It seems to me there must be some kind of error in color calibration of most cameras. They make shadows much darker than they are, and bright areas much brighter than they are. It's not from a lack of dynamic range.
Colour transparency film (e.g. Fuji Velvia -- RVP50) shows the same thing as clearly.
You basically can't map real world light into the dynamic range of a typical camera without causing some of this experience, can you?
The question is how you determine how dark shadows should be -- your brain is doing a lot of work to hide from you the tricks it uses to make shadows appear less dark than they might be with a linear response.
Or even how they would look with a non-linear response that is even across the "frame"; your brain is doing localised dodge/burn type work, constantly.
Camera manufacturers have "tastemakers" for this stuff on digital, just as film manufacturers used to have them for film.
It is different because it is obvious that shadows are darker than in reality while highlights are much brighter than in reality.
Any brain filtering would have to affect the photos as well, even if it was true.
No common image format uses linear response. It would explain this problem if cameras treat them as linear.
Maybe they should just make the cameras take physically correct colors, instead of relying on people, as the typical person will always choose extreme contrast that will make the camera unusable. (and can be easily increased in editing)
What is "brain filtering" and why would you think either film or digital can reproduce the same visual effect as our eyes see?
Our brain does a perceptual aggregation of multiple frames and inputs. This is not how cameras work.
Also "make cameras take physically correct colors" is impossible unless you're talking about spectral capture, which is orders if magnitudes more complex. If you're using just RGB photosites AND RGB displays, there is no such thing as physically correct colors. Everything will just be a mapping at best, with the best that color science experts can actually provide.
The one I was replying to talked about brain processing. Whatever it is doesn't need to and shouldn't be reproduced in photography as the protograph gets processed just like everything else when you look at it.
Reality --> eye --> "brain filter"
Reality --> photo --> eye -> "brain filter"
Cameras should only record the colors as accurately as possible. Or if you want to nitpick again, so that the photo stimulates the eye receptors identically to whatever was captured.
It's physically impossible for a photo to send the same photons into the eye as the original scene did - imagine taking a photo outdoors in sunlight and then viewing that photo indoors, the whitest possible parts of the photo will be literally orders of magnitude darker than the original scene. Similarly you can't reproduce the same colours because you don't have all of the colours available (e.g. there's no way a computer screen using RGB pixels can reproduce the precise wavelength that a sodium lamp gives out). Trying to reproduce the experience of viewing the original scene is the best we can do, and that requires not just physics but biology and psychology. You talk about "eye receptors", but the line where the eye ends and the brain begins is actually very fuzzy - ontogenically your eyes are part of your brain, and the signals passing from eyes to brain are already in a "compressed form" where e.g. a straight line is represented by a single nerve impulse.
they already do that to the best of our abilities.
Color is incredibly complex. It's easy to say "we should capture it as accurately as possible" but I don't think you fully comprehend the high complexity involved.
Your concept of matching eye receptors is wrong too. Color is perceptual and subjective. Your perception of color is based on your upbringing, your genetics, your environment, your own mental faculties, your mental state etc...
What is accurate? Your eyes see some spectral energy, your rods and cones convert those to signals, your brain then adds that into an aggregate set of information that it's constantly infilling and, most importantly, guessing about.
You can't guarantee that multiple people see color the same.
Now even if a camera could hypothetically capture an image accurately to the real world (IMHO only possible with a hypothetical full spectrum sensor), how would you store it? The second you convert it to RGB data it needs a perceptual conversion to the bit depth of the data format.
Now even if you have a file format that can efficiently represent this, you'd also need full spectrum displays so that we could beam that exact color to your retinas.
Color science is incredibly complex. You're trying to trivialize it into matching your own narrow perception of color.
If you have never done this before, I absolutely recommend -- while it is still possible to do this in a practical way -- getting a cheap film camera, getting hold of a proper incident light meter (like a Sekonic L-208 or L-308), and shooting some Fuji Velvia 50 or Provia 100F. Or if you can find it, some modern Ektachrome.
For example you might want to go to a beach or a park and shoot throughout the day on a bright day. Put people or objects in the foreground and then shoot them with either the light behind you or in front. Use the incident metering dome to meter the light
(you'll need to look this up, but the broad point of it is you stand in the same light as your subject and point the meter into the light, rather than at your subject)
Once you see what transparency film does in high-contrast situations I think you'll better understand what I'm trying to get across.
I don't think shadows are darker than in reality, but instead don't have their detail captured, or get swamped out by high black levels on screens or glare in the viewing environment. Also highlights get clipped at a much lower level than in reality (photographs of suns aren't eye-searing unlike the real thing).
> Any brain filtering would have to affect the photos as well, even if it was true.
Not when the dynamic range of reality is much greater than that of photographs, and your visual system is one of the best visual processors in existence. It’s like reducing a 24-bit image to 16-bit - the image is “good enough” to identify the subject, but it is quite lossy. Photography itself is a lossy process.
There's something off about the brightness sensitivity curves, if I can dial shadow controls way way up and salvage an otherwise botched, underexposed photo, why is it that I have to do so manually?
The dynamic range is clearly there. And we're not talking about such ridiculous values that the sensor noise becomes prominent.
You can do that correction in that situation because you've looked at the image, you know what it is meant to be, and you can decide on a set of adjustments that produce something that approximates what you want, perceptually.
But without truly extensive scene knowledge, cameras can't do that automatically, and they also can't know what information that is important to the photographer that they'd be affecting if they did.
Cameras have to try to ascertain what would be middle grey in a scene and then apply a general purpose tone curve to an image, but they do not know what is in the scene.
They can't even know for sure if the photo they are being asked to take is properly exposed by any absolute definition, in fact.
[I cut out a lot of this because I don't think it's going to be easy to complete the explanation here]
No, the problem is VERY OBVIOUSLY more severe than that. It's really as if the images were treated as linear, which they are not. (they use gamma correction)
This is also incorrect and trivializing of the color science. Images may use gamma correction, they may not. Trying to describe it in terms of gamma is like trying to describe food in terms of saltiness alone. You're ignoring tons of other factors.
gamma correction is compression, sacrificing data in regions where the eye is less sensitive for more precision in the sensitive ranges. images would look the same without it, you'd just be wasting bits encoding differences that the eye can't see
That is exactly what is happening when you lack dynamic range.
Say that your eye is sensitive from light intensity 0 to 100 in some units, but your camera sensor only handles 40 to 60. That means that everything under 40 will be mapped to black, and everything above 60 will be mapped to white.
No, that does not make any sense. That should result in 40, and everything darker resulting in 40, while 60 and everything brighter resulting in 60. But what you can see is that 40 results in 0, and 60 resulting in 100. That should never happen unless there is an error in processing.
Only the picture file format should limit what range you can save with any modern camera.
That of course depends on how you show it on the screen. You can of course show those part of the sensor that didn’t register anything (less than 40) as grey, and everything than saturated the sensor as a bit lighter grey. But people don’t tend to like the look of those pictures very much, and they definitely don’t look more natural than the conventional processing.
The main limitation isn’t the file format. The main limitation is the sensor. On the lower end, it is noise in different forms that overwhelm the very weak signal from dark areas. On the higher end, the sensors get saturated, that is, the semi-conductor bucket for the charges that is released by the photons get full.
And then the experience of the picture is of course limited by the medium that is used to display it. Even the best screens can’t show even a small fraction of the contrast that the eye experiences outdoors on a sunny day. And don’t mention printed media.
No it doesn't make sense. You should not be able to capture anything darker than 40, or brighter than 60 if you are limited to 40-60. (actually by the file format, not the sensor, sensors today have higher dynamic ranges than 8 bit sRGB) It should not turn 40 into 0 and 60 into 100.
In real life, a logarithmic brightness scale (which is how human perception works) goes from negative infinity (zero energy) to positive infinity (infinite energy) – excluding both endpoints. 0 is not the bottom, and 100 is not the top.
In real life, photographs are printed on paper. The brightness of light reflecting off paper depends not only on the colour of the paper, but on the brightness of the illumination. (Likewise, photographs displayed on a computer monitor depend on the screen's brightness.)
In real life, human brightness perception depends on the brightness of the environment. An LED can look bright in the dark and dim in sunlight, and range dim to medium to bright on a cloudy day without anyone really noticing that the clouds between them and the sun are thicker or thinner.
In real life, there is no 0. There is no 100. Your comment doesn't make any sense.
Right. Metering is even now with scene programs and AI still basically a complicated negotiation about establishing middle grey -- when there may be no perceptual middle grey in the scene at all (black cat in coal bin, polar bear in snow)
The narrow band of sensitivity of a film or sensor has to be sort of moved to where it is needed (by controlling how much light gets in or for how long) according to the result the photographer is likely to want from their photo.
Even the most basic of film dead-reckoning methods -- Sunny 16 -- relies on subjective input from the photographer:
It's trivial to take an image editor and any existing image that is as you describe, and adjust the black point to 40 "percent" and white to 60%. It won't look more correct or realistic at all.
It's not the the camera that lacks dynamic range. It's your screen.
There's a fundamental problem with photography: a scene can contain up to 20 EV of dynamic range. Your camera can capture up to 14 EV. But your screen or a print can only depict 5-10 EV.
So something has to give. The camera capture is usually fine, only excluding the brightest highlights like the sun itself, and the darkest shadows, both of which we don't expect to contain detail anyway. But mapping the rest into the (let's say) 8 EV of available dynamic range of the screen is a problem.
Film does it in two ways: it rolls of highlights and shadows smoothly, preserving mid-tone contrast while compressing (and desaturating) extreme tones. Secondly, chemical diffusion enhances local contrast, while reducing global contrast, a bit like the "clarity" slider in Lightroom.
Smart phone cameras do something similar, with HDR image fusion, local contrast, and tone mapping.
Which is why, ultimately, only an edited picture can represent the experience of viewing a natural scene. The full tonal range of the scene can not be displayed. We have to rely on a somewhat artificial compressed rendition instead. But that's not a fault of the camera, or even the screen. But simply the result of showing an emissive reality on an (assumed) reflective medium. To me, it's the same perceptual unreality as projecting a 3D scene onto a 2D medium.
To me, it's what makes photography (and visual arts in general) interesting. They don't show reality, but a depiction of reality. And in that crop, project, compress, lies interpretation and expression.
No that can't be what's happening. You would expect contrast to be lost, not increased, if that was the issue.
8bit sRGB can contain 11.6 f-stops of dynamic range, and it is no longer enough for modern screens.
There must be a longstanding bug somewhere. It would not be the first time it happened. There was a chroma decoding bug in almost all DVD players. A very similar issue to this, antialiasing in CGI used to be calculated without gamma, until GPUs got fast enough to use it and I suppose that someone started looking into why it performs worse than expected.
Colour transparency film (e.g. Fuji Velvia -- RVP50) shows the same thing as clearly.
You basically can't map real world light into the dynamic range of a typical camera without causing some of this experience, can you?
The question is how you determine how dark shadows should be -- your brain is doing a lot of work to hide from you the tricks it uses to make shadows appear less dark than they might be with a linear response.
Or even how they would look with a non-linear response that is even across the "frame"; your brain is doing localised dodge/burn type work, constantly.
Camera manufacturers have "tastemakers" for this stuff on digital, just as film manufacturers used to have them for film.