Luminous Landscape Forum
Raw & Post Processing, Printing => Colour Management => Topic started by: Frans Waterlander on September 13, 2016, 12:38:47 am
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As covered in another thread, I have maintained that editing in too dark a room will result in a tendency to tone down the image brightness, resulting in prints that are too dark and here is the proof. My digital darkroom lighting causes the viewing area on the right site of my monitor to be around 28-30 lux; on the left side it is around 5-7 lux. With the lighting off, it's 0 lux everywhere. I edited the same image with the lights on and off, using Curves to vary the midpoint, trying to make the image look as I remember it. The results in % brightness:
lights on lights off
average: 54% average: 49%
wall: 97% wall: 89%
sky: 82% sky 58%
tailgate: 72% tailgate: 47%
shadow: 12% shadow: 6%
The averages were obtained by selecting the whole image and using filter/blur/average.
This suggests that the room brightness at lower levels (below 32 lux) does indeed have a big impact on brightness perception and editing results.
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You may be right, I suppose, and those more knowledgeable than I will argue the point; but nobody with a vestige of scientific knowledge or training would describe a single-image trial, undertaken unsupervised by a man who already believed he knew what the result would be and so had a (perhaps unconscious) vested interest in the outcome being in accordance with his preconceptions as "proof".
Jeremy
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As covered in another thread, I have maintained that editing in too dark a room will result in a tendency to tone down the image brightness, resulting in prints that are too dark and here is the proof. My digital darkroom lighting causes the viewing area on the right site of my monitor to be around 28-30 lux; on the left side it is around 5-7 lux. With the lighting off, it's 0 lux everywhere. I edited the same image with the lights on and off, using Curves to vary the midpoint, trying to make the image look as I remember it. The results in % brightness:
lights on lights off
average: 54% average: 49%
wall: 97% wall: 89%
sky: 82% sky 58%
tailgate: 72% tailgate: 47%
shadow: 12% shadow: 6%
The averages were obtained by selecting the whole image and using filter/blur/average.
This suggests that the room brightness at lower levels (below 32 lux) does indeed have a big impact on brightness perception and editing results.
The missing element in this discussion is the relationship between monitor brightness and environmental brightness in terms of their impact on the predictability of your softproofing. They can offset each other or aggravate each other depending on how handled. Much has been written about this.
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As covered in another thread, I have maintained that editing in too dark a room will result in a tendency to tone down the image brightness, resulting in prints that are too dark and here is the proof.
That's certainly consistent with expected color appearance phenomena - specifically the Stevens Effect and Bartleson-Breneman Equations. (See Mark Fairchild's book, "Color Appearance Models", chapters 6.7 and 6.9).
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As covered in another thread, I have maintained that editing in too dark a room will result in a tendency to tone down the image brightness, resulting in prints that are too dark and here is the proof. My digital darkroom lighting causes the viewing area on the right site of my monitor to be around 28-30 lux; on the left side it is around 5-7 lux. With the lighting off, it's 0 lux everywhere. I edited the same image with the lights on and off, using Curves to vary the midpoint, trying to make the image look as I remember it. The results in % brightness:
lights on lights off
average: 54% average: 49%
wall: 97% wall: 89%
sky: 82% sky 58%
tailgate: 72% tailgate: 47%
shadow: 12% shadow: 6%
The averages were obtained by selecting the whole image and using filter/blur/average.
This suggests that the room brightness at lower levels (below 32 lux) does indeed have a big impact on brightness perception and editing results.
I agree completely with Jeremy (kikashi) above. As a working scientist at the largest university in Canada, the idea that this is a well thought out experiment and/or "proof" of anything is ridiculous...
If YOU are happy to print in a bright or dark room and are getting the results YOU are happy with, then just go ahead and edit and print away... The amount of time that has been spent arguing over this issue the past week or two is mind boggling...
MS
(Edit for typo)
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You may be right, I suppose, and those more knowledgeable than I will argue the point; but nobody with a vestige of scientific knowledge or training would describe a single-image trial, undertaken unsupervised by a man who already believed he knew what the result would be and so had a (perhaps unconscious) vested interest in the outcome being in accordance with his preconceptions as "proof".
Jeremy
Yep. This test is fairly meaningless as application for anyone else.
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A good example of how not to propose a sound testing methodology Frans, as other's have suggested.
BTW, what device did you use to measure the lux?
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As covered in another thread, I have maintained that editing in too dark a room will result in a tendency to tone down the image brightness, resulting in prints that are too dark and here is the proof. My digital darkroom lighting causes the viewing area on the right site of my monitor to be around 28-30 lux; on the left side it is around 5-7 lux. With the lighting off, it's 0 lux everywhere. I edited the same image with the lights on and off, using Curves to vary the midpoint, trying to make the image look as I remember it. The results in % brightness:
lights on lights off
average: 54% average: 49%
wall: 97% wall: 89%
sky: 82% sky 58%
tailgate: 72% tailgate: 47%
shadow: 12% shadow: 6%
The averages were obtained by selecting the whole image and using filter/blur/average.
This suggests that the room brightness at lower levels (below 32 lux) does indeed have a big impact on brightness perception and editing results.
What was the surround value (a specification of your editing space and a triplet in that space is sufficient), and how big was it compared to the image?
Jim
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That's certainly consistent with expected color appearance phenomena - specifically the Stevens Effect and Bartleson-Breneman Equations. (See Mark Fairchild's book, "Color Appearance Models", chapters 6.7 and 6.9).
I've got that book, the equations are out of my pay grade. But I do see this specifically on page 140: The Stevens effect indicates that as luminance levels increase, dark colors will appear darker and light colors will appear lighter. The Stevens effect can be demonstrated by viewing an image at high and low luminance levels.(Andrew Rodney:this image is or isn't an emissive display?) A B&W image is particularly effective for this demonstration. (Andrew Rodney: Fran's used the wrong kind of image to test). At low luminance levels (Andrew Rodney:undefined), the image will appear to have a rather low contrast (Andrew Rodney: Contrast or perceived brightness?). White areas will not appear very bright and, perhaps surprisingly, dark areas will not appear very dark. If the image is moved to a significantly higher level of illumination, white areas appear substantially brighter and dark areas appear darker.
Nowhere do I see anything that states or suggests editing images on an emissive display in a dim environment produces images or prints that are too dark.
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You may be right, I suppose, and those more knowledgeable than I will argue the point; but nobody with a vestige of scientific knowledge or training would describe a single-image trial, undertaken unsupervised by a man who already believed he knew what the result would be and so had a (perhaps unconscious) vested interest in the outcome being in accordance with his preconceptions as "proof".
Jeremy
I agree and would add that it can be very difficult once one has a theory about how something works to be really subjective. This can lead us human beings to embrace those theories that coincide with our own and reject automatically those that don't - this is not the same of course as purposely misleading for ones own ends.
I have edited and printed both in a very dark environment up to fairly bright and not observed this particular phenomena as long as print viewing illuminated adequately I have usually been happy with the print outcome. Just my subjective view of course
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I agree and would add that it can be very difficult once one has a theory about how something works to be really subjective.
Objective, I think!
Jeremy
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Objective, I think!
Jeremy
You are correct, that's what I meant. I think the error due to me being in the dark :)
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A good example of how not to propose a sound testing methodology Frans, as other's have suggested.
BTW, what device did you use to measure the lux?
Never claimed this to be a sound testing methodology, but it's my effort to test, with the gear I have, the idea that a dim editing environment has an impact on editing. I just didn't think that the impact of room brightness would cease to exist below a certain level. I tried this on many different images, not just the one I posted, and the results were similar. Yes, I'm well aware of possible biases, but I tried to be as objective as possible. If anyone has a better idea, I'm all ears. And maybe folks should run their own tests and see what happens.
The ambient light measurement function of SpectraView II with the SpectraSensor Pro was used to measure the lux values.
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Never claimed this to be a sound testing methodology, but it's my effort to test, with the gear I have, the idea that a dim editing environment has an impact on editing.
And your peers (if I can be so kind) have dismissed it. And no, you didn't prove your idea.
Yes, I'm well aware of possible biases, but I tried to be as objective as possible. If anyone has a better idea, I'm all ears.
Well for one, listen to the two color scientists and the ISO, referenced in the locked post, that dismiss your ideas based on their recommendations for ambient conditions! One stating a lux of 4!
The ambient light measurement function of SpectraView II with the SpectraSensor Pro was used to measure the lux values.
Of the room?
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Yes, of the room.
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Yes, of the room.
So you also missed SpectraView's recommendation for Lux that of course jives with the ISO (what do they know.....) :o :
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So you also missed SpectraView's recommendation for Lux that of course jives with the ISO (what do they know.....) :o :
Didn't miss that and my setup meets those recommendations. They don't imply or guarantee that within the ranges recommended there won't be an impact on brightness perception and editing.
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Didn't miss that and my setup meets those recommendations. They don't imply or guarantee that within the ranges recommended there won't be an impact on brightness perception and editing.
They don't suggest that, because there's zero evidence, that using an ambient light as low as 32 Lux, causes images to appear or print too dark. That's your flat earth theory of which there is still no proof. Actually just the opposite.
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They don't suggest that, because there's zero evidence, that using an ambient light as low as 32 Lux, causes images to appear or print too dark. That's your flat earth theory of which there is still no proof. Actually just the opposite.
My theory and testing seems to indicate otherwise.
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My theory and testing seems to indicate otherwise.
Only to you. As other's have correctly pointed out.
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Only to you. As other's have correctly pointed out.
So, did you actually run some tests?
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So, did you and others actually run some tests?
It's as much a waste of time as trying to get you to prove your concept. I've been editing in dim and sometimes totally dark conditions for years and years; no dark images, no dark prints. So years of experience plus the recommendation of the ISO, NEC and two esteemed color scientists reinforce there's nothing to test. It works and works just fine.
Maybe you need your vision checked.
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It's as much a waste of time as trying to get you to prove your concept. I've been editing in dim and sometimes totally dark conditions for years and years; no dark images, no dark prints. So years of experience plus the recommendation of the ISO, NEC and two esteemed color scientists reinforce there's nothing to test. It works and works just fine.
Maybe you need your vision checked.
I do get dark images when I switch off the lighting, as I have reported. So it seems to me I have some prove of concept.
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I do get dark images when I switch off the lighting, as I have reported. So it seems to me I have some prove of concept.
Again, only for you. So you know what? Use what works best for you, and consider getting your vision checked. Meanwhile, I'll stick with my decades of experience editing image and the recommendation of people who know far more about this subject than I do, and certainly you do. And no, there's not a lick of proof you've provided for others.
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I do get dark images when I switch off the lighting, as I have reported. So it seems to me I have some prove of concept.
With the test you have cited you have only proven the concept for you and that particular image. While I'm not necessarily disagreeing with your point, the test you cited has no validity beyond you, in your room with that print.
I will say this again, as I wade into waters that are way over my head, that the vast majority of this sort of discussion exposes a certain level of fetishism (on both sides of the argument) that probably has little to do with actual print outcomes.
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Here's an approach that eliminates most of the experimenter bias:
Frans could select a group of 5 photographs.
Then have another person unware of this discussion or hypothesis tweak them using only the midpoint in curves in both lighting conditions to best match what they recall the printed images appearing like and saving the results.
These could then be examined to determine whether the adjustments were as significant as Frans indicates from his experience.
It would be best to have more than one person do this. However, if the results are anywhere near the differences in the images Frans posted this process should easily demonstrate that.
In my experience there isn't much, if any, difference from editing in any ambient light so long as it is well below that of the display or proofing table. However, I don't have any experience working in near darkness. It would be an interesting experiment.
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Here's an approach that eliminates most of the experimenter bias:
Frans could select a group of 5 photographs.
Then have another person unware of this discussion or hypothesis tweak them using only the midpoint in curves in both lighting conditions to best match what they recall the printed images appearing like and saving the results.
These could then be examined to determine whether the adjustments were as significant as Frans indicates from his experience.
It would be best to have more than one person do this. However, if the results are anywhere near the differences in the images Frans posted this process should easily demonstrate that.
Good suggestions, I'd add a few and a caveat. The images should be carefully selected and scene referred so no subjective edits have been applied. They should contain differing amounts of highlights/whites in the mix along with darker tones. Ideally the group would be both men and women of differing ages to account for their quality of color vision. The caveat is this would take a good deal of effort and the person designing the tests, selecting the images and observing the process needs not be prejudiced and is willing to undertake the effort. IMHO, that eliminates Frans from the testing. ;D
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As covered in another thread, I have maintained that editing in too dark a room will result in a tendency to tone down the image brightness, resulting in prints that are too dark and here is the proof. My digital darkroom lighting causes the viewing area on the right site of my monitor to be around 28-30 lux; on the left side it is around 5-7 lux. With the lighting off, it's 0 lux everywhere. I edited the same image with the lights on and off, using Curves to vary the midpoint, trying to make the image look as I remember it. The results in % brightness:
lights on lights off
average: 54% average: 49%
wall: 97% wall: 89%
sky: 82% sky 58%
tailgate: 72% tailgate: 47%
shadow: 12% shadow: 6%
The averages were obtained by selecting the whole image and using filter/blur/average.
This suggests that the room brightness at lower levels (below 32 lux) does indeed have a big impact on brightness perception and editing results.
The state of adaptation of the viewer affects the way that the colors are perceived.
Take look at Hunt's Reproduction of Colour, 4th Edition, on page 56.
With no surround at all on the monitor, objects visible in the periphery of the monitor become, in effect, the surround, and thus affect the viewers adaptation and the way that colors are perceived. hus lighting levels will affect the surround.
However, soft proofing without a surround is not accurate unless your output will be displayed under conditions where the surround is the same as the room where the editing is done happens to be and the image appears to be self-luminous. Those conditions are so infrequently met and so unstable that soft proofing with a sizable surround on screen is really necessary. Under those conditions, with a light gray or brighter surround and a monitor white point of 80 cd/m2 or so, the difference between a dim room and a dark room should be minimal.
http://blog.kasson.com/?p=15602
Jim
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Good suggestions, I'd add a few and a caveat. The images should be carefully selected and scene referred so no subjective edits have been applied. They should contain differing amounts of highlights/whites in the mix along with darker tones. Ideally the group would be both men and women of differing ages to account for their quality of color vision. The caveat is this would take a good deal of effort and the person designing the tests, selecting the images and observing the process needs not be prejudiced and is willing to undertake the effort. IMHO, that eliminates Frans from the testing. ;D
That would be appropriate for a more thorough experiment. I was trying to keep it simple enough that Frans (or anyone else) could do a quick test. His adjusted example photos are very, very different so a simple test should counter his results easily. But if, in fact, this is a real phenomena then it won't take much to replicate and then a more complete test with different people like you suggest would be in order. That said, this strong of an effect should already have been noticed and studied long ago and I'm not aware of any such study. OTOH, I haven't researched it either so it might have been.
I'm inclined to chalk it up to confirmation bias but I could be wrong.
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I agree completely with Jeremy (kikashi) above. As a working scientist at the largest university in Canada, the idea that this is a well thought out experiment and/or "proof" of anything is ridiculous...
Seems a well enough thought out data point to me. In itself it doesn't prove anything, but it is certainly how one starts to investigate a phenomenon of interest.
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That said, this strong of an effect should already have been noticed and studied long ago and I'm not aware of any such study.
Right, plus those who are much smarter and understand this topic better than I have already provided their suggestion, specifically Karl Lang, =/- 4 Lux.
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The state of adaptation of the viewer affects the way that the colors are perceived.
Take look at Hunt's Reproduction of Colour, 4th Edition, on page 56.
With no surround at all on the monitor, objects visible in the periphery of the monitor become, in effect, the surround, and thus affect the viewers adaptation and the way that colors are perceived. hus lighting levels will affect the surround.
However, soft proofing without a surround is not accurate unless your output will be displayed under conditions where the surround is the same as the room where the editing is done happens to be and the image appears to be self-luminous. Those conditions are so infrequently met and so unstable that soft proofing with a sizable surround on screen is really necessary. Under those conditions, with a light gray or brighter surround and a monitor white point of 80 cd/m2 or so, the difference between a dim room and a dark room should be minimal.
http://blog.kasson.com/?p=15602
Jim
Interesting. Frans could well have run his test in Photoshop with no surround or white border. If so then ambient lighting affects perception much more. I have a CG318 which is rather large and do editing with a gray, background. I also edit the image with a matching white border "canvas" if I intend to print with a white border. Similarly my proofing environment backing is a neutral gray that roughly matches what I use in Photoshop.
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But I do see this specifically on page 140: The Stevens effect indicates that as luminance levels increase, dark colors will appear darker and light colors will appear lighter. ]
Right. So when you are editing an image at low adapted luminance levels, you tend to compensate for the decreased contrast by reducing your darker colors, thereby increasing perceived contrast. i.e. you've reduced the overall brightness of your image.
But I prefer the elegance of the explanation in this paper: "A probabilistic explanation of brightness scaling" (http://www.pnas.org/content/99/22/14482.full.pdf), notably Figure 1. To summarize :- our local contrast sensitivity is highest around the brightness we are adapted to. Equivalently this makes the apparent brightness of anything above our adaptation level higher, and the apparent brightness of everything below our adaptation level lower. So at the extremes, if we are looking at an image with bright ambient light (say almost as bright as the white of the image), the whole image range will appear darker, while if were to have a very low ambient light level, the whole image will appear lighter. While editing we would compensate for this appearance, making the image brighter or darker respectively.
And as I've noted previously, it's also well accepted in setting up video viewing environments that the gamma of the display should be increased as the viewing environment gets darker. What this is actually doing is applying a viewing conditions compensation due to the difference between the video encoding gamma (about 2.2) used for material captured in bright environments and the display gamma (somewhere between 2.2 for bright environments, 2.3 for dim, and 2.4 or even more for very dark environments).
Poynton (http://store.elsevier.com/Digital-Video-and-HD/Charles-Poynton/isbn-9780123919328/) covers this in some detail.
Now if the display is not compensated for this effect when we are editing, then we will tend to make this compensation ourselves, making the image darker in a dark viewing environment.
Nowhere do I see anything that states or suggests editing images on an emissive display in a dim environment produces images or prints that are too dark.
Seems pretty clear to me from the color scientific literature and experience in areas like Video, that this phenomena is quite plausible.
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Seems pretty clear to me from the color scientific literature and experience in areas like Video, that this phenomena is quite plausible.
Plausible? Lots of ideas are plausible. Explain if you can, the ISO spec, specifically for editing our images and their recommendation for ambient conditions on a computer display and the comments from Dr. Lang? Or the NEC recommendation that confirms what the ISO suggests. Again, where is there proof that low ambient light conditions surrounding our display result in dark images and dark prints? Who besides Frans recommends not using an ambient condition lower than the suggestions above? Cause and effect.
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One can over-complexify an issue till it all becomes totally counter-productive. Why work in a totally darkened room altogether? Very bad for one's eyesight and completely unnecessary. Why work in a bright room where the distraction from the monitor could be overwhelming - just silly. So work in a low-light environment. For example, I have two shaded lamps burning 60 watt bulbs ten feet away from the monitor (which does not face the lamps). It's fine. From there, look at four things: (1) is the monitor too bright relative to the environment so you adjust the prints too dark; (2) is the image surround for soft-proofing not too bright and not too dark, to roughly simulate average viewing conditions of the prints (unless you have other viewing conditions), (3) is your soft-proof set-up correctly and (4) when the print comes out of the printer and you examine it say under Solux illumination, does it satisfy - is it faithful enough to the softproof? If the answers are NO, YES, YES and YES, you're fine. Print away happily.
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Why work in a totally darkened room altogether? Very bad for one's eyesight and completely unnecessary.
From the two closed posts:
(Karl Lang*) writes in the Adobe PDF on setting up a digital darkroom:
With the light output levels of current display technology, an ambient light level of 4 lux is an optimal compromise. While a lower light level would provide better results, it’s impractical. You need to be able to walk around your environment. Above 16 lux, the room ambient will have a very significant effect on the dynamic range of the display.
We should note that Frans has never told us 'what's too low' or provided any metric that he feels is so low, we'll begin to or will produce dark images and prints. Based on what Karl writes, Frans range at best is 4 lux or less.
* http://www.lumita.com/information/
Karl Lang is a color scientist, engineer and the principle of Lumita, Inc. With 20 years experience in the digital imaging industry, Karl has designed, developed and brought to market numerous products. The Radius PressView SR & XL, ProSense, ColorMatch, Separation Lab, and the Sony Artisan Color Reference Display System are just a few of the integrated color imaging products he created. Karl has extensive experience developing integrated systems that include hardware, software, industrial design and optical components. Karl enjoys the challenges and complex problems presented when integrating advanced color management into user friendly systems. A hallmark of all Lumita creations is the simplification of color management and the reduction of complexity. “Color management should just work.”
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Explain if you can, the ISO spec, specifically for editing our images and their recommendation for ambient conditions on a computer display and the comments from Dr. Lang?
The existing approach to dealing with viewing condition effects is to control them. Things like ISO viewing conditions have been developed with certain expectations :- maximum brightness of the display, the viewing conditions implied by the image encoding profile, etc.
Given the relatively low display brightness assumed (typically 100 cd/m^2), and the bad effects glare have on image appearance, it's easy to understand an emphasis on minimizing ambient light levels, so the standards end up specifying quite low levels. So yes, I would be surprised if going from an ambient of 10% of maximum image brightness to 0% will have much effect (so I'm agreeing with you in these specific circumstances). But there is every reason to believe that going the other way will have an effect - that's why ISO specify a maximum ambient level!
i.e. if you have been editing images on a display that perhaps is not setup to ISO (brighter maximum, ambient above 10%) and you have been happy with your resulting prints, and then you turn all the lights off and edit in complete darkness, your prints are likely to be darker.
Again, where is there proof that low ambient light conditions surrounding our display result in dark images and dark prints?
I've pointed you in the direction of understanding - the rest rest up to you.
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The existing approach to dealing with viewing condition effects is to control them.
No argument.
Things like ISO viewing conditions have been developed with certain expectations :- maximum brightness of the display, the viewing conditions implied by the image encoding profile, etc.
Indeed. So you disagree with their suggestions for the ambient light conditions around the display?
Given the relatively low display brightness assumed (typically 100 cd/m^2), and the bad effects glare have on image appearance, it's easy to understand an emphasis on minimizing ambient light levels, so the standards end up specifying quite low levels. So yes, I would be surprised if going from an ambient of 10% of maximum image brightness to 0% will have much effect (so I'm agreeing with you in these specific circumstances). But there is every reason to believe that going the other way will have an effect - that's why ISO specify a maximum ambient level!
Yes it is easy to understand. What isn't easy to understand is Frans idea a too low setting, undefined by him results in images and prints that are too dark. Do they?
i.e. if you have been editing images on a display that perhaps is not setup to ISO (brighter maximum, ambient above 10%) and you have been happy with your resulting prints, and then you turn all the lights off and edit in complete darkness, your prints are likely to be darker.I've pointed you in the direction of understanding - the rest rest up to you.
Again, where's the evidence to support that a ambient light at 32 lux or below results in images that are too dark or prints too dark? It's a simple question. Where's the proof? Or the ISO, Karl and the other's suggesting low settings are wrong?
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I was having a think about the ISO viewing conditions in relationship to ambient light levels, and there is no reason to think that reducing ambient levels below 10% will have no effect - viewing conditions effects are a continuum after all. So this raises the question of why the ISO conditions are so loose as to be "10% or less", rather than a specific aim point ? I wondered if perhaps the effects of ambient light are so much worse at 10% or more, that they were content for the viewing conditions to be "somewhere under" this range.
Rather than attempt to carry out psycho-visual experiments that have been done more expertly by others, I'm happy to simply make use of their work by using the CIECAM02 appearance model as a basis for investigations.
If I take (say) an sRGB ICC profile and run (say) 50% RGB values through it while varying the ambient light level, I get the following J appearance values (analogous to L* values):
Ambient % J Delta J to 10%
0 51.9 +3.3
10 48.6 0
20 43.0 -5.6
50 37.4 -11.2
100 29.6 -19.0
[ This was with zero glare, standard 20% image surround, and 100 cd/m^2 white. ]
So:
1) As expected, the image looks brighter as you reduce ambient levels.
2) There is a change if ISO 10 % ambient is reduced to zero.
3) But this change is a bit smaller than differences amongst higher ambient light levels.
4) ISO spec's are looser than they really should be for critical work.
If I then feed the 0% ambient J values back through the sRGB profile with the 10% ambient conditions, I get RGB values of about 53.5%, indicating that to (roughly) make the image edited at 0% ambient the same brightness as the one edited at 10%, one would have to increase the RGB values by about 3.5%. This is consistent with the numbers Frans Waterlander reported in his experiment, where his averages changed by 5%.
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I was having a think about the ISO viewing conditions in relationship to ambient light levels, and there is no reason to think that reducing ambient levels below 10% will have no effect - viewing conditions effects are a continuum after all.
No one is arguing that isn't true. Where does the ISO speak of editing images per se and do not recommend a low ambient light level when the print isn't being viewed? And further doing so results in images and prints (then viewed properly) that are too dark? Further, there is at least one authority and color scientist who does define specific recommendations for this task; editing our images:
https://www.adobe.com/digitalimag/pdfs/calibrating_digital_darkroom.pdf (https://www.adobe.com/digitalimag/pdfs/calibrating_digital_darkroom.pdf)
Specifically the recommendation is below 16 lux and as low as 4 lux (lower could result in bumping into things).
I think we must both agree with Karl that any ambient light striking the display affects the black and our perception of that display. High values, values not recommended make sense. Lower? Still no proof of concept.
Where are the masses of people who perhaps followed Karl's advise (this is an Adobe PDF that's been around awhile), complaining their prints are too dark while admitting they are working in conditions under 16 Lux or there about?
I suggest we must consider psycho-visual experiments, this is much to do about perception!
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I'll make one more comment and I probably have to move on (I'm being asked politely to do so).
The one person who's suggested a sound methodology thus far is Doug. Setup the environment with proper control to test various levels of ambient light. Control the surrounding, and placement of the lights (one can easily sabotage the results by pointing a light striking the display, use a hood etc). Start with a couple well controlled reference images. Specify (or not?) the edits that each person should apply. Get a good cross section of users. You can have someone with the best color perception on the planet who hasn’t a clue how to edit an image, ruin the experiment!. Consider that it is critical to involve human perception! Soft proof Make prints. Properly.
I'll also point out that people who report 'my prints are too dark' very, very often find, they are not too dark. They appear too dark compared to the display. Sure, some people do produce dark prints. That shouldn't ever happen with a color reference image (for example, the Roman 16s). Are the prints too dark or not? IF we agree that most often, they are not, there is a visual disconnect between viewing the print next to the display (which involves all kinds of variables, adapting to reflective/emissive output, etc), I can't see how we can disagree this test must include what people perceive. Where is the data that users report their prints are too dark in dark conditions? The other end of the scale, there's a huge number of users all over the net who report this, even to this day.
Is the experiment going to involve Soft Proofing? It should. What RI? BPC? What's the quality of the profile? Where do you see Frans stating his test was conducted with soft proofing on or the results were a dark print?
There's a ton of variables here. And Doug started providing a methodology to prove or disprove what Frans already believes.
Based on the ISO, based on Dr. Lang, based on 20+years of editing in dark conditions and setting up digital darkrooms for clients, I see nothing to indicate that editing in a dark room (again, undefined) results in images and prints that are too dark. For me, for my customers and it seems, a group posting here.
I'll leave it at that. Before I get locked out.
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And why would this thread be locked? Because people have opinions that differ and they discuss the issues? Come on! If we all stay civil here then I can't think of any reason why this thread would be locked.
I agree with GWGill's point that viewing conditions effects are a continuum. In my opinion, the ambient brightness should roughly match the monitor brightness; that way the ambient serves as a anchor or reference point for our eyes and this will reduce the tendency to turn up the image brightness under bright ambient conditions and turn down the image brightness under dim ambient conditions. How do you achieve this brightness match between ambient and monitor? In my case it's simple: I have two SoLux lights hanging from the ceiling to the right of my hooded monitor in line with the plane of the monitor screen, so no light falls on the monitor screen. There is a good brightness match between the monitor and prints viewed in this light (as it should be). These lights illuminate the general area to the right of the monitor, not just the prints, so I have my reference ambient at about the same brightness when I leave my SoLux lights on while editing. This works like a charm for me and I suspect it would work well for many others. If you have a viewing booth that doesn't illuminate the ambient much, then I would propose to put some image or material with average toanlity in the booth and leave it on during editing.
Why don't we here complaints from many people on this issue? I guess they either have a reasonable match between monitor and ambient, they have learned to live with the handicap or they waste paper, ink and time with trial and error. I don't put much value on recommendations for ambient values that vary all over the place (<32 lux, <16 lux, 4 lux). Those values may or may not work, depending on the monitor settings and how well people have learned to live with the problem.
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And why would this thread be locked? Because people have opinions that differ and they discuss the issues? Come on! If we all stay civil here then I can't think of any reason why this thread would be locked.
I agree with GWGill's point that viewing conditions effects are a continuum. In my opinion, the ambient brightness should roughly match the monitor brightness; that way the ambient serves as a anchor or reference point for our eyes and this will reduce the tendency to turn up the image brightness under bright ambient conditions and turn down the image brightness under dim ambient conditions.
I don't think operating where many visible objects in a room are at a luminance equal or above the monitor is a good idea. One white adapts to the brightest objects around and you want that to be the monitor. I like to run with a Photoshop neutral backing set to L=70 but it is still brighter than most everything else in my field of view.
There is an interesting point that hasn't been brought up. Ambient room light is illuminance. This is the light hitting a surface and is measured in Lux. Luminance is the light being reflected from a surface and is measured in cd/m^2. This is what your eyes actually see, not Lux. A perfect, reflecting (white, not mirror) surface will reflect Lux/Pi cd/m^2. For example, in a proofing booth with 500 Lux of illumination the measured cd/m^2 from the surface of a blank, Baryta print paper is about .92*Lux/Pi which is about 146 cd/m^2. If your monitor is set to 160 cd/m^2 this is very close to what soft proofing pure white on Baryta using "show paper white" will produce.
Now most people, including me, do not run their monitors at 160 cd/m^2 nor do they run soft proofing at 500 Lux even if those are recommended in graphic arts. I run a bit over 300 Lux for proofing and 100 cd/m^2 for the monitor. My room light runs around 3000K and Lux values depend entirely on where, and with what orientation I measure it. I don't really consider it very important except that I want the Lux that illuminates my monitor to be low enough that any reflected light is below .25 cd/m^2. It turns out that almost all the reflected light is around a 20 degree axis to the screen and roughly 2% of that is reflected back. Outside of that there is virtually no light reflected back. I can illuminate the screen with 200 Lux at an angle of 45 degrees and yet measure a luminance increase of only about .1 cd/m^2. But light coming from my direction is critical and gets reflected back hence I wear a dark or black shirt to reduce light reflected from me. So what matters to me is not directly the ambient but the luminance from reflected ambient and that is dependent on both the intensity and the angle. If the angle is more than about 20 degrees from max. reflectance it doesn't affect what I see on the screen.
Other than that both the monitor's white point and the neutral surround I use (I have a 30" monitor and just use the display to provide a surround) has a luminance significantly greater than the luminance off most objects in my general viewing range. I find this is necessary so that I properly white adapt. If I have particularly deep shadows I want to look closely at I'll drop the surround way down and turn the lights off if necessary but I don't edit with the lights off.
How do you achieve this brightness match between ambient and monitor? In my case it's simple: I have two SoLux lights hanging from the ceiling to the right of my hooded monitor in line with the plane of the monitor screen, so no light falls on the monitor screen. There is a good brightness match between the monitor and prints viewed in this light (as it should be). These lights illuminate the general area to the right of the monitor, not just the prints, so I have my reference ambient at about the same brightness when I leave my SoLux lights on while editing. This works like a charm for me and I suspect it would work well for many others. If you have a viewing booth that doesn't illuminate the ambient much, then I would propose to put some image or material with average toanlity in the booth and leave it on during editing.
Why don't we here complaints from many people on this issue? I guess they either have a reasonable match between monitor and ambient, they have learned to live with the handicap or they waste paper, ink and time with trial and error. I don't put much value on recommendations for ambient values that vary all over the place (<32 lux, <16 lux, 4 lux). Those values may or may not work, depending on the monitor settings and how well people have learned to live with the problem.
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I don't think operating where many visible objects in a room are at a luminance equal or above the monitor is a good idea. One white adapts to the brightest objects around and you want that to be the monitor. I like to run with a Photoshop neutral backing set to L=70 but it is still brighter than most everything else in my field of view.
I think there is a difference between the recommendations for a normal office work environment, and a critical viewing environment. For the former (going by ASA and personal experince), the general recommendation is to have a similar level of light for both paper documents and electronic displays, to minimize visual fatigue. Arranging things so that the illumination used for documents minimizes display glare is the trick. Electronic displays originated in CRT technology days, and inherited a lot of the assumptions that go along with Television - and television standards assume a viewing environment that is quite dim (2.2 gamma image encoding, CRT 2.4 gama native response). Things like ISO recommendations seem to follow the TV lead, with minimization of glare being one motivating factor.
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I agree with GWGill's point that viewing conditions effects are a continuum.
As I do and have said so. As does the ISO, both Karl's (both color scientists) referenced in other posts. Stay on topic! You have a theory that editing in a room that is too dim (undefined by you), results in images that are too dark and prints that are too dark. You tried rather poorly to prove this in the first post here. You were soundly and unanimously shot down. Read (re-read?) posts #2,3,5,6,10,16 and 25, in this thread alone. Note your lack of an answer to back up your theory in post #25. So in terms of peer review, you've moved nowhere. Doug and I have provided a few posts suggesting how you might begin to prove your theory. I suggest you get to work.
You have a couple options.
- Continue writing OT; not concentrating on the dismissal of your ideas presented here that so many have with your first post attempting to back up your theory. Hopefully we'll all move on and ignore this tactic.
- Take the suggestions of your peers and come up with a sound, scientific, unbiased testing protocol and present your actual data to your peers. Post #1 didn't cut it.
- Stop stating that editing in a dim room results in dark image and prints. You will not get called out and shown the work of others like the two Karl's, the ISO, the SpectraView software that do not back that up, just the opposite.
- Continue to state editing in a dim room results in dark images and prints, continue to be called out to prove your theory.
What's a bit telling is Frans deleted his original text in the original thread http://forum.luminous-landscape.com/index.php?topic=113202.0 (http://forum.luminous-landscape.com/index.php?topic=113202.0) :
Quote from: Frans Waterlander on August 31, 2016, 02:53:58 PM
I take issue with Andrew's statement that you can't have too little ambient light.
He wasn't able to delete our replies with that text!
Let us examine your very own text that started us down this rabbit hole that wasn't deleted by you:
Care to explain how, in a room that's too dark, you won't edit your images to be too dark, Andrew?
Care to explain using sound testing methodology it will? That hasn't occurred.
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Why don't we here complaints from many people on this issue? I guess they either have a reasonable match between monitor and ambient, they have learned to live with the handicap or they waste paper, ink and time with trial and error.
Just assumptions on your part.
I don't put much value on recommendations for ambient values that vary all over the place (<32 lux, <16 lux, 4 lux).
It's clear you don't. What is also clear is you can't prove why others should agree with your recommendations or lack thereof! Yet the ISO and two color scientists referenced DO provide recommended values. None state anything about the results being prints or images that are too dark. Prove them wrong.
Those values may or may not work, depending on the monitor settings and how well people have learned to live with the problem.
Without data, you're just someone with an opinion.
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FWIW - my practical observations of a printer and a color geek are that:
- dark monitor background may open shadows slightly (Bartleson-Breneman effect),
- ...but working in bright environment is even worse due to excessive monitor contrast decrease
As a result I ended up working in dark environment with highlighted monitor background:
(https://dl.dropboxusercontent.com/u/19059944/Spectrino2.jpg)
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So, Andrew, we agree that viewing condition effects are a continuum. As the ambient becomes lighter, the image will appear darker, resulting in a tendency to brighten the image during editing; as the ambient becomes darker, the image will appear lighter, resulting in the tendency to darken the image during editing. My test images appear to confirm this. So where is the sweet spot? I suggest that the sweet spot is where the ambient brightness is not higher or lower but equal to the monitor brightness.
Brightness balancing is an important part of fine-tuning the monitor and print viewing set-up so the image on the screen and the print match. So, I suggest that the print viewing set-up is the ideal ambient for image viewing and editing on the monitor. I further suggest that the print viewing setup be placed right next to the monitor to act as the reference point or anchor point for our eyes.
If the print viewing set-up is a viewing booth, then it should be placed next to the monitor set back enough to avoid booth light to fall on the monitor screen and be left on during all editing. The booth should illuminate a print with average tonality or an 18% gray card.
If prints are viewed with e.g. SoLux lights, then I suggest those lights shine down and are set back to avoid illuminating the monitor screen. They should be on during editing. If you have a stand for prints, then put an average tonality print or 18% gray card on it. If you don't have a stand for prints, but handhold them during viewing, then the area that is lit by the lights acts as your ambient.
The use of a monitor hood is of course essential. The rest of the room should be as dark as possible to minimize reflections in the monitor screen.
Another way to create a reference ambient is to use a large 18% gray area around you images on screen. The danger in this approach is that you will want to view your images at larger magnifications and compromise your reference ambient
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Another way to create a reference ambient is to use a large 18% gray area around you images on screen. The danger in this approach is that you will want to view your images at larger magnifications and compromise your reference ambient
Note that in Viewing Conditions speak, "surround" is not the same as "ambient":
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Just a thought but it seems to be that this effect, to the extent it's real, should be the same with prints. Prints made with images with what amounts to a gamma adjustment based on working in a dark v well lighted room should also look properly adjusted when viewed against a black wall and a lighted wall. So perhaps a test could be done with sets of prints and having people choose which looked better against black paper and against white.
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So, Andrew, we agree that viewing condition effects are a continuum. As the ambient becomes lighter, the image will appear darker, resulting in a tendency to brighten the image during editing; as the ambient becomes darker, the image will appear lighter, resulting in the tendency to darken the image during editing. My test images appear to confirm this.
We don't agree, you've provided no proof, and I'm out of here.
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We don't agree, you've provided no proof, and I'm out of here.
For the record:
Reply #38, GWGill: "...and there is no reason to think that reducing ambient levels below 10% will have no effect - viewing conditions effects are a continuum after all."
Reply #41, Frans: "I agree with GWGill's point that viewing conditions effects are a continuum."
Reply #44, Andrew: "As I do and have said so."
Reply #47, Frans: "So, Andrew, we agree that viewing condition effects are a continuum."
Reply #50, Andrew: "We don't agree."
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We don't agree, you've provided no proof, and I'm out of here.
I've provided a couple of posts supporting the proposition with established color science, while you have made no attempt to disprove it. This leaves one with the impression that like any good conspiracy theorist, no amount of proof will convince you.