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henk

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Confused about LCD luminosity
« on: April 10, 2009, 03:57:25 pm »

Confused about LCD luminosity

In the old days of CRT’s a luminosity of 90 was correct. For LCD’s first Gratag Mcbeth advised 140 but corrected that after 12 months. Now the norm seems to be 120. I bought a new LCD monitor from EIZO, CE 240W. Eizo delivers software that works with the Xrite iOne which makes it easy to calibrate. As standard setup for photographers the profile is 6500, 2.2 and for luminosity 80. Is this correct? I have not yet been able to test but since my prints with luminosity 120 were spot on, with home brewed profiles, I expect them to be to light. Why the differences in advice? ?

Henk

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Wayne Fox

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Confused about LCD luminosity
« Reply #1 on: April 10, 2009, 06:53:11 pm »

Quote from: henk
Confused about LCD luminosity

In the old days of CRT’s a luminosity of 90 was correct. For LCD’s first Gratag Mcbeth advised 140 but corrected that after 12 months. Now the norm seems to be 120. I bought a new LCD monitor from EIZO, CE 240W. Eizo delivers software that works with the Xrite iOne which makes it easy to calibrate. As standard setup for photographers the profile is 6500, 2.2 and for luminosity 80. Is this correct? I have not yet been able to test but since my prints with luminosity 120 were spot on, with home brewed profiles, I expect them to be to light. Why the differences in advice? ?

Henk

I don't believe there is a "correct", only recommended.   Personally I don't remember ever seeing 80 recommended ... it's more like 110-130 with LCD displays.

The "correct" setting is the one that delivers the same visual brightness as your viewing conditions when evaluating a print.  If you can adjust the brightness of the viewing conditions, then you can set to a standard, and make the adjustment with the brightness of the viewing station/area.  If your viewing area does not have variable brightness (such as my GTI desktop viewer), then you adjust the monitor luminosity(brightness) to achieve a match  ... I do this by comparing by the white of an unprinted piece of paper against a blank white document in Photoshop.  In my case, the Apple 30" cinema display matches at 115.

You shouldn't expect prints to be light or dark ... the very purpose of dialing in this setting is achieving a density match with printed output.  Use whatever luminosity  that achieves this as the end result.
« Last Edit: April 10, 2009, 06:54:24 pm by Wayne Fox »
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jjlphoto

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Confused about LCD luminosity
« Reply #2 on: April 11, 2009, 09:55:02 am »

When LCD's came out, they were simply not as good in the shadows as a good CRT, hence, you needed to run them fairly high, 130~140cd/m2 or so to get a mere glimpse of shadow detail. Now that we are perhaps seven years or so past their debut, they are much much better now. 110cd/m2 will render great shadow detail on a quality LCD calibrated/profiled properly.

Another more anecdotal issue, CRT's generally were designed to run at 80~85cd/m2. Hence, you needed to view them in a fairly dim environment. If you did not have access to a dim environment, and attempted to crank them up to nuclear frying levels of 90, 100, 110, etc, you were guaranteed to  prematurely burn out the CRT's phosphors. Not good. When the LCD's came out, and it was found that they could run brighter natively, so there was this stampede 'out of the cave' and folks began to enjoy working in more friendly environments. Soon the mantra became 'the brighter the better', and attempts to match the monitor to the whites of a print in a viewing booth were simply tossed out the window. Not good. The new iMac's run at over 200cd/m2 out of the box and it takes some effort to get them down to proper ICC standards.
« Last Edit: April 11, 2009, 09:56:09 am by jjlphoto »
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ddk

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Confused about LCD luminosity
« Reply #3 on: April 11, 2009, 12:24:04 pm »

Quote from: henk
Confused about LCD luminosity

In the old days of CRT’s a luminosity of 90 was correct. For LCD’s first Gratag Mcbeth advised 140 but corrected that after 12 months. Now the norm seems to be 120. I bought a new LCD monitor from EIZO, CE 240W. Eizo delivers software that works with the Xrite iOne which makes it easy to calibrate. As standard setup for photographers the profile is 6500, 2.2 and for luminosity 80. Is this correct? I have not yet been able to test but since my prints with luminosity 120 were spot on, with home brewed profiles, I expect them to be to light. Why the differences in advice? ?

Henk

I have the same model Eizo and luminosity of 80 on this monitor and 83 on Apple Cinema Display has always worked for me and matches my print profiles. My prints turn out too dark if I base my pp on higher luminosity settings.
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tho_mas

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Confused about LCD luminosity
« Reply #4 on: April 11, 2009, 04:47:38 pm »

Quote from: henk
Confused about LCD luminosity
If there is no direct comparision you are adapting to the monitors luminosity as well as to the white point. Our eyes are always adapting to the "brightest" white on a display (even if it's just the small menu in the palettes of Photoshop). However the contrast should not be too high. 400:1 is a good starting point. With higher contrast (and 400:1 is higher than any print) you are no longer able to differentiate dark tonal values very good (or better: it's tiring).
Whether you set lum: 120cd/m2 & black 0.3cd/m2, 140cd/m2 & 0.35cd/m2 or 160cd/m2 & 0.4cd/m2... that's all fine.
Compared to a viewing booth which typically has a luminositiy of around 500lux 160cd/m2 should match (which is basically the recommendation of the "Fogra" -> http://forschung.fogra.org/index.php?menui...mp;reporeid=122 [German]).
In any case the monitor should be the brightest light source.

I find it really useful is to set different backgrounds (white, mid grey, dark grey) for the final print file to compare.
A bold white frame around the image should tell something about the basic luminosity of the image if you are adapting to it 2 minutes or so. Same with the dark grey (e.g. L*20). Just to eye up the softproof! While editing I set the backround in Photoshop to a bright grey of L*78 (which is the "light" grey in Capture One V4).
« Last Edit: April 11, 2009, 04:51:57 pm by tho_mas »
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henk

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Confused about LCD luminosity
« Reply #5 on: April 14, 2009, 02:27:59 pm »



I find it really useful is to set different backgrounds (white, mid grey, dark grey) for the final print file to compare.
A bold white frame around the image should tell something about the basic luminosity of the image if you are adapting to it 2 minutes or so. Same with the dark grey (e.g. L*20). Just to eye up the softproof! While editing I set the backround in Photoshop to a bright grey of L*78 (which is the "light" grey in Capture One V4).
[/quote]

Thanks folks, I am on the move now in Spain and not able to test print. But what I learned from you is that the luminosity setting is more based on what the print tells me than a “ luminosity standard setting” . The hint from tho_mas to set different viewing conditions on the sceen I will try as well.
Henk

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Pat Herold

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Confused about LCD luminosity
« Reply #6 on: April 15, 2009, 07:56:35 pm »

If you are specifically trying to match your display to a print next to it, the luminance of the display should be closely tied to how bright your viewing condition is.   We frequently run people through what we call "the white paper" test to set their luminance.
http://www.colorwiki.com/wiki/Printer_to_Match_my_Screen

I think the recommended value for luminance changes, depending on the market into which a display is intended to go.
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Wayne Fox

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Confused about LCD luminosity
« Reply #7 on: April 15, 2009, 08:10:44 pm »

Quote from: ddk
I have the same model Eizo and luminosity of 80 on this monitor and 83 on Apple Cinema Display has always worked for me and matches my print profiles. My prints turn out too dark if I base my pp on higher luminosity settings.


That's fine,  but your number is based on the brightness of your viewing condition.  It has no relationship to someone else's value.  My ACD requires a luminance of 115 for a good match to my viewing conditions.

The correct luminance is the one that matches the brightness of the individual viewing conditions ... and it will vary for every single person out there.

In fact, if your setting is that low you may want to consider brightening up the viewing station.  This sounds VERY low and dark.  I'm not even sure my ACD can go that dark and maintain any accuracy.

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