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  #51  
Old 02-15-2019, 09:30 PM
mhendo is offline
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Originally Posted by Hermitian View Post
But we can't stop there and lay it all at the feet of the camera makers. The photography lighting would be different, the default photo background color would be different. Everything involved would be slightly different to make photographing darker skin tones better. Can that be done, yep (as mentioned before, you can if you are a cinematographer who can control every variable). Is it easily or quickly done? Probably not.
Right.

It seems that, at least in terms of the overall question about optimizing the camera, one of the OP's biggest failings is an apparent misunderstanding of how exposure and lighting are actually dealt with by the camera's metering system, and expressed in the subsequent exposure. There seems to be an assumption that you can just make some corrections regarding how the camera deals with skin tones, and everything else will remain the same, but that's not how exposure works.

While cameras are getting increasingly sophisticated in their ability to deal with varying light conditions, especially contrast, if there's one thing that I have come to appreciate as a photographer, it's not the technology in the cameras; it's the incredible ability of the human eye/brain combination to deal with a massive variety of lighting conditions. We can look at a scene with bright sunlight, deep shadows, different colors, and different lighting sources, and as we look around the scene our eyes and our brains make tiny, almost instantaneous adjustments (some of them mere inferences based on past experience) in order to take in and comprehend as much of the scene as possible. This is especially true for lighting-related issues such as the color temperature of the light sources, and the dynamic range of the scene. We can "see" the warmer light of a tungsten bulb, but we correct for it automatically. We can see that the deep shadow is much much darker than the bright sunlight, but when we look at the shadow we automatically adjust to take in the details.

Cameras don't quite work like this, or at least not with such incredible speed and detail. For all of the massive improvements in camera technology, the fact is that, when you press the shutter, you have to reduce the whole scene to some sort of average or ideal value. You aren't really able to make adjustments within the scene, at least not when to take the picture; you are recording it with a single aperture and a single shutter speed, which means that many areas of the scene will not be rendered in a way that resembles what you see with the naked eye.

This doesn't mean that everything looks bad. One area where digital photography has improved immensely over the last decade or so is in that area of dynamic range. What this essentially means is the amount of lighting range, from bright highlights to dark shadows, that the camera's sensor is able to capture while still preserving enough detail for later adjustment. For example, Nikon's last DSLR, the D850, has a dynamic range of about 14 Exposure Value (EV), or 14 "f-stops" of light. Each EV or f-stop doubles (or halves, depending on the direction) the amount of light. So if your scene has a range of 14 EV, it means that the lightest part of the scene is 214 times as bright as the dimmest part. That's a range of about 16,000 to 1.

But while a modern camera like the D850 might be able to photograph a scene with a dynamic range of 14 EV, it won't render all parts of that scene as the eye sees them. What the excellent dynamic range means is that, when the photographer puts the digital picture file onto the computer, he or she can then use software like Lightroom to process the picture, bringing up detail in the shadows and bringing down the highlights, or whatever is neceesary to render the scene in the desired way. It's worth noting that this works far, far better if you use the RAW files from the camera, rather than the JPEGs. The RAW files record the data as it hits the sensor, leaving as much data as possible and allowing a much greater ability to process the image in a wide variety of ways.

Of course, the OP was asking about cameras, but was also asking specifically about ID photos. This changes things in a couple of ways: on the one hand, the cameras used for ID photos are often much less sophisticated than the D850; on the other hand, the specific photographic conditions for ID photos are generally much more consistent and straightforward than a typical scene. As bump notes, above, it would probably be relatively easy to set up an ID camera system to expose various types of skin tones pretty consistently and accurately.
  #52  
Old 02-15-2019, 11:17 PM
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The ID/lisence photo cameras are likely lowest-bid contractor-quality hardware, poor lighting, and an almost entirely untrained employee taking the photo as quicky and indifferently as possible. And--something not mentioned yet--the printer for the photo is probably built with speed and throughput prioritized over quality, too. Nobody in a "stand the person against a nearby wall, click a button and say 'next!'" setting is going to have the skill, equipment, or time of a professional studio photographer.
  #53  
Old 02-15-2019, 11:31 PM
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I should note, by the way, that ID photos don't just get dark-skinned people wrong.

For quite a while, until we had new pictures taken for new licenses, my wife and I (both of us pasty Anglos) had our skin tones very poorly reproduced on our California drivers licenses. My wife's face had an odd green-tinted cast to it, and my face had an orange hue just a bit lighter than one of Willy Wonka's Oompa-Loompas.
  #54  
Old 02-17-2019, 02:40 PM
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Quote:
Originally Posted by Quartz View Post
I watched that video. It ignores the simplest explanation: money. They were selling to people taking photos of white people. Note that when there was demand for films which worked well with black subjects they produced films that worked well with black subjects.
Which film was that? I never saw any color film that claimed better results for different races. Since two of the biggest film makers were in Japan, did they have export versions of their films? I found that film bought in Japan was fine for all faces of all races, subject to getting the exposure right.

Regarding black faces, I have seen reports that the face recognition software generally used is not as accurate with black faces. Is it the skin tone, or the facial geometry? AFAIK, the programs work on the latter. And the Chinese have systems that work just fine in the PRC, so perhaps there is some tweaking for a particular race.
  #55  
Old 02-17-2019, 11:09 PM
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I'm not pastie by any means, my normal skin tone is a bit like a white person who tans a little and almost got sunburnt yesterday.

Yet most of my IDs I'm either completely washed out so there's no face there or I look like George hamilton.
  #56  
Old 02-19-2019, 09:58 AM
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I think that ultimately VERY few people get a good looking drivers' licence or ID picture. Most are either underexposed or underexposed.

I think a lot of it is that the cameras are cheap and idiot-proof, and intended to be fast rather than accurate. It's been most of a decade since my last driver's license photo, but I remember it being basically "Go stand on that line- look here (points at some target on the camera) and smile!" I ended up kind of underexposed, and I'm super-white.

That said, when I got my latest work badge, they used what looks like a webcam to take my photo, and it looks fine. And so do all my black co-workers' badge pictures. I suspect that the Texas DMV camera back in 2009 was probably the model they bought when they first switched to digital photos and was just old and crappy.
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