: a 16mm lens at f/8 focussed 3.55 feet away effectively puts from just under two feet away to infinity in focus and f/8 isn't going to wipe your sharpness out.
You can understand the concept, and play with some numbers, using the online depth of field calculator to see what I mean. They make a mobile version for various devices too and that can be handy out in the field.
I am thinking of buying a digital SLR camera. What things should I be looking for?
Answer
Things to look for when buying your first dslr:
Price. Far from me to tell anyone how to spend their hard earned cash, but having an idea of what money you want to pay will help.
Ergonomics. Does the body feel good in your hands? What about when you have your lens attached?
What brand? I'm a fan of Canon. Nikon is equally awesome. There are other brands as well, but I recommend the big two: Canon and Nikon.
Beginner/creative modes. Since this is your first camera, having modes that do some automation will ease you into using an SLR.
Entry Level/ Prosumer Level body. If you have a sufficient budget, consider which would serve you better: Buying a more expensive body now, with features that you can grow with, or a less expensive body with fewer features, leaving you more cash more lenses. In terms of producing great images the chain of importance goes: Photographer >>> Lens > Camera Body.
My first dSLR was a Canon 20D, a prosumer body. I chose it because I have larger hands, and the 20D size and weight felt better (twss), and I wanted something I could grow with.
I'm a hobby photographer, and I've just picked up "rules of thumb" and "tips&tricks" here and there.
I have a 50mm f1.4, and I love it.
But due to the extreme shallow depth of field (at f1.4), I sometimes experience that "the other eye" is unfocused. As a hobby photographer, I have learned that one must always focus on the eyes when shooting people, but I wonder if it's considered to be "amateurish" when only one of the eyes are in focus - or if that is considered to be a "cool" effect.
As the "artist" of the photo, I know that it's "my call" wheter I like it or not, but whenever I try to consider the effect, I'm a bit blinded by the extreme shallow depth of field, and thus I think it's a bit cool, but still a bit wrong.
Are there any guidelines here?
(click the image to view full size)
Answer
What should be in focus is the subject of your image: that which you wish to call to attention.
When it comes to people as the subjects, our ingrained behavior is to look at the eyes. This where we look when talking to someone, its what is the focus of our attention. Therefore, when looking at a photo of a person, we notice immediately if the eyes are out of focus...it makes the image look 'not quite right'. Usually you hear such things as the image being 'soft' if the eyes are out of focus. In fact, if only the eyes are in focus, almost no one will complain about your image being 'soft' even though, in fact, it is quite soft.
Having both eyes focused is a creative decision, but it may impact the acceptance of your image. Adjusting the distance or aperture slightly will bring the other eye into focus, as well instructing your subject to move their head, so this is completely controllable. Of course, I suspect your shot is a candid, and you had no control of your subject's head.
You should become familiar with the DOF or Depth of Field calculations, and understand how this impacts your photography. The excellent DOF Master is a great place to start. For example, with your 50mm, wide open at f1.4, at a distance of 1 meter, you have 2cm of focus to work with (assuming APS-C camera). anything more than 2cm out of the plane of focus will be blurry. Play around with the distances and aperture settings to learn the limits of your lenses. For example, by simply stepping back half a meter, you would gain 2.5 more cm of focus distance, and the other eye would easily be in focus.
I've seen the term used, but what is a "diffraction limit", when should I worry about it, and what undesirable effects are a result of it ?
Answer
There have been some very good answers, however there are a couple details that have not been mentioned. First, diffraction always happens, at every aperture, as light bends around the edges of the diaphragm and creates an "Airy Disk". The size of the airy disk, and the proportion of the disk that comprises the outer rings, and the amplitude of each wave in the outer rings, increases as the aperture is stopped down (the physical aperture gets smaller.) When you approach photography in the way Whuber mentioned in his answer:
Think of a scene as comprised of many small discrete points of light.
You realize that every one of those points of light, when focused by your lens, is generating its own airy disk on the imaging medium.
It should also be clearly noted that the diffraction limit is not actually a limitation of a lens. As noted above, lenses are always creating a diffraction pattern, only the degree and extent of that pattern changes as the lens is stopped down. The "limit" of diffraction is a function of the imaging medium. A sensor with smaller photosites, or film with smaller grain, will have a lower limit of diffraction than those with larger photosites/grains. This is due to the fact that a smaller photosite covers less of the airy disk area than a larger photosite. When the airy disk grows in size and intensity as a lens is stopped down, the airy disk affects neighboring photosites.
The diffraction limit is the point where airy disks grow large enough that they begin to affect more than a single photosite. Another way to look at it is when the airy disks from two point light sources resolvable by the sensor begin to merge. At a wide aperture, two point light sources imaged by a sensor may only affect single neighboring photosites. When the aperture is stopped down, the airy disk generated by each point light source grows, to the point where the outer rings of each airy disk begin to merge. This is the point where a sensor is "diffraction limited", since individual point light sources no longer resolve to a single photosite...they are merging and covering more than one photosite. The point at which the center of each airy disk merges is the limit of resolution, and you will no longer be able to resolve any finer detail regardless of the aperture used. This is the diffraction cutoff frequency.
It should be noted that it is possible for a lens to resolve a smaller spot the pixels in an imaging medium. This is the case when airy disks focused by a lens cover only a fraction of a photosite. In this case, even if two highly resolved point light sources generate airy disks that merge over a single photosite, the end result will be the same...the sensor will only detect a single point light regardless of the aperture. The "diffraction limit" of such a sensor would be higher (say f/16) than for a sensor that is able to distinctly resolve both point light sources (which might be diffraction limited at f/8). It is also possible, and likely that point light sources will NOT be perfectly focused onto the center of a photosite. It is entirely plausible for an airy disk to be focused at the border between two photosites, or the junction of four photosites. In a black and white sensor or foveon sensor (stacked color sensels), that would only cause softening. In a color bayer sensor, where a square junction of 4 photosites will be capturing an alternating pattern of GRGB colors, as airy disk can affect the final color rendered by those four photosites as well as cause softening or improper resolution.
My Canon 450D, a 12.2mp APS-C sensor, has a diffraction limit of f/8.4. In contrast, the Canon 5D Mark II, a 21.1mp Full Frame sensor, has a diffraction limit of f/10.3. The larger sensor, despite having nearly twice as many megapixels, can go an extra stop before it encounters its diffraction limit. This is because the physical size of the photosites on the 5D II are larger than those on the 450D. (A good example of one of the numerous benefits of larger sensors.)
Wrenches in the mix
You may often come across tables on the internet that specify a specific diffraction limited aperture for specific formats. I often see f/16 used for APS-C sensors, and f/22 for Full Frame. In the digital world, these numbers are generally useless. The diffraction limiting aperture (DLA) is ultimately a function of the relation of the size of a focused point of light (including the airy disk pattern) to the size of a single light sensing element on a sensor. For any given sensor size, APS-C or Full Frame, the diffraction limit will change depending on the size of the photosites. An example of this can be seen with Canon's EOS Rebel line of cameras over the years:
Camera | DLA
--------------------
350D | f/10.4
400D | f/9.3
450D | f/8.4
500D | f/7.6
550D | f/6.8
The story should be similar for film grain size. Films with finer grain would ultimately be more susceptible to diffraction softening at lower apertures than films with larger grains.
Diffraction is often touted as an image killer, and people talk about the "diffraction limit" as the point at which you can no longer resolve an image "usefully". On the contrary, the diffraction limit is only the point where diffraction starts to affect an image for the particular image medium you are using. The diffraction cutoff frequency is the point at which additional sharpness is impossible for a given aperture, and this is indeed a function of the lens and physical aperture.
The formula for diffraction cutoff frequency for (perfect) optical systems is as follows:
fc = 1 / (λ * f#) cycles/mm
This states that the reciprocal of the wavelength of the light being focused multiplied by the f-number of the lens is the number of cycles per millimeter that can be resolved. The diffraction cutoff frequency is generally the point where resolution reaches the wavelength of the frequencies of light itself. For visible light, λ between 380-750nm, or 0.38-0.75 microns. Until the cutoff frequency has been met for a given aperture, more resolution can be achieved.
Whubers sequence of images above is a decent example of the effect of diffraction, as well as the effect of optical aberrations when the lens is wide open. I think it suffers a bit from some focus shift due to spherical aberration, so I have created an animated GIF that demonstrates the effects of changing the aperture of a Canon 50mm f/1.4 lens down from its widest aperture to its narrowest, in full stops.
(Note: The image is large, 3.8meg, so let it fully download to see the comparison of sharpness at each stop.) The image exhibits marked optical aberration when shot wide open, particularly Chromatic Aberration and some Spherical Aberration (there may be some slight purple fringing...I tried to get focus dead on.) Stopped down to f/2, CA is lessened considerably. From f/2.8 through f/8, sharpness is at its prime, with f/8 being ideal. At f/11, sharpness drops ever so slightly, due to diffraction. At f/16 and particularly f/22, diffraction visibly affects image sharpness. Note that even with diffraction blurring, f/22 is still considerably sharper than f/1.4 or f/2.
I always wondered what are the best techniques, hints, and tips for a great panoramic shoot?
I'm doing a personal project taking portraits of friends, family and acquaintance. Most of them are not used to having their portrait taken and I don't intend to portray them as models either. I show them other portraits in the series beforehand so that they know what I want. I'm looking for nicely lit portraits without excessive makeup, just like they look in everyday life, but as flattering as I possibly can.
The problem is that almost everyone get very nervous days before and when they finally stand in front of the camera they've overdone their makeup, put too much thought into what they're wearing and they even look scared in the photos. When they've seen the first few shots they usually relax a lot, but they're still overdressed or have used too much makeup. Right now I often have to take their portrait a second time when they're confident I won't let them down and present them in an unflattering way if I want the natural look I'm looking for.
How should I approach taking planned portraits of people and make them feel comfortable and not feel the need to overprepare?
I have a Nikon D850 with portrait lens AF 105mm f/1.4. I'm just learning how to make good pictures. We purchased this camera not for business — we have kids and want to make every possible memory. I'm using A mode, but often when I make pictures, one kid's face is in focus but another one is blurry. (I have twins so it rarely happens to get a good picture with both kids in focus).
What setting do I need to change? Kids birthday is this weekend and I'm the one who will take pictures of all kids.
I have a Yongnuo YN-568EX flash and I use it with a Nikon D7100.
If I buy another two more Yongnuo flashes of any model other than a YN-568EX, in principle will they all work together using at least one of the many types of setup?
If the answer is yes, does the same apply to different models from another brand? e.g. Could you use a Nikon SB-900 and SB-700 together off of the same camera?
Sensor cooling is a common technology to get less noise. Why isn't it available on high-end D-SLRs ?
(see http://www.andor.com/scientific_cameras/ikon-m_cooled_ccd/ for an extreme example)
I'm not saying D-SLRs should be cooled with liquid nitrogen. Just some cooling system !
Note: This is not a duplicate of "Exposure Triangle things". This is more related to Camera's auto settings i.e. Aperture and human's manual settings i.e. Shutter and ISO and their co-relation.
I am a previous user of Point and Shoot camera (Canon Powershot series) and recently shifted to canon EOS 80D. In Shutter Speed Priority Mode, we adjust Shutter and ISO and camera adjusts the Aperture. Higher the Shutter speed would require higher the ISO, otherwise, the picture would be darker.
I tried to set it in Live View, but sometimes Live View is not accurately understandable in some environments.
Is there a formula to quickly calculate ISO according to shutter speed we set?
Answer
Yes if you know the aperture and light level. The "reference point" is that at an exposure value of 0, you will get a correct exposure with a shutter speed of 1s, an aperture of f/1.0 and ISO 100. From there, it's just a matter of counting stops to work out where you need to be: for example, if your light level is -2 EV (2 stops darker), your aperture is f/2.8 (3 stops darker) and you're at ISO 6400 (6 stops brighter), you need a shutter speed 6-2-3 = 1 stop faster or 0.5s.
Mathematically, you can calculate it all via:
But by the time you've actually gone as far as measuring your light level, there are probably better ways to have solved all this.
When photographing protests and rallies, how do you show that you are not a protester and just a photographer to avoid police crowd control tactics? What do you do if the crowd you are in is getting particularly rowdy? Any other tips and best practices?
Answer
"how do you show that you are not a protester and just a photographer to avoid police crowd control tactics?"
You don't, really.
On the one hand, the vast majority of protests are peaceful low-key sort of things where the police are just watching what's going on (if they're even there), or ensuring protests and counter-protests remain separate. They're basically not worried about you or what you're doing.
And on the other hand, if they've closed ranks, they're worried about everyone and they literally don't care if you're a protestor or "just a photographer." Press accreditation might get you through a police line, but even that's no guarantee; plenty of accredited journalists were caught up and detained in the G8/G20 protests in Toronto.
So, for the most part, being a photographer at the front line of a protest means you need to think in much the same way as a protestor at the front line:
Be aware of the overall situation. Are things getting hostile or escalating? Have the police blocked the route? Have they blocked all the routes (bad sign)? Are they demanding protestors move back? Is anyone provoking the situation?
It's usually safe. In fact, photographers will often be just as plentiful as protestors at the police line, as that's where the good pictures are. This was true even at the most violent protests during the Edinburgh G8 in 2005. You are more likely to get caught up in other people's scuffles, but that's what being at the front entails (see above about "being aware").
If people are being arrested, the police do not discriminate. You're in the crowd, it's easier for them to detain you and sort it out later. This entails being prepared to be arrested:
If the tear gas (etc) is being deployed, and you're on the wrong side of the police lines, it's basically out of your hands. Do not panic, try to stay out of any clashes, and stay away from anyone throwing anything back at the police (or be aware of the risk you're taking to get that particular picture). Staying where you are is often a surprisingly good choice. Do not assume having a camera means you aren't a target, if anything, assume the opposite. See above about being arrested.
NB: this is based on my experience in Canada, Switzerland, and the UK. Probably decent advice for most western-style developed democracies, though variations certainly exist. Concrete local knowledge will always trump general advice.
I'm not sure if it's my particular copy of the lens, but I find the focusing ring of the Canon 24mm TS-E Mark II a bit too loose. It's too easy, in other words, to change the focus by mistake.
I bought this lens a few months ago (brand new). I think that's the way it is, but I find it weird it is so loose by design.
Would it be possible to have it tightened? If not, is there a workaround?
Answer
I've got an EF 24-105mm f/4 L IS that is 'well broken in' with a very loose zoom ring. When the camera is pointed straight down, as it does when hanging from a sling or neck strap, the front of the lens creeps all of the way out to the fully extended 105mm position.
I use a plastic wristband bracelet stretched around the lens barrel with part of the width of the bracelet on the zoom ring and part of the width on the stationary part of the lens barrel. The band provides enough resistance to prevent the zoom from creeping due to gravity. How much of the band is on the zoom ring and how much is on the barrel determines just how much resistance is added.
The same type of band can be used to give a focus ring more resistance. There's even a company that markets such bands specifically for camera lenses, but I've never tried them because they seem to be the same as the rubber wristband bracelets I already have that work for me.
The TS-E 24mm f/3.5 L is slightly smaller in diameter (approximately 78mm) at the focus ring than the barrel of my EF 24-105mm f/4 L IS (approximately 83.5mm). The TS-E 24mm f/3.5 L II is slightly larger in diameter (approximately 88.5mm) than my EF 24-105mm f/4L IS. I would expect you could fairly easily find a generic plastic/rubber wristband of the type used to promote charities and businesses that would fit either one.
From a comment by the OP to another answer:
I bought this lens a few months ago (brand new). I think that's the way it is, but I find it weird it is so loose by design.
The focus ring of all Canon TS-E lenses I've handled are fairly well dampened without being stiff. If the lens is under warranty, I would not hesitate to contact Canon Service. If you send it to them and they say there's nothing wrong with it, at worst you're out the price of shipping.
I know there is an answer that covers recovering photos from sd card and plenty of links online but I need one that can cover RAW files (specifically sony raw files in my case. arw). Is there one that can do that?
I notice that when taking photos using my camera phone, the file name consists of the date and time. (e.g. 20131101-110015.jpg)
However, most point and shoot and DSLR cameras do not. Their file name is usually in a sequence like DCM0011.jpg
Is there a way that we can set a camera option so that it will create the file with a name that contains the date and time?
With reference to a Point and Shoot Camera Samsung EX1 vs a Camera phone Samsung Galaxy S2
Answer
This comes down to software patents — not on dates, but in a way that limits filenames. The only filesystem which is widely available and cross-platform is FAT, the venerable Microsoft DOS filesystem. It works on both old and new versions of Windows, worked on OS/2, works on Macs, works on Linux, and there are plenty of embedded implementations for the mini operating systems that run on cameras. It's old enough that it is public domain.
But, there's a catch. The original version only allowed filenames of eight characters plus a dot plus the three-character extension. The extensions which allow longer filenames are much more recent, and a while back Microsoft was doing some serious saber-rattling over collecting royalties. That means most cameras — and the DCIM standard — take the safe route and avoid code to generate long filenames. And that means human-meaningful date and time isn't viable, because it's just plain too long.
This is backed up by a technical manual for an embedded SD card driver, which notes:
Microsoft offers licensing for the use of its FAT filing system on a per unit sold basis. However it is generally viewed that this only applies to applications that implement the patented long file name system (LFN). It is our understanding that if long filenames are not used then no licence fee is due, however you should ascertain if you agree with this view yourself (to our knowledge Microsoft have not stated this but others have determined this based on original releases of the FAT standard by Microsoft).
Cameras or cameraphones which do write longer filenames have either paid Microsoft, are using a different filesystem, or aren't worried about the legal threat.
I would like to know if there any good online resources for indoor product photography ?
Preferably with a Table Top setup.
Im looking for commercial grade product photography tutorials/resources.
I would like to add that I already own a Tabletop setup. It includes 3 Lights, a Cube box where the product is placed etc. I would be using a Nikon D90 camera.
Answer
The light tent/cube isn't really a product that will help you extend your photographic skill. It's designed to make the process easy and make anything look pretty good: just put the object inside the tent, position the lights around so that the whole tent is lit, and take a photo. The tent won't allow you to add a hard light for an accent, for example, because it's, well, an enclosed tent.
To really grow you need to move to just working on a table top with additional lights and modifiers. A couple umbrellas or softboxes will let you light the subject in very much the same way as the tent does, but you'll now have room to add an accent light or two, which might be responsible for showing off some detail on the product, or better lighting a difficult area of the product.
Strobist is a great place to learn about lighting anything. Once you understand how to use the light and light modifiers, you can apply it to anything, including product photography. If you want video, I can highly recommend Strobist's Lighting in Layers DVDs.
I have a trip scheduled this weekend where there is a lake with thousands of winter birds. I will be using Canon EOS 550D and Canon 100-400mm USM IS lens. I will also have a wide angle lens to shoot landscapes with birds in it. I have no prior experience in birding, so I want to know what are the things that differ from shooting day-to-day pictures to shooting birds? How should I go about finding a bird and approach it properly? How do I increase the chance of getting better photos? Suggestions are welcome.
Answer
Be Ready!
First thing first, when you can, always keep your eye trained on the subject through the lens. Birds are quick, alert, and attentive, and when they do something interesting thats worth capturing, you rarely have time to bring the camera to your eye, frame, focus, and get a shot. So its critical that you are watching the bird through the lens as much as possible, and have the shutter button half-pressed (to activate IS), so you are ready to go the moment something really interesting happens.
Be Obvious
You can try to sneak around and attempt to get close without a bird noticing you, but that rarely works. Pretty much every bird WILL notice you, and they will have noticed you long before you think they have. The best approach to getting close is to simply be obvious, and don't sneak. Predators sneak. Photographers look. Train the birds around you that your not a predator, just some clumsy mammal tromping around on unfamiliar ground that gives them an occasional look.
Be Courteous
No one likes it when you stare...including (or perhaps, particularly) birds. Don't zero in on a bird and keep it in your sight for too long...at least at first. Predators stare. Photographers look. Train the birds around you that your just a clumsy mammal that has a vague curiosity about it, and they'll get back to their normal routeen. You'll have a chance to get closer that way, and they shouldn't be as jittery when you do if they think you aren't preparing to eat them.
Be Noisy
If you try to sneak up on a bird, any noise will alert them to your presence. The snap of a twig or the clack of a mirror and shlink of a shutter will at the very least alert them, and likely make them fly off. Take shots, early and often, and let the birds hear the sound of your camera. Take shots when your far away and can't really get anything good, just so you are making the kinds of noises that are "normal" for a clumsy, mammalian photographer.
Be Indirect
Don't go strait for the shot (or the bird) strait away. Be a little random and indirect, take a meandering path on your way to getting closer and closer to your subject. Predators track. Photographers meander. Be a noisy, clumsy, meandering but courteous mammal that exudes a presence of mild annoyance, and you should evoke less fear...and more curiosity, than a sneaky approach.
Be Normal
All of that basically boils down to "Be Normal!" The fundamental essence of the rules above boils down to "Don't look, sound, or seem like a predator."
Fine tuning your approach
When it comes to birds, there are a few different types, and they all require some subtle changes to how you approach them and how you photograph them. Common types of birds include the small migratory song birds, like finches, jays, black birds, doves/pigeons, etc.; there are wading and water birds like egrets, ibises, ducks, geese, and the like; and there are birds of prey and scavengers. Photographing each will take some slightly different techniques on the basic guidelines outlined above.
Small migratory birds are often the toughest. They are a primary source of food for many birds of prey, as well as for many carnivorous mammals. They also tend to be rather feisty, are constantly on the move, and are often prone to attack (friendly or malicious) from their own kind for one reason or another. That makes them particularly alert and jittery, and as such they may take a little longer to acclimatize (although it also depends on the bird and the environment.) You might need to be a little slower and less extreme in your "beeing normal"-ness. Don't make too much noise, but be careful not to appear like a predator. Just make sure they don't see you as a threat, and you should gain at least a little curiosity from them. Many song birds are brightly colored, and framing them against a background of contrasting color can often yield great results. Younger birds tend to be more curious than seasoned adults due to their lack of experience. You might get some of your best shots from a yearling. It should be fairly easy to get shots of young in a nest, as small birds don't pose much of a threat (although they will often try.) Be courteous and don't disturb a nest when you find one, unless there seems to be something wrong already (like a nest that may have been scavenged by a predator...in which its up to you to help or not.)
Wading and water birds are a bit different than smaller migratory birds. They tend to be very shy, however they are not as quick to disappear in a single hop and a short flight. When they do fly, they usually fly more slowly, and can make excellent in-flight shots, especially when framed against a nicely contrasting blurry background (longer focal lengths and an f/5.6 or wider aperture really help here...f/4 or better is ideal.) You will need to learn some panning to capture water fowl in flight, and often to catch them gliding along a lake or pond surface. Many long-legged wading birds, from small ones like sandpipers and snipes, to larger ones like egrets and ibises, tend to slowly wade along the shores of their feeding ground...always away from you. Its hit or miss whether they will ever really "get used" to you, however if you give them enough time, they will usually stay close enough for you to get some decent shots. A lot of these birds blend VERY well into their backgrounds, so you may find yourself spending more time finding the right composition of contrast than you do actually photographing the birds themselves. Their patterns tend to match closely with near backgrounds, so finding angles which puts a lot of distance between them and the bulk of the backdrop will assist in isolating the bird from their surroundings (maximum aperture is always recommended.)
Birds of prey tend to be a bit more confident than other birds. Perhaps its the talons, perhaps its the razor sharp beak. Either way, they are not as quick to jump up and fly off at the first sign of disturbance. Birds of prey do seem to expect a certain formality of etiquette, however...particularly when they are feeding. "Be normal", but be as courteous as you can, and try to stay hidden if you want to capture a raptor feeding. Being indirect can also be a valuable tool in closing the gap between you and your subject as well. Looking like a dumb, lowly human seems to satisfy their superiority. ;) A bird of prey can, in the blink of an eye, take off after some unseen prey. It is critical that you have your eye to the viewfinder, finder half-down on the shutter button, be in focus, and ready to take the shot when you zero in on a bird of prey. Autofocus capabilities can be paramount here as well. Quality AF, with as many cross-type focus points, subject tracking, servo-action, etc. will all be extremely helpful when tracking and capturing any bird of prey snatching a meal. Solid panning and tracking skills are also paramount here, as some of the best bird of pray shots are right before and at the moment of capture.
Exotic Birds
I personally do not have any experience photographing exotic birds in their natural habitats. By exotic birds, I mean many of the large (and frequently African) ground or wading birds like storks, the huge flightless birds like ostriches and emus, birds of paradise, southern sea birds like the albatross or northern migratory birds like geese, or penguins. I can't really offer much insight when it comes to photographing them. Based on what I have seen in documentaries, penguins seem to be largely oblivious and fairly curious of humans, and photographing them in any environment should be pretty strait forward. Albatross are often huge, and generally seem focused on eating, staying warm, and eating, and occasionally a little love and a little flight school...so be normal tactics should work well with them. I can't give a whole lot of advice on any other type of bird, as I simply don't have any knowledge about them outside of zoos and documentaries. Birds of Paradise, which are the primary residents of the rainforest of New Guinea, are probably a lot like any other song bird, and I would expect the same tactics to work with them.
When preparing a photography contract, what should be included? I'm sure the experienced shooters have examples of things that they always include in a contract or things that they omitted but later wished they had included.
What are some must-haves or things to watch out for when preparing a contract for a client? I understand that answers may vary based on type of photography (events, portraits, etc) so noting that is probably helpful.
I have just been left some photography equipment. The item is made up of two parts: a flat square and a circular piece together with a holder and a number of adaptor rings. I am used to the circular polarizer, but am at a loss as to how this works.
I was just wondering if anyone could provide names and a bit of background on the Operating Systems the current day DSLRs (namely, Nikon, Canon) use.
Answer
So far what we know based on ML work
DRYOS version 2.3, release #0023
DRYOS version 2.3, release #0039
DRYOS version 2.3, release #0043
DRYOS version 2.3, release #0044 or #0049
DRYOS version 2.3, release #0047
I'm generalizing but I see in Canon P&S they tend to reuse DIGIC processors so a quick check on a Wiki indicated that DRYOS is used.
It isn't specifically mentioned but ML developers indicate that they think this DRYOS is a derivative of uLTRON. They also did indicate that some concepts in DRYOS could be compared to or understood from VxWorks.
BusyBox 1.4.2 (Linux Kernel)
BusyBox 1.13.4 (Linux Kernel)
NEX-7
Sony firmware hacking project got it's own website at http://hackingalpha.wikia.com and forum at http://www.nex-hack.info/
My 3 lenses all have a different size thread. (77, 67 and 58mm) I am to purchase a good CP filter for the 77 and 67 thread. I don't have any filters for the 58mm thread lens but I was thinking about perhaps getting a step-up ring and use my 77mm filters on the 58mm lens.
Are there any known issues with using filter step-up rings? I am thinking maybe even getting only one good 77mm CP filter and use with with all my lenses with a pair of step-up rings.
Any thoughts?
Answer
The only thing you have to be mindful of is with wide angle lenses. You just want to make sure that with the step up ring and filter attached that you don't see the filter edge in the field of view. Slim filters can help with that. Otherwise it's just fine. I do the same myself with 77mm filters.
As hobbyist & professional photographers, what opportunities are available if we wanted to volunteer our services to a charitable organisations?
Any ideas? What sorts of organisations might be looking for volunteers to provide photographic services?
I would love to hear details from anyone with experience doing something like this.
Answer
I occasionally volunteer my photography at historical societies. I have a keen interest in photographing old and disused structures and historical sites, so if I can get access for free then I'll subsequently give the photos to the group as well. Sometimes they will show you around the sites ask you to photograph important objects. This process basically serves as free documentation for them and you get to enjoy a day in some interesting place.
I haven't heard of places like the SPCA or RedCross or something needing photographers specifically, but i'm sure if you were to offer your services they might come in handy some time.
Hope that helps,
I do landscape photography, mostly shooting at dawn or dusk, but I never shoot during the day, the light is just too harsh. I've got a single polarizer and a few ND grads, but nothing else.
What filters, or techniques, can I employ to control daytime light while bringing out natural colors usually drowned out from the sun?
I am not professional photographer , but i have a professional camera (Canon).
I had shoot my pre wedding photos with this camera. So when i was open , it will be converted into black and white after few second. So I found it is cr2 format.
I don't know the photo editing, so what i have to do with this format.
How i can convert into jpeg format with same quality.
Some online converter can not revert actual image.
Answer
The files are in RAW-format, which is actually great if you are going to post process them! Although, if you simply want to convert them to jpeg, as close to what your camera woud have possibly done, you should use Canons editing tool "Canon Digital Photo Professional" aka "DPP". Here you can do lots of stuff (I'll be posting a link below) including converting your images to jpeg like your camera would have.
http://cpn.canon-europe.com/content/product/canon_software/inside_digital_photo_professional.do
I'm considering buying a Canon 760D / Rebel T6S but it lacks autofocus microcalibration. It's an expensive camera and all upper models including the 70D offer it - so is it something that I can accept or should I invest in 70D? Canon 760D has a 24 MP crop sensor so exact focusing may be very important to avoid soft pictures.
I use only original Canon lenses but change them very often, and as most of them have plastic mounts which may wear out over time, microcalibration may be a very important feature to have - there must be a reason that all upper line bodies offer it.
Answer
... is it something that I can accept or should I invest in 70D?
Unless you're a professional, a camera is never an investment. It never appreciates. It's an expense.
Depends on what and how you plan to shoot. If you think you'll be doing focus-critical work, like macro shooting, where you work with a tripod and manual focus, it's not at all critical, as you're bypassing the autofocus system altogether.
If you're planning on using supertelephoto lenses on fast-moving subjects and need the AF to nail focus each time, then it can be much more critical.
Canon 760D has a 24 mp crop sensor so exact focusing may be very important to avoid soft pictures,
This, in and of itself is not a factor that means you require AFMA. In fact, the majority of entry-level dSLRs that don't have AFMA have the same resolution, so a number of folks are apparently getting by just fine without it.
I use only original Canon lenses but change them very often, and as most of them have plastic mounts which may wear out over time, microcalibration may be a very important feature to have ...
Actually, what this is telling me is that you only own entry-level lenses (EF 50mm f/1.8 and the EF-S 18-55 kit are probably the only two lenses with plastic mount plates). In fact, nearly all lenses these days have plastic mounts. And if you end up with a lens/body combination that is so out of calibration you notice serious AF issues, you can always send that gear to Canon service and have them calibrate the gear for you (i.e., do the adjustment).
To my way of thinking, it's mostly a convenience feature, unless you a) are completely unwilling to send a lens/camera combination to Canon to have them calibrated, or b) have a large number of lenses, or c) do a lot of shooting where autofocus accuracy must be spot-on at all times, and d) shoot wide open with fast lenses all. the. time.
(there must be a reason that all upper line bodies offer it).
The main reason is that successful professionals who can earn enough to cover the cost of high-end gear tend to use high-end gear to make things easier on themselves and to save time. Better glass generally means less post-processing. Harder-wearing bodies can take more wear and tear. And having AMFA means you don't have to wait on Canon Service to do adjustments for you.
I shot with a 350D/XT for four years and never felt the need for AFMA. I also used that camera body to shoot birds with an EF 400mm f/5.6L USM. I never needed to send the combo into Canon for calibration. I now shoot with a 50D and 5DMkII, both of which have AFMA, and I've probably used the feature a grand total of twice, and it only helped in one instance, because my methodology of adjusting the AF calibration was less than optimal (it's why I happily use Magic Lantern's auto dot-tune feature).
Note that Michael said he only noticed he needed AFMA when he used a $2000 telephoto L lens. And note how I said I used an $1100 supertelephoto L and never really did. In my book, this is a gracenote/convenience feature; not a have to have, and not a great excuse to indulge in feature-greed. To me, Don't get a 70D just for AFMA. Because, frankly, you probably need the cash you'd save for better glass. And the 80D was just announced. :) The 70D's used price will probably be dropping soon...
I have got an old lens Helios 44-2 (58mm f/2 M42 mount) that I want to use for portraits on my Nikon D3100. I used an adapter (without optical element) to mount the lens. I want to really try this before going for more expensive non-cpu prime lenses.
In manual mode I can not select the aperture but only shutter speed and exposure. Moreover there is no option to specify non-cpu lens parameters.
The images turn out to be darker even at f/2 and out of focus.
I have read posts on using live view for focusing and tried that. It improves the focus a bit but not the brightness. Can someone suggest a well documented procedure for improving brightness and focus?
I've just noticed that whilst shooting with my D5100 using M mode settings reset after each shot.
Say, the camera is on a tripod pointing to an object. I've balanced out the exposure to a 0, aperture set to F/8 (this doesn't change btw) and the shutter speed is set to 1/15. I take the picture (camera hasn't moved) and the exposure level and the shutter speed have changed to some random settings (+2 EV exposure and 1/250 shutter speed - it's different every time though).
I've searched everywhere, but couldn't find an option that would allow me to save/lock my current settings providing the the image in the view finder doesn't change.
Ideas?
Answer
This behavior is caused by automatic exposure bracketing.
I've had someone with a Nikon D5000 behaving the same way in manual mode, and it turns out that automatic exposure bracketing caused this problem. My Pentax K-5 behaves the same way if the drive mode is set to exposure bracketing in manual exposure mode.
If this does happen to you again, make sure that bracketing is not set and disable it if it is. You do not need to reset the camera to factory defaults.
I bought a used Fujifilm X-E1 camera body on ebay (details of setup below), and am trying to use it with an adapter and a set of K-mount lenses that I already owned. The lenses all worked fine with my old film SLR. After buying a memory card and putting in batteries, I seem to have a fully functional camera, except that ... er, it doesn't take pictures. I can see through the lens, I get a preview and indicators on the LCD, and it works when I set the aperture and focus. But when I depress the shutter button, nothing happens. I don't hear a click from the shutter, and there is no indication on the user interface that a picture has been taken.
My question is how to go about troubleshooting the problem. It's been 15 years since I've used my old film SLR, and I've never used a digital manual-focus camera, so it's quite possible that I'm just making some silly newbie mistake.
Page 3 of the manual describes an "indicator lamp" that tells you when the camera is ready to shoot. This never comes on for me, but as far as I can tell from the documentation, this is normal in manual focus mode -- it should only come on when you're using the camera in autofocus mode.
Setup:
Steps I'm going through:
Take off lens cap.
Turn on camera.
Set manual mode.
Set exposure to 1/500 s.
Push shutter button, feel a first and second click.
There is no sound from the shutter. Nothing appears to happen in the LCD user interface, and there is no indication that an exposure has been made.
Answer
I'm not familiar with this camera, but is it possible that you need to enable some kind of "release shutter with no lens attached" setting? What I'm thinking is, since there is no electronic communication between the camera and adapter (I assume), maybe your camera believes there is no lens attached.
Yes, I just checked the manual. See page 72, setting "Shoot without lens".
All three lenses are available at a local store near me:
I plan on doing macro and portrait photography and have the ff thoughts so far:
so as you can see, I'm leaning towards 105mm f/2.8 or 85mm f/1.8 and less towards the 85mm f/1.4. However, I don't want to finalize the decision as many also claims that the 85mm f/1.4 is so good.
Any professional insights to add in helping me make the decision?
Answer
This is all very personal of course. I have the 85mm 1.8, and a friend has the 1.4. I would gladly do an even swap, but at more than double the price, it wouldn't be worth it to me to pay extra for the 1.4. If I did weddings maybe I could justify it, but I'd rather put the savings into something else. It's a bit more solidly built, slightly better IQ, but for me, no, not worth the extra cost.
I also have the 105mm macro. I get a lot more use out of it than the 85mm lens. I use the 85mm solely for portraits (but when I do people shots it's my go to lens).
I never use the 105mm for portraits. It's usable, but it doesn't have the bokeh of the 85mm lenses. Doesn't AF that fast either. For portraits I either use the 85mm or an 80-200 zoom, which towards the 200mm end throws the backgrounds out of focus and has nice bokeh.
AF on the macro is especially slow, and hunts a bit, at macro distances - you may be manually focusing up close. The VR is sometimes usable doing hand-held garden shots (less than 1:1). I've never known AF noise to scare off insects, but I could be wrong.
What I would recommend is finding an old 105mm AF-D. They would be half the price or less than the VR. Buy one of those, plus the 85mm 1.8 and you can have both for the price of the other lenses (85mm 1.4 or 105mm VR).
When someone wants to compliment a 35mm sensor, he can say that it's [almost] as good as medium format. Medium format appears to be the gold standard where image quality is concerned.
But. I'm usually working with natural light using my lenses wide open, and the widest lenses that I've seen for Hasselblad or Leica S2 are f/2.8, which I consider very dark. Also, when I watch clips on youtube concerning medium format, people usually use those lenses with artificial lighting, which also confirms my impression that medium format cameras aren't as light sensitive as DLSR systems.
So my question is - let's say I'm working with 1D X and 85mm f1.2. Is there anything in medium format sector, that can beat that combination when working in low light conditions?
Answer
Theoretically if you keep the size of the entrance pupil and field of view the same then you will capture the same total amount of light regardless of the format.
If your medium format sensor in 1.6 times larger (which is the upper end available today, the Leica S2 you mention is only 1.25 times larger), then to match your 35mm DSLR and 85mm f/1.2 lens would require a 135mm f/1.9 medium format lens.
f/1.9 lenses are rare in medium format (mainly for weight reasons), the only current(ish) lens I know of is the Mamiya 80 f/1.9 - this lens can compete (in terms of total light gathered) with a 50 f/1.2 on a DSLR.
However even though the 80 f/1.9 lens transmits same total amount of light as a 50mm f/1.2 that doesn't mean the medium format system with this lens is as good in low light - this is due to the sensor being less efficient.
Medium format digital backs are most commonly used in landscape, architectural or studio photography where a certain amount of light is guaranteed by the use of a tripod or large artificial light sources. The sensors are optimised for size, producing accurate colours and fine tonal graduations as opposed to offering high sensitivity.
For this reason nothing commercially available today can match the low light performance of a 35mm DSLR.
I was reading again the manual of my camera (Canon 50D, but I am sure that each DSLR offer the same kind of functionality, albeit I don't know the exact names adopted) and noticed the issue of Picture styles which I had overlooked in my first reading.
In short I think that they are a collection of various calibration settings (more or less enhanced colours, things like that...). Those that are available on my camera are:
These styles are so important to deserve a direct button just under the LCD screen of the camera (I guess this is useful for simplifying the use of the camera in the basic modes as opposed to manual / less automated ones).
And now for the question:
As a bonus (don't know if it deserves a separate question, in which case I will ask it again), what is the difference between Neutral and Faithful?
Answer
Styles are indeed an information layer on top of the RAW image data. As you wrote, setting a style is a non destructive operation when you shoot RAW, and the RAW processor (DPP, for example) lets you change styles while developing the image.
If there is a reason to select a style, it is to take out yet another step in the development process. If you know beforehand what style you prefer, setting it on shoot-time will save you changing it in post (same logic applies to the other settable presets, like white balance, etc.).
It seems like the Foveon sensor should be able to produce better images, because it's not dependent on the separate red, green, and blue pixels as exist on most digital cameras. However, cameras equipped with Foveon sensors are pretty much nonexistant. Why?
(Side note: This question was inspired by Bayer Filter answer where the Bayer filter potentially caused problems...)
Answer
What happened is that Sigma bought Foveon and put a lot of pressure on them to produce a sensor that is actually capable of competing with standard DSLR sensors. Now that Sigma is building the whole camera and sensor, there is a lot more focus on producing a compelling end-product.
Last year Sigma announced the SD1 which uses an APS-C (1.5X crop) sensor with 15 million photosites. They way they count Sigma calls it a 46 megapixels sensor. They have not released many details to members of the press (me at least) but is expected to be available by this summer.
There are still several Sigma cameras (DP1x, DP2s, SD15) in production which use the 1.7X Foveon sensor with 4.5 million photosites (aka 14 megapixels).
I took these pictures with my Canon EF-S 15-85mm f/3.5-5.6 IS USM lens this morning:
Would somebody please tell me that what is that white part in the lower right corner of the picture?
EXIF info: F/8 ISO 100 1/125sec Focal Length : 85mm 
And what are these circles in the center of this picture?
EXIF info: F/8 ISO 100 1/125sec Focal Length: 15mm 
Thanks
Answer
It is "lens flare" in the first, but in the second, it is the reflection of the black internal parts of the front of your lens which are illuminated by the direct sun reflecting off the inside of your UV filter.
During vacations and travel I tend to use my Nikon D90 and a 18-200 VR (image stabilisation) lens.
I was very annoyed (and had no explanation) when I found images to be unsharp, which had be made in wide (20-30mm) and very fast shutter times (1/800s).
The images obviously had been unsharp from camera shake, but this was improbable if not impossible at 1/800s and 30mm using an VR/IS Lens.
Later someone told me he read somewhere in the internet that VR lenses tend to blur pictures at very short shutter speeds like mine.
I paid more attention to it, and my blur problems all are with VR lenses at very fast shutter speeds.
So I'd like to know: why to VR lenses blur pictures? At what speed do they ruin my pictures? Is there anything to do about this apart from disabling VR or better not buing lenses with VR/IS?
(interesting side note: as far as he told me only systems with VR/IS in the lens are prone to this problem. Systems with IS/VR in the DSLR Body do not have this problem).
Answer
As it is when questions are burning me, I searched the web for more information about this and found a very good article by Thom Hogan explaining the Nikon VR system (and it's limits):
His findings explain my problems: he says to be careful with VR with shutterspeeds of 1/500s and below, since these are prone to problems since they come too close to the sampling rate of the VR system.
Due to the pitfalls of the VR system he recommends disabling VR if you don't need it.
The article is a very good read, it explains a lot of details of VR, the difference between normal and active VR, VR and the new VR II, how to use VR when panning or standing on a moving platform...
Is there any utility which will read a photo's date and time from its EXIF data and embed it into the corner of the photo?
Answer
If you are comfortable with command line tools from ImageMagick, you can do something like this:
convert orig_image.jpg -gravity NorthWest -annotate 0 "%[EXIF:DateTimeOriginal]" new_image.jpg
You can run this to batch process all your images.
Details
ImageMagick has an array of command line tools to do different things with image. I'm using the convert tool here with annotate option to annotate a text on the converted image. There are whole bunch of other options that can be used to control font, color, shadow etc. Explaining all will be out of scope of the question, but you can take a look at this doc.
%[EXIF:DateTimeOriginal] is a shortcut for:
identify -format "%[EXIF:DateTime]"
You can do something like: identify -format "%[EXIF:*DATE*]" to see what all date related strings are stored in exif.
Galen Rowell in one of his books talks about the "The most memorable, mind-changing photograph of all time. A color landscape shot taken without a tripod by an amateur". Does anyone have a link to a copy of this or can explain what is special about it?
Answer
Earthrise by Apollo 8 Astronaut William Anders - sounds like he was advocating that sometimes all the training or equipment doesn't make a photograph good, but sometimes a subject can be just THAT inspiring.
Credit: NASA
I'm looking for an iPhone app that features exposure compensation, any suggestions?
Answer
Camera+ claims to let you adjust the exposure (which is what exposure compensation does)!
Possible Duplicate:
Why do zoom lenses and compact cameras have varied maximum aperture across the zoom range?
It is rather common with zooms that the maximum aperture changes (in fact, decreases) with increasing focal lenght. At the same time, it is possible to make zooms with constant aperture (typically and not surprisingly, much more expensive).
What is the technical reason for the decreased aperture? After all it seems naively that the blades could be opened independently of what is happening to the focal length.
Is it to mantain the same level of image quality (distortion, aberrations, vignetting) at each focal length?
Or is there some "more fundamental" reason for this engineering decision, which can be overcome only in more complex/expensive designs?
Answer
The notation f/4.0 is usually taken to mean the size of the opening left by the aperture blades is equal to the focal length divided by 4, so for a 400mm f/4.0 you'd expect to find a 100mm opening. So given the maximum size of the opening is clearly fixed, if your lens has a variable focal length you would expect f ratio to change as you zoom.
This is not quite correct however, f/4.0 only means that the image of the opening as seen through the front of the lens appears to be 100mm - if you look at the barrel of such a lens you'll see there's no space for a 100mm iris. In fact the aperture is smaller but is "magnified" by the lens elements.
So via clever (and expensive) optics its possible to make the aperture appear to get larger as you zoom, giving you a constant f number.
I have heard of a photographic effect known as the 'Orton Effect'.
Can anyone tell me what the effect is, what its history is and how I would create it in both film and on my digital SLR?
Answer
The Orton Effect is an image-processing technique resulting in a high-contrast look with a slightly "glowing" appearance. It started as an analogue technique made from two slide exposures of the same scene - one sharp and one soft - but nowadays it's more commonly done digitally. You can find plenty of examples on Flickr.
A basic recipe for doing this in Photoshop (or similar image-editing software) is as follows:
I am looking for apps for my mobile phone (Generalizing it to any mobile phone rather then being a specific Android, Apple or Windows phone) that I will find helpful while taking pictures on my DSLR.
For example I've an app that calculates the Depth of field given some parameters and another one that shows sunrise / sunset time and position.
I am not looking for apps that do creative stuff for pictures taken on the mobile camera itself.
Are there anymore apps around that could be considered as "must-have" for photographers?
This wikipedia article concerning focal-plane shutters opens with the following statement (bold emphasis added by myself):
In camera design, a focal-plane shutter (FPS) is a type of photographic shutter that is positioned immediately in front of the focal plane of the camera, that is, right in front of the photographic film or image sensor.
Other references concerned with photography almost universally seem to equate focal plane and film plane. This statement is from the wikipedia article concerning focal length (bold emphasis added by myself):
When a photographic lens is set to "infinity", its rear nodal point is separated from the sensor or film, at the focal plane, by the lens's focal length. Objects far away from the camera then produce sharp images on the sensor or film, which is also at the image plane.
In both of these references the meaning of focal plane and image plane appear to be interchangeable when the distance from the lens' rear nodal point to the film/sensor plane is equal to the lens' focal length.
Yet in physics references that discuss the field of optics (such as this wikipedia article linked from the article cited above) the focal plane is defined differently. It seems the front focus plane is defined as what photography refers to as the plane of focus. The back focus plane seems to be defined as the point behind the lens where the aperture is ideally situated. Yet the charts and diagrams on the same page seem at times to use the terms rear focal plane, back focal plane, and image plane interchangeably. Sometimes it seems they are referring to the plane where the image is brought into focus (such as this diagram and the text beneath it in the article). At other times it seems to be referring to the crossover point between the lens and the image plane (such as this diagram and the text next to it in the article).
When speaking in the context of Photography that uses film or a digital sensor to record an image projected onto that film or image sensor is it legitimate to refer to the film or sensor as occupying the Focal Plane? Is there a nomenclature that allows one to distinguish between the plane occupied by the objects depicted as in focus in the image (plane of focus?, front focal plane?) and the plane the in-focus image is projected on (rear focal plane)?
Answer
EDIT: I have studied the focal plane vs. image plane issue more. The description below the === line is true in optics, and sometimes in specialized photography.
In generic use,
Notice also the two definitions here.
=====================================================
Let me walk you through the focal plane and image plane definition in optics (!!), where these are two distinct planes.
Let's start with: http://upload.wikimedia.org/wikipedia/commons/thumb/e/e3/Cardinal-points-1.svg/500px-Cardinal-points-1.svg.png
You can see two focus points, F and F'. The function of those: if you emit light from either, let's say F', you will see parallel light rays on the other side of the lens. Conversely, an object that is infinitely far away, will emit rays that are parallel and all those will go through point F'. Now, that's great. Why? Because all those rays go through a concentrated, small space, so you can put a focal-plane shutter there, you can control aperture using a diaphragm , and since all rays go through that point F', you do not have to worry about how big lens you have (maybe 77 mm? maybe 1 m?), it is very easy to let rays pass through there or stop them from propagating.
Okay, so that is point F'. You use only one of the focal points, obviously, so you do not care about F.
A focal plane is just the plane that is perpendicular to the optical axis of the lens, and it goes through point F'. You basically put the diaphragm, the focal-point shutter directly in the focal plane.
Please note:
(see animation - sometimes just a static image...)
The film or sensor is in the image plane. This is NOT the focal plane at all in optics.
If you put the film or sensor in the focal plane, you would ideally have a single tiny white spot on the sensor. Since the lens is not ideal, you would see a very blurred small spot, that's all.
Now, I hope this is all clear, sorry for my English.
If you understood and agreed with what I wrote, here is another link: http://en.wikipedia.org/wiki/File:BackFocalPlane.svg
The rays going vertically from the "object" are the parallel rays. There are two red ones and the black axis. All these go through the intersection of the back focal plane and the optical axis (vertically, the symmetry axis).
If the object is not infinitely far away, you will see the other lines emanating from the object. Those go through the back focal plane, and you can see, they are close to the focal point, yet those light rays create a bright spot on the focal plane.
On the image plane, all rays, that depart from the same object point, arrive in the same image plane point. This is important: this is the requirement for an image to be in focus, to be sharp. (It is kind of obvious: if a point on an object created multiple image-points, e.g. a tip of a needle creates a big spot - then that is obviously out of focus).
I hope my description is clear.
I am making a research to buy my first full-frame camera and I have 2 options, one Canon and other Nikon. Talking about the comparison in-between the d800 and the 5d mark III for example, the low light performance seems to me an important subject. So, How can I make a technical review of this subject as opposite of the common trend to make this very subjective?
I know there have been a lot of posts on this topic, but I haven't found exactly what I am looking for.
I noticed some dust spots on my sensor for my D750 after I took a picture with some sky in it and then was playing around with "dehaze" in Lightroom. Okay no problem, I have owned the camera for a year probably time to clean the sensor.
So I do a bit of research online and land on the fact that I can do this myself. I also want to learn how so I don't need to spend $50 or $75 each time I need this done. I decide to buy this kit.
What I do is close my aperture down to F22, put my ISO on 100 and then set my shutter speed to 2 seconds or so and take a picture of a well lit white piece of paper.
I then go into Lightroom and jack the dehaze and look for dust spots. I see a ton. Okay, so now let's clean it. I wet the swab with a few drops to get it just saturated on the top of the swab, apply some pressure, wipe left to right, turn it over, wipe right to left and done.
Then I took the same picture and although the dust spots are different, they are still there! What the heck? Okay maybe it just needs a good blow out. I took my rocket blower and blow out everything I can inside of there, then I do the same cleaning method as the first time, except this time I start with a dry swab, throw it out, then get a new swab, wet it and clean it again.
I take the picture again... and they are STILL THERE. Okay let's get out the high power flashlight. I wouldn't say I scrubbed it, but I went back and forth with the swab on what seemed to be a stubborn spot (I know, sketchy). Then I clean it again with a normal swab and take another picture.
This went on and on and I have basically ran out of swabs. I still see spots. I used the same swab a few times (I know, also sketchy) because I just couldn't figure out why it wasn't getting clean. I even tried a can of air (although some don't recommend that because they have solvent in them, but I was desperate and some people on youtube did it). That actually seemed to help, but in the end I still have spots.
So obviously a lot of you will tell me to just "take it in! you're going to break your sensor", but I really want to learn how to do this. And now I am just stubborn.
The spots are at the top and bottom of the frame mostly.
Any ideas? I ordered this gel stick today, and I was going to try it out very carefully. I also ordered more swabs.
Photos of the sky F22, ISO-100, 1 second
EDIT: I tried the gel stick. It did seem to help, but on the second try something else got on the sensor so I am going to wait until tomorrow to get the swabs and then try to do a swab cleaning + the gel stick again... we will see.
EDIT2: Well it looks better. I think the gel sticky stick helped but it's still not spotless. I ran over it one more time. I also included a photo above to the people are nervous about cleaning their own sensor. Obviously I can't guarantee you won't screw up, but I ran a swab over this sensor at least 15 times and it still shots great.
Answer
Unless you are working in a NASA grade "clean" room, no matter what method you use you will almost never get every single dust spot. Even if you do, by the time you put a lens back on the camera, more dust has probably made its way into the mirror box of your camera and some of it may eventually find its way onto the surface of the filter stack in front of the sensor. The front of the filter stack is what is cleaned when we use an air blower, swabs, etc. on our camera's 'sensor'. So the point of sensor cleaning is not so much to get a 'perfect', dust free result as much as it is to reduce the amount and influence of dust on your images to a minimum achievable level.
When I clean one of my sensors I take test images after each pass with a swab. After early attempts to get every single spot and going through several swabs, similar to what you relate in the question, I've learned to 'quit while ahead' even if there are still a few light dust spots remaining. The next pass at that point may well result in more dust spots showing than remained after the previous attempt.
Before I use the first swab, I'll often try several clean/test cycles with the air blower. If none of the spots are staying in the same location on the sensor, I won't even use a swab. I'll just continue to use an air blower until I get a test image that gives a result that reaches the level of 'as good as can be expected'.
Corners are always the most difficult to clean with a wet swab. It takes a bit of practice to learn how to use the edges of a swab to clear out each corner by slightly rotating the stem of the swab back and forth at the end of a pass. But based on my experience, doing it yourself will never result in a perfect result with zero dust. Based on the experience of others I've talked with, neither will dropping the camera off at a local camera store and paying them for cleaning the sensor.
I've never shipped a camera to a factory service center to have a sensor cleaned. Maybe some of them have methods that can get a near perfect result. The cleaner environment in which they work on cameras and lenses certainly can't hurt.
With our DSLR, indoor flowers come out detailed. Outdoor violet and blue flowers are detailed, too.
But outdoor bright red flowers give us problems. They come out as a single flat detail-less spot. Sometimes bright yellow flowers do this too.
Why? What we are doing wrong? Is it a camera defect?
In some of our pictures of red flowers, you can see small white reflections on the petals, but on other shots, the whole red flower appears flat, as one blob of same-color pixels, lifeless and volume-less. It is disturbing.
I am not asking how to to photoshop this image. The question is how to shoot correctly in the first place.
Condition: outdoor, sunlight, Nikon D5000, unresized, unprocessed jpeg.
Answer
So the other posts are correct in that the red channel is being blown, but what you really want to know is how to overcome the issue within the camera without post editing. The Nikon D5000 has the Picture Control System giving users the ability to customize image capture preferences. Six settings are available — Standard, Neutral, Vivid, Monochrome, Portrait, and Landscape, along with the ability to create up to nine custom Picture Control settings.
I shoot with a Nikon D300 and have EXACTLY the same problem as yourself. Normally I have my picture control set to Vivid as I shoot a lot of nature, landscape and macro so it's nice to have the colours punch through. However whenever I am then shooting red flowers I change the control to either Standard or Neutral so the red is not blown.
Personally I shoot all my images in RAW (NEF) format and this allows me to change the Picture Control in post (using Nikon's NX2 software) which means I can choose the end result utilizing a larger screen and also I don't have to change the camera configuration for a single image while out in the field.
There are additional Picture Control setups that you can download at http://nikonimglib.com/opc/ but I don not know if these are compatible with the D5000, they may be as it is possible to add up to nine custom Picture Controls.
Suppose you want to store your photos at some lower resolution, let's say about ~1 MB large.
You own a camera able to make photos at 5 MPix and more.
And, you want to have the maximum quality at the smaller size.
Would it be better to make a photo at highest resolution and then resize it with PC software (with a good filter of course), or to directly set the camera to make photos at 2 MPix only?
Answer
Downscaling a larger image on computer is almost certainly going to produce a better result. This is because resizing an image is very processor intensive, and there is a difference in quality between the various resampling algorithms (e.g. Lanczos vs Bicubic). Getting a 5 MP camera to produce a 2 MP image is going to cause the camera to perform the resizing and this is bad for 2 reasons: a) You can't control what resampling algorithm is used and b) The camera is always going to have a weaker processor than your computer so will inevitably use a resampling algorithm that's optimized for speed not quality.
So if quality is important, do your resizing on the computer.
I am going to be getting a Nikon D7000 soon. I think I'm correct in assuming that the Nikon D7000 will use its own focus motor for an AF lens, but allow the lens to use its motor for an AF-S lens. I'm looking at 50mm prime lenses that are AF and AF-S. From what I understand, AF-S lenses are a bit faster, and possibly more accurate (are they?) but is it worth the extra bump in money (~$85) to go with the the AF-S vs. the AF? How does this question change at other lengths (35mm, 80mm etc.)? Is the answer the same across the board? (If the AF-S simply performs better, I think it's worth the money.)
Does it make sense to go with AF-S lenses now just in case I move to a Nikon DSLR that doesn't have an internal motor?
Answer
Yes, yes, no, maybe, no, probably, no
PS: We recommend one question at a time.
I've just found an old disposable camera after a bit of a tidy up, no idea what's on it.
On the bottom it says develop by 08/2010 so it's about 6 months overdue.
Will the images still be OK to develop? I.e., does the film degrade after time? I am not looking for prints, just need photos onto disc.
I've been looking to upgrade my Mark III's kit lens, and am comparing lens strategies. The 70-200mm canon F2.8 seems like an enduring and very popular lens. After holding one, I am left wondering why?
My use case is for trips and general photography, so I'm today thinking about the 200mm prime, which is much lighter, and the 28-70mm which covers the mid-range.
Obviously you don't get the coverage, but these two lenses are much easier to carry and use. So is the 70-200 designed specifically for something like say, sports, or fast action distance events?
There are completely black corners in some of my photos. What can cause it?
I have a full-frame Canon 5D Mk II and had the problem with my 24-105 Canon lens recently and have experienced it with my 12-24 Sigma lens before.
Answer
Most likely an incorrectly oriented lens hood. Lens hoods for zoom lenses are petal shaped, with cutouts which are designed to avoid shading the corners. The largest bits of the petal should be top and bottom, if the hood is rotated it could be the corners of the image are being blocked by the hood.
It could be you're using a lens designed for a smaller sensor so the image circle doesn't illuminate a large enough area, leaving dark corners. Finally there could be something lose inside the lens which is causing mechanical vignetting.
The site already has a good example of what to consider in regards to camera and lenses around sand, but I specifically am wondering what considerations to make when using a tripod near sand. Many years ago I took a cheap tripod with lever style legs, and sand really wrecked the entire tripod. I am hoping this time to avoid that issue. Is there a style of tripod that might be better, and how can I use it in such a way to limit any long term damage?
I don't have any specific shots in mind, just likely some long exposure night shots of the beach resort, and I might get it out in the day time for some self portraits.
Answer
In addition to @Itai's answer, I'd like to add, if you don't want to spend 1200$ on a tripod just to protect it from sands, you can use a little care, or on extreme situations, alternative DIY methods.
I also wrecked a tripod (not totally wrecked, but the sands kind of jammed the levers on the legs) by using it near a beach on a windy day. The next time I took some plastic (polythene) bags, cut them into long pieces (3" width) and adhesive tapes to put them around the leg lever joints like bandages. Worked like a charm. The only problem is, once you tape them in, you lose the ability to adjust the tripod height by extending the legs, otherwise this is good enough if you're not planning to go all out beach shooting. Adjust the tripod height before applying the tapes and you're good to go for that day.
And after the shooting, get to a safe place and use a rocket blower to blow off any accidental remaining sand particles near the lever joints just to be on the safe side.
DISCLAIMER: This method doesn't look pretty.
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