darkest black, brightest white

[sgwrx]

1. i downloaded something called quick gamma
2. i followed the directions to adjust brightness, contrast on my sony lcd
3. i started to follow the gamma adjustment procedures, but found that using
this program's sliders, nothing changed!
4. i opened up the control panel applet for my ATI video card
5. i left the quick gamma black/white scale and 3 color scales open and visible
6. i used the ATI software to adjust the 3 individual gammas so according to the
program instructions, each color gamma was nearest to 2.2 on the programs scale
(windows xp pc)

next, i followed a 'test' on LL's main page that said create a new image is PS, fill it with black, switch to full screen mode with the black background and hit cntl + m to open up the curves editor. next i selected the output and up'd it 1 level at a time. i found that i noticed a difference in the image vs. the background at 30. i adjusted the brightness on the monitor up a couple steps at a time and get this down to about 18.

next, i noticed that the white's were getting pretty blown out. so i repeated this test with a white image and found i had to come down in the curves output to about 230 before i saw a change in white level. i played again with the brightness and contrast settings to get this to about 245.

so to me, i'm loosing a certain number of blackness levels on the bottom end, and i'm loosing a certain number of whiteness levels at the top.  but what's most important to me now is that brightness seems to be more even across my screen and colors seem to be a little nicer than before.

i'm most interested in blacks and whites at this stage in my learning. is there some way i could take one of my aRGB pictures and post it on this thread and have someone with a calibrated monitor to compare what i see in PS with aRGB vs. what you see?  for example i have a picture of a front porch with black shutters. in one of the shutters, i can see various levels of black getting progressivly darker until finally all the remaining slats blend into one solid black image.

would this help me compare what i see to what a calibrated monitor/system sees?

[Tim Gray]

Better to use an objective file.  Here is a file with 2 gray scales, one at each end of the scale together with the rgb value.  What can you distinguish on the screen and what can you see when you print?

BTW, the method you describe in balancing brightness and contrast is the what I've done since the McBeth eye1 didn't facilitate an automatic solution.

bw gray scales

[sgwrx]

thanks! i can not distinguish between 10 and 15 when viewing in firefox. my ati card has srgb as the default profile.

i can open this in PS and it asks for conversion to working color space aRGB and i see no change. if i open in PS and don't color manage, i still see no change - both versions i cannot see a difference between 10 and 15.  so this is probably a little different that what i stated above as far as using the curves test.

here are two images. one assigned sRGB from the original aRGB capture in my camera and the other converted to sRGB from aRGB in PS.



in assigned sRGB,i cannot see the slats on the bottom of this shutter, they are dark. in converted to sRGB, i can see the slats.  also the red brick appears to have a higher saturation in the converted.

Better to use an objective file.  Here is a file with 2 gray scales, one at each end of the scale together with the rgb value.  What can you distinguish on the screen and what can you see when you print?

BTW, the method you describe in balancing brightness and contrast is the what I've done since the McBeth eye1 didn't facilitate an automatic solution.

bw gray scales
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