[argyllcms] Re: How can I tell if I'm using my profile? (and other questions)

I found the following test for the presence of color management:

http://www.color.org/version4html.xalter
It's a little bit less subtle. I know that I have color management successfully turned on in firefox 3. But I don't know where it's getting the profile. It says it will use its own default profile if you don't supply one. How would I go about producing a "bad" display profile? I think maybe I wasn't clear about my brightness. When I run dispcal I can select a calibration option where I adjust my monitor's brightness controls to attempt to match the target brightness level. When dispcal is in this mode, it doesn't do anything other than report every second or so another reading of the brightness. But I noticed that even though I did not adjust the display, the reading was still changing. At first the change was fairly rapid and impossible to miss. Each new number that appeared was bigger than the last. My guess is that this is the behavior of the lamp in the LCD, as I know that fluorescent lamps can take a while to stabilize. Trying to calibrate a device that is changing over time is going to be frustrating and confusing. (Maximum brightness is much much brighter than 170 cd/m^2 (painfully bright). I didn't measure it.) As I vaguely recall, when I ran the calibration a while back and requested 170 cd/m^2 (or whatever it was) the final result seemed reasonably close, definitely within 10 cd/m^2 of the requested number. 
Nikolay Pokhilchenko wrote:

For the first question - Here are five pictures on the page:
http://shadrin.rudtp.ru/Personal/Shadrin_news_hot6.htm
they look identical only if the browser have color management. If you need to check your 
display profile, try to load a "bad", inappropriate display profile. If the 
pictures in browser looks worser, then profile works.

The third question - I think, 130 Cd/m^2 brightness was by 6500K white point, 
when dispcal has to decrease maximum level in some channel to fit wite point to 
6500K. The normal native maximum brightness may be 170 Cd/m^2 without any 
drift. It's not a problem.

-----Original Message-----
From: Adrian Mariano <adrian@xxxxxxxxx>
To: argyllcms@xxxxxxxxxxxxx
Date: Wed, 29 Oct 2008 10:19:16 -0400
Subject: [argyllcms] How can I tell if I'm using my profile? (and other 
questions)
I ran dispcal with the -o option so as to produce a profile as output. I loaded the profile using dispwin under linux. Now I go into firefox 3 and color management is turned on. Does firefox find the profile that was loaded using dispwin? Can I observe the effects of this profile? (Am I likely to be able to see the difference between using the profile vs. just calibrating the display and not using the profile?)
As a second set of questions: my goal is simply to get colors to look "right" (good) in pictures I take with my digital camera or if I visit a web page and look at pictures of colorful merchandise, for example. I made the above profile using sRGB, but I noticed the suggestion in the documentation that perhaps a gamma of 2.4 would be a better choice? I think the last time I ran a calibration I specified a temperature of 6500 K, but this time I forgot that option, which apparently means the monitor's native white point is used. Am I better off using the native white point? How long should I expect it to take for my LCD display to stabilize? I sat down and woke it up and started looking at its brightness and it was 130 cd/m^2. I couldn't remember what I'd calibrated it to, but I new it was much higher, something more like 170 cd/m^2, I think. I sat in dispcal and watched the value creep upwards. After, oh, maybe 45 minutes it seemed somewhat stable at 166 cd/m^2, though it might have been drifting a bit still. I assume that trying to run a calibration or a profile while your display is drifting is going to give a poor result.
I am using argyll 1.03 and it appears that argyll disables the screen blanker in X but does not turn it back on when it is done.

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