http://www.luminous-landscape.com/reviews/two-displays.shtml

This is a strange article and I honstly don't understand what it is about.
An Eizo CG is better than an Apple Cinema Display. Well, yes...
Don't want to be nitpicking and let the rest pass without comment but I am interessted in a source for this quote: "The recommended brightness for photography is 80 cd/m2".
IMO this is pretty much dated. If any today the recommendation is 120cd/m2 (or 160cd/m2). But more serious recommendations always refer to the viewing conditions as the right brightness is the one that matches paper white (both brightness and white point) under the viewing (or "ambient") conditions you are working in.
In a black room only with a battery charger as "ambient" light a display at 80cd/m2 might be to bright. If you set up the display on a glacier and compare the softproof to the respective print... you won't see anything on the display and you will feel that the pirnt is too bright (or the other way around: that the display is too dark, what is definitely true under these conditions).
As to the "too dark prints" I claim it's mostly not the too high brightness but the too high contrast of the displays.

I would more go towardes the middle. No question if you set your display to 160 in normal photographic conditions you will be blind and you prints will look very dark. I think right now the best is around 100cd/m2. However it certainly depends on the room itself.

the 160cd/m2 translates to the standard brightness of a D50 viewing box (500 lx)... of course just as a reference point.
There is no "middle" - there is your room, your working conditions, and you have to take care that they stay constant.
If you are working under standardarized conditions you have to match the specs of the respective ISO. But even than you will fine tune your devices.

I think 80cdm^2 was a recommendation for CRT's, because many of them couldn't go much brighter than that anyways, especially if you didn't want to worry about blooming, etc.

For LCD's I don't agree with 80cdm^2 but I also don't agree with 120 or 160, unless maybe you're in an office with lots of very bright overhead lighting. 100cdm^2 works far better for me and would be a better recommendation for most home environments IMHO, assuming your display can be calibrated for that level of brightness.

I thought Mark's main point about adjusting brightness was this:

"The problem is that if you take a standard LCD computer display and begin to lower the brightness below its optimum design point, you also negatively affect the display’s performance. All of a sudden it can no longer display certain colors, and it loses even more uniformity across the screen. It gets all “blotchy” and the gamut and dynamic range get reduced."

His hypotheses is that "standard" displays don't work all that well at a brightness setting that is suitable for photography.

Dave

My theory was that the brightness helped the contrast range and that a good profiling would account for the brightest stuff to remain bright, but adjust the response curve so that the other tones fell in line with the rest of the screen's capabilities.
Though my perspective comes from the fact that most of my work ends up for use online, where other people are looking at it on those bright monitors.
The article is from the perspective of a print. There will always be a bit of a juggle trying to get an additive color (light emitting) device to accurately portray the outcome of the same image in a subtractive color (light reflecting) media. They are fundamentally opposite ways of generating color.

of course, but the same applies to the black point. The numerators smaller than 1 of the black point have a much higher impact on contrast than the brightness level.

120 - 0.3 = 400:1
120 - 0.2 = 600:1
120 - 0.15 = 800:1
180 - 0.3 = 600:1
180 - 0.2 = 900:1
160 - 0.2 = 800:1
100 - 0.2 = 500:1
100 - 0.25 = 400:1

The point is, that in IPS type panel the black point is relatively high, so the contrast ratio at lower luminance levels can be to small. Not a case in Eizo, where you get over 400:1 at 80cd/m^2, so at higher luminance you even have to cut the black point, otherwise contrast gets too high.

The recommended brightness is that which matches a print based on how you view that print. Mark's correct about the "my prints are too bright" issue being to bright a display, too bright if you take the viewing conditions into account. But what are those conditions and can you control them? On my GTI booth, I have a digital dimmer. Its currently set to 50% with my NEC SpectraView at 150cd/m2. I can raise or lower each within reason. I can move my Solux task lamp closer to or farther away from this booth (with the Fluorescent off of course, I often use one or the other). So anyone who suggests there's one right setting needs to define both the display and the booth conditions. Otherwise its a lot like one had clapping.

As for contrast ratio, the values above are correct since all you need to do is some simple division. The question becomes, do you have control over both the black and white target values of the display? No problem with better CRTs. And a few LCD's with better panels and software control allow this. This adds another value into the mix so now not only do you try to get cd/m2 for the backlight set to match the booth, you've got the black level too. When the planets all align, you might get all three values to be something someone says is "correct" but its usually trial and error (if at 120 - 0.3 = 400:1, which is STILL TOO HIGH), the viewing booth might be such that the soft proof looks too high or low.

In the case of my NEC, I simply tell the software what contrast ratio to hit as well as the luminance of white and off it goes. It doesn't always hit the value exactly since there's a mathematical compromise plus I have to view the prints in the booth, adjust that and/or the display target values again.

Driving displays lower does let them last longer.

Oh and by the way, a bigger gamut display isn't always better. In some cases, depending on the work you do, its a definitive negative. The article kind of makes it sound that an Adobe RGB like display is preferable. Not in many cases where you are working with very subtle color images that fall within sRGB gamut.

exactly.

I agree - all the values are pretty much useless unless you see roughly the same on screen and in the viewing box.
I always adjust my white point by hand... so I end up with a certain x/y value that matches paper white in the viewing box visually. The same applies to the brightness level.
As to the contrast I also agree that 400:1 is somewhat high for the comparision screen-> print. That's again such a questinable recommondation. I am working at something around 350:1. Still 400:1 is not too far away and viewing in softproof mode with simulation of "black ink" (but without paper simulation) the resulting contrast pretty much matches the print IMO.
But, yes, it depends very much on perception and this is why all values are useless unless they respond to the conditions visually.

As long as we are reviewing the reasons for the "my prints are too dark" complaints, I'll mention the output curves in the print profile. In my limited experience, it seems most are designed to maintain highlight separation at the expense of pushing the shadows to black. This not only kills the separation in the shadows, it can cause some images to actually turn out too dark - no matter the lighting. Not that this is a flaw in the color management. The print can only handle so much tonal separation: if you put more in the highlights, the shadows suffer. It's is just the nature of the beast. Those who soft proof correctly, identify the problem before printing an can compensate. But they are not the source the of common complaint.

This brings us to the other most common complaint: maybe someday Lightroom will have soft-proofing.
When they do, I hope they have presets for: 1) Maintain highlight separation (this is tricky because they would have to assume the contrast of the monitor vs. the lighting of the print as you have already mentioned, but assumptions already seem to me made by most profiles). 2) Maintain shadow separation. 3) Uniformly decrease contrast (maybe impose a linear-in-L* curve from the the media white point to the print's blackpoint, accounting for BPC). And being lightroom, I assume they'll offer some user defined options.

Something that I've started to notice with LCD displays on both monitors and laptops is that now some manufacturers (ie Dell) are quoting the percentage of the gamut covered by their displays.

For example, the cheaper laptops and monitors typically only cover 70% of the "standard" gamut (which standard is mentioned in their product details.) I imagine that as you spend more $ the gamut coverage does not shrink...

This may provide you with a rationale for buying a more expensive model for picture viewing/editing and a less expensive one as the "console."

I purchased an Eizo CE 240 W several months ago. It took me a little while to adjust to the darker screen, but, my print brightness is always spot on. Prior to the Eizo, I made allowances for dark prints and still occasionally would get the dark print.

My experience went like this: I calibrated the Eizo using X-Rite's Eye-one hardware and software. The results were not good when printing. Called Eizo's customer service and received information, similar to Mark's article, about screen brightness. Apparently, X-Rite tends towards the bright side. I download their calibration software and used it with my Eye-One hardware. What a difference. My prints always match my screen and I never get a dark print.

No doubt Eizo's customer service and extended warranty add to they higher cost basis, but, to me, it is money well spent.

In the artcle we can read "First of all, look at the gamut versus Adobe RGB:
The display gamut is larger than Adobe RGB and larger than the Epson 9900 with my favorite papers. Hurrah!
At Eizo website,
http://www.eizo.com/products/graphics/cg301w/spec.asp
CG 301W specifications are:
Gamut Coverage
sRGB 99%
Adobe RGB 97%
Who's right?

I don't know what paper you use, or the profile used in the article but I'd be very, very hard pressed to believe its anything close to the gamut of a 9900! That just sounds wrong by a long shot.

Moose Peterson's blog was trumpeting a new X-Rite calibrating product--I know, Moose is always pushing new stuff. What's interesting is his coming to the conclusion that reduced brightness produced better prints.

Here's his comments:

3
Sep
09
ColorMunki
Posted by Moose under Great Stuff
No Comments

colormunki

Long story short, motherboard fired taking out my digital library computer. Dell got me a loaded T5500 is record time (6 business days) so I’ve been rebuilding the system. About a month ago X-Rite sent me a ColorMunki to test (who comes up with these names?) but it wasn’t a priority so here it sat until two days ago. I’ve been profiling with the EyeOne for years now and it always did a great job. It always set my 21UXs brightness near the max though which always bugged me, but the color was for the most part spot on. I had tried the ColorMunki on the notebooks but that doesn’t really count to me since notebook LCDs have so few controls. But it does a really nice job there so I went for it and loaded it on the new computer.

The first thing that shocked me was the ColorMunki had me turn down the brightness on the 21UX. I mean, from 98 to 47! It had me fine tune the contrast but that brightness, in my mind I figured it wasn’t working. It went through its light show and said all done. Since I run dual 21UX on my desktop I clicked next and it instantly jumped to the 2nd 21UX. Again, it had me turn down the brightness. When all finished I looked at the monitors with various images and I swear they looked better than before with the old computer. How could that be with the brightness turned down so far? The human brain ain’t too good at remembering such things so I figured I was just not seeing the drastic change I thought should be there. OK, I’ll process a new file from NEF to 24×30 print using my usual workflow. If the Munki is right, the print will be spot on. If my logic is right, the print will be dark. My jaw hit the floor as the print coming out of the Epson 7900 (great printer!) was spot on! Damn, it was gorgeous!

No clue how the ColorMunki works, I just know it really, really does! One thing it does is do an ambient light reading through a sensor at its top which at first I thought was really dorky. Wrong! It makes you jump through a number of hoops as you spin the dial (be careful NOT to click the Calibration lever in the middle of the dial, confuses things) but the overall time to calibrate from start to finish is faster and in my opinion, much better! The ColorMunki is by far the best profiler I’ve ever used!

Now, if I can just get PS to play with the computer resources nicely!

So how can the luminance of a display affect a print? Answer, it can't. It can affect the soft proofing (correlation between the screen and the print), but obviously it can't affect the print itself.

47cd/m2? I'd be hard pressed to even work at the previous values (98cd/m2 with a newer LCD). What's he talking about?


Neither do the other LCD's (there's nothing to adjust other than the backlight anyway).


It made him? You tell the software your calibration target values and it then asks you to adjust accordingly. So he must have done something here to "tell" the software what he wanted.

Cut him a break. Brightness is perceived not measured. Reducing luminance gave him the perception that the LCD was less bright. The results are the same, his prints were spot on. Nothing about the monitor affects the print; but, it can affect how we adjust the image file, which has an effect on the print. Isn't that why one should make image adjustments on a properly calibrated monitor?

of course. But don't forget to set and control the ambient light, i.e. the lighting conditions under which you eye up prints and edit the files on screen. If at 47cd/qm the screen white level matches the prints white level under appropriate viewing conditions... then either the printer or the colormunki is completely off.

He didn't say anything about cd/m2, at least not in the quote above. I would assume that the 98/47 numbers are the numeric brightness setting of his LCD, probably on a scale that goes to 100.

I have my Eizo CG241W calibrated to 95 cd/m2, and it doesn't look too dim to me. I get a good match for prints, and the brightness level is comfortable for my ambient light. It probably helps that this display has nice deep blacks, so I still get a pleasing contrast range. I guess on LCD's with poor blacks things might look a bit flat at that luminance level.

If I had to work on a display calibrated to 150 or even 120 cd/m2, it wouldn't just make getting a match with prints more difficult - it would make me miserable due to the eye strain.

No, Luminance, which is what we set is not brightness! Luminosity is a measure of the total radiant energy from a body. It has nothing to do with what a human observer perceives but rather describes the total radiant energy, such as watts/second of a source (the surface of a radiating object like a display). So what values is he describing other than the luminance values of the target he's supposedly calibrating to with said software?

Lightness is a perceptually scaled component of color, the axis seen in Lab (Lstar) from light to dark. It IS the L in HSL.

That's possible but it would be far more useful to supply actual target calibration aim points using cd/m2 since the scale of the buttons on a display are meaningless.


All depends on the viewing booth. On my GTI booth, dimmed to 50%, I'm getting screen to print matching with a target calibration of 150cd/m2. I could lower the booth (and the display) but with at least this unit, going below about 120cd/m2 introduces the dimming in the panel and not via the actual Fluorescent backlight. And no eyestrain here.

I believe you are taking this too far for the average or above average photographer, without a PHD in the related field. I understand luminance as a measure of the visual perceived brightness of an object. Here is abstract from a paper written by 3 medical doctors/researchers:

"Brightness—the perception of an object's luminance—arises from complex and poorly understood interactions at several levels of processing1. It is well known that the brightness of an object depends on its spatial context2, which can include perceptual organization3, scene interpretation4, three-dimensional interpretation5, shadows6, and other high-level percepts. Here we present a new class of illusion in which temporal relations with spatially neighbouring objects can modulate a target object's brightness. When compared with a nearby patch of constant luminance, a brief flash appears brighter with increasing onset asynchrony. Simultaneous contrast, retinal effects, masking, apparent motion and attentional effects cannot account for this illusory enhancement of brightness. This temporal context effect indicates that two parallel streams—one adapting and one non-adapting—encode brightness in the visual cortex."

I guess this clears it up. Life is too short, I'll continue using the definition I was given years ago.

Brightness SEE:
http://www.crompton.com/wa3dsp/light/lumin.html

A photometer and a pilot's eyes are receiving light from the same point on a display' s screen ( SEE cover photo). Measuring the luminance of the light from that point is straightforward and highly repeatable We can go a step further and take a second measurement at a different point on the screen. We can then calculate the contrast between the two points. The pilot's perception of brightness, however, is complicated by human visual phenomena such as time-dependent light and dark adaptation, simultaneous contrast, lateral inhibition (Mach effect), dazzle (contrast overload), and color. The pilot's perception of display contrast is intimately related to his perception of brightness .

The concept that is now known as "luminance " was for many years designated by the term "brightness. " This led to much confusion between the objective concept of "brightness" as intensity per unit of projected area, and' the subjective concept of "brightness" which referred to a sensation in the consciousness of a human observer. The newer term "luminance" was adopted to avoid this confusion. - from Optics by Francis Weston Sears (Addison-Wesley, 1949)

Is there enough of a difference between luminance and brightness to justify the distinction? Has there ever been a case where a display had an incorrect specification, didn't perform properly, or cost too much because somebody said "brightness" when he or she should have said "luminance"? Many professionals in the display community say that they say "brightness" because many people don't know what "luminance" is. But to believe that the words brightness and luminance are essentially interchangeable ignores the clear distinction in the definitions of these two words, and the differing realities behind the words. If the luminance of a viewed light source is increased 10 times, viewers do not judge that the brightness has increased 10 times. The relationship is, in fact, logarithmic: the sensitivity of the eye decreases rapidly as the luminance of the source increases. It is this characteristic that allows the human eye to operate over such an extremely wide range of light levels ( SEE Fig. 4).

Also see:http://en.wikipedia.org/wiki/White%27s_illusion
White's illusion is an optical illusion illustrating the fact that the same target luminance can elicit different perceptions of brightness in different contexts.Brightness (also called effulgence) is an attribute of visual perception in which a source appears to emit a given amount of light. In other words, brightness is the perception elicited by the luminance of a visual target. This is a subjective attribute/property of an object being observed.

As the Chinese proverb says: The first step towards genius is calling things by their proper name.

How can this be so? His post is so confusing as he first writes:


Then after dialing down the Luminance he says:


Can this be explained?

I thought we had agreement. Life is easier knowing that there are many factors that effect one's perception of brightness, but, not needing to dissect the factors every time you talk about a monitor's brightness. A reality check is needed before criticizing a photographer for not understanding the science or finding it necessary to explain the science behind the subject. Surprisingly, most photographers take pictures and leave the science to others. I don't think science motivates people to read photographer's blogs. They just want to learn how to take better pictures.

We can agree upon one thing, this dead horse has been beat enough.

We agree that Brightness is a perceptual human visual phenomena, I'm not sure we agree that Luminance is a different term and condition. The two are not the same.



Who criticized who for what? I'm not at all sure what Moose is saying, its very unclear, down to the values he's talking about (one could reasonably assume 98 is 98cd/m2 but again, the copy of the blog is so unclear, I'm not sure what his point is). If someone can clarify this, great. If there is criticism, its only due to a lack of proper communication. Considering how many people find the task of properly calibrating their LCD displays (my prints are too dark), what values to hit and why, I think its a disservice to muck up the discussion with blog posts like this.

My understanding is luminance is one factor that can affect one's perception of brightness. Guess I need to go back and read your book, it does sits near my computer. BTW, I read Moose's comment with an assumption of his intent, not as a learning opportunity.

Thanks for taking the time to discuss this topic.