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 p.3 #14 · Utility of dynamic range beyond a certain point | |
dmcphoto wrote:
Scotopic vision occurs in dark environments with luminance less than 0.001 lux, when only the rods in the retina are responsible for vision. Rods are not sensitive to color, so vision in the scotopic range is monochromatic. Starlight, (outdoors away from artificial light sources on a clear night with no moon) produces a luminance of about 0.001 lux. The scotopic range is where our eyes have their greatest dynamic range; about 20 stops for a contrast ratio of about 1,000,000:1. That's enormous, but it is monochromatic.
Thanks for that post.
The quoted section above relates to another way that photographic “seeing” is not like our visual system’s seeing.
This was brought home to me — yet again — with some of the aurora photographs of the past few years and, to some extent, some of the Milky Way photographs that have become such a “thing.”
I photographed a strong aurora from a location in northern California a year or two ago. The actual aurora was so marginally visible to my eyes that I was not even certain that I was seeing it. But if I aimed my iPhone at the sky there was very visible color. (Though still somewhat subtle in my location.) This is, at least in part, due to the loss of color sensitively at very low light levels in our vision… and the fact the digital sensors don’t react that way.
We see something similar in other kinds of photographs where the light is very dim… and the camera ends up recording something that has much more color than we saw.
I can’t say if this is a good thing or a bad thing — though sometimes I see some very unconvincing, overwrought night photography as a result. My own philosophy in my night photograph y is that I’m making photographs “of what the camera sees,” sometimes in situations where my eyes don’t see anything like the final photograph.
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chiron wrote:
And this is exactly what painters have been doing for thousands of years, going back to the cave paintings of Lascaux and of Altamira, and it is espcially relelvant for those of us who want the final expression of the image to be a photographic print.
Vermeer was able to create images of incredible beauty within a limited, compressed tonal range wherein one of the main sources of the beauty as well as the key subject of the painting was the light itself, which had to fit within the limited range. Much of what he did had to do with variations of tonal values within that limited range, combined with subtle color changes and gradations in the light as it moved across the room. As another painter said of Vermeer, he found a life's work in the corner of a room.
If anyone is interested in more about how he worked with light and color, there is an excellent web site called Essential Vermeer that can be found below. It contains a ton of information, so you have to look around it to find what you want.
Essential Vermeer...Show more →
Photographers can learn a LOT from painters and paintings!
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guidostow wrote:
For many decades, large format film photographers have been using the zone system and advanced development techniques to expand the dynamic range of their films to more effectively capture the tonal range of high contrast scenes. Increasing the dynamic range of sensors helps us achieve more in the digital realm.
In part, the zone system was designed and often used to try to ensure that the largest amount of important image data was captured on film. And, of course, for film things worked a bit differently. Example: The brightest image elements were recorded as the darkest tones on the negative, but because film’s response at the margins was not linear film photographers did not run into the same “hard stop” that we encounter when we blow out the highlights in digital exposure.
The issue was tricky (again with negatives)with the darkest tones. Today we worry about noise at the low luminosity levels — back then they had to worry about whether the film would even register sufficient detail since dark areas would be the lightest areas of the negative. The zone system helped ensure that scenes with lots of dark areas were not underexposed, but photoraphers resorted to all kinds of other “trickery” to make this work, too: pre-exposing negaitives so that there would be at least some density in the darkest areas of the scene, and varying the exposure and development process in all kinds of ways.
Today we do something that is not altogether different from what zone system film photographers did, though we have a bunch of advantages that make it easier. For example, when we look at a scene with a few specular highlights and decide to let them blow out (which can be just fine) in order to get better shadow detail, we are making a zone system style choice… as we are when we do the opposite to protect highlights and plan to bring back shadows in post.
A lot of us expose not for “the best” SOOC image but the file that holds the most usuable and important image data, with a plan to optimize that in post.
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It is still useful to continue to expand the dynamic range that cameras are capable of recording with good fidelity, but not for SOOC images — instead it is so that we, like film photographers and painters, can produce photographs that include elements that originally ranged from very dark to very light… by means of post-processing techniques.
Note: For those who might be thinking that they don’t want or need toe PP stuff and, for example, are happy to shoot jpgs… your CAMERA is doing some of that kind of processing for you in most cases. :-)
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Yeah, I admit it, I’m fascinated by this stuff… and I bring it to bear on my own photographs.
Edited on Jun 11, 2026 at 08:55 AM · View previous versions
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