Luminous Landscape Forum

Raw & Post Processing, Printing => Colour Management => Topic started by: Kit-V on March 04, 2010, 10:28:00 pm

Title: Target Luminance Density Setting
Post by: Kit-V on March 04, 2010, 10:28:00 pm
With a goal of good print matching, one of things that I am starting to appreciate as I learn more about color management is the interdependence of the various devices in the workflow. Nevertheless, it would seem that one of the initial tasks is display calibration & profiling. I am using a SpectraView II puck & software on an NEC P221W display. I have selected the SV-II "Photo Editing" target (one of the default choices) which has the following target values:  white point = D65, gamma = 2.2 & intensity = 140 cd/m2.
 
From what I have read, many veterans of color management recommend a lower intensity setting. This gives rise to a few questions:

(1)  Is it reasonable to assume that NEC sets the intensity target of 140 cd/m2 based upon the characteristics of this NEC display?

(2)  Is this a reasonable starting point or should I be using a lower-value target?

(3)  Ultimately, is the selected value of intensity determined by the color matching of the prints themselves?

I realize that I will be doing some tweaking along the workflow to achieve acceptable print matching. But for now I'm looking for a starting point that will be "in the ballpark".

 Thank you for your help.

Kit
Title: Target Luminance Density Setting
Post by: Mark D Segal on March 04, 2010, 10:32:31 pm
What you/they are calling the "intensity" setting is actually the display luminance. You can access a large amount of material in this Discussion Forum in other threads on colour management in which there is detailed discussion of all the questions surrounding the appropriate choice of a luminance value. I recommend that you do some searching and reading in order to educate yourself on this matter.
Title: Target Luminance Density Setting
Post by: JeffKohn on March 05, 2010, 12:49:50 pm
140 cd/m2 is too bright IMHO unless you have really strong ambient light. I use 95 cd/m2 and get a good match with prints.  A lot of consumer-grade displays don't calibrate well if you try to lower the brightness too much, but the "graphics" monitors such as your NEC should be able to go lower than 140 without compromising image quality.

Some people like a brighter display, but then you run the risk of having your prints come out too dark (which is probably one of the biggest problems people have with print-matching).
Title: Target Luminance Density Setting
Post by: Mark D Segal on March 05, 2010, 01:21:02 pm
Jeff, in principle I agree with this, but for me 95 would be a bit low - in my working conditions I've found 110 works better. But that's the whole point here - there is no one magic setting that's good for everyone under all conditions. That's why it's important for the OP to do some reading, get to understand the factors determining the appropriate settings under one's own ambient lighting and printing conditions, and then experiment a bit to land on the correct setting under those conditions.
Title: Target Luminance Density Setting
Post by: Kit-V on March 05, 2010, 01:30:23 pm
Mark & Jeff,

Thank you for your responses. I will continue to research the topic of display luminance. However, it seems that much of the discussion on the topic is either subjective or erroneous, thus, leading to contradictory information & recommendations. Nevertheless, I will persevere to ferret out the facts.

Thank you.

Kit
Title: Target Luminance Density Setting
Post by: Mark D Segal on March 05, 2010, 01:37:32 pm
Quote from: kitvercella
Mark & Jeff,

Thank you for your responses. I will continue to research the topic of display luminance. However, it seems that much of the discussion on the topic is either subjective or erroneous, thus, leading to contradictory information & recommendations. Nevertheless, I will persevere to ferret out the facts.

Thank you.

Kit

Kit - hah - welcome to colour management - was it Bernard Shaw who said that consistency is for the small-minded?    OK, seriously, colour management is good science which provides a tremendous amount of consistency and predictability we never had as recently as ten years ago, but there is a subjective element to all this precisely because the ambient conditions in which we all use our displays differs from person to person, the kind of prints and papers we're using differ, the kind of lighting we use to view the prints differs, and all this eventually depends on human visual perception which varies from person to person; so there is no such thing as one size fits all and advice can therefore appear to be contradictory and erroneous. The best you can do is to be aware of the factors which influence how to set your display luminance, and then experiment to get the settings which work best for you under your display viewing, printing and print viewing conditions.
Title: Target Luminance Density Setting
Post by: dmerger on March 05, 2010, 02:41:49 pm
"A foolish consistency is the hobgoblin of little minds..." —Ralph Waldo Emerson (emphasis added)
Title: Target Luminance Density Setting
Post by: Mark D Segal on March 05, 2010, 02:43:18 pm
Even better Dean!
Title: Target Luminance Density Setting
Post by: Kit-V on March 05, 2010, 03:04:22 pm
Quote from: Mark D Segal
Kit - hah - welcome to colour management - was it Bernard Shaw who said that consistency is for the small-minded?    OK, seriously, colour management is good science which provides a tremendous amount of consistency and predictability we never had as recently as ten years ago, but there is a subjective element to all this precisely because the ambient conditions in which we all use our displays differs from person to person, the kind of prints and papers we're using differ, the kind of lighting we use to view the prints differs, and all this eventually depends on human visual perception which varies from person to person; so there is no such thing as one size fits all and advice can therefore appear to be contradictory and erroneous. The best you can do is to be aware of the factors which influence how to set your display luminance, and then experiment to get the settings which work best for you under your display viewing, printing and print viewing conditions.

I both appreciate & am challenged by the fact that color management is a "moving target". I am certainly not "faint of heart" & am not dissuaded in the least.

Thanks for taking the time to point a rookie in the right direction. But for now....I have a bag to pack. Voy a Mexico manana para una semana. (Translated: "In the winter, margaritas taste better on the beach").    

Kit
Title: Target Luminance Density Setting
Post by: Wayne Fox on March 05, 2010, 03:29:53 pm
Quote from: kitvercella
(3)  Ultimately, is the selected value of intensity determined by the color matching of the prints themselves?
Not color matching but density matching, with the caveat that if the resulting setting is too high  or too low then the viewing station might be too bright or too dim and need adjusted.  Thus for me both 140 and 95 might be getting close to problematic in that the prints might only look good in the viewing station, but not in the real world.  Displays, devices, and personal preferences vary so  ultimately each person needs to land on their own number.  Personally I think around 115 is a good starting point for most.

If you end up with a good density match but seem to have a problem with color matching then you have a different problem, such as poor color in the light source, poor quality display, bad profile (defective device) for either the printer or the paper.  And ultimately you may find you need to make a profile with a slightly different white point to get a good match since this is really the only user controlled variable.  My display profiles to get a good match normally are around 6100k in white point.
Title: Target Luminance Density Setting
Post by: digitaldog on March 05, 2010, 06:35:02 pm
The right value is the one that produces a match to the viewing booth/illuminant next to the display where you view both the display (with the soft proof on) and the print. YMMV. http://digitaldog.net/files/Print_to_Screen_Matching.jpg (http://digitaldog.net/files/Print_to_Screen_Matching.jpg)
Title: Target Luminance Density Setting
Post by: Kit-V on March 05, 2010, 07:03:01 pm
Wayne & Andrew: Thank you.Your comments confirm what I have gleaned from my limited knowledge of color management. Like so many other endeavors, color management strikes me as a blend of science & art - a symbiotic relationship where one entity cannot achieve the desired objective without the other. Good stuff.

Kit