Display Luminance: A Question

[Kit-V]

First, thanks to everyone who has helped me walk through the maze of color management. As a neophyte, I am feeling more comfortable with the subject as a result of a lot of reading in the past couple of weeks. However, one of the mileposts of increasing knowledge is the surfacing of new questions.

I recently calibrated/profiled my new NEC display using NEC's "photo editing" target (i.e. white point = D65, gamma = 2.2, display luminance = 140 cd/m2). Subsequently, I processed several images using either Adobe Camera Raw 5.2 or Photoshop Elements 8 using this display profile.

Since I have not profiled my printer yet, I have not run any test prints. After doing so, if I determine that I will get a more accurate print match by lowering the value of the display luminance, what effect will this have on images that were previously processed when the display was calibrated at a higher luminance?

Thank you for your help.

Kit

[Pat Herold]

You don't have to actually profile your printer in order to get an idea of whether your luminance is correct.  Just hold up a piece of your printer paper (or place it under the same lighting conditions you will use to view your prints) and compare the white of your paper with the white of your display.  If the display is too bright at 140, then the prints you will get from a well profiled printer will probably be dark by comparison.  You might interpret that as looking dull, low contrast, lacking saturation.  If you deal with shadow detail a lot, then your prints will probably show less shadow detail than you are expecting from looking at the screen.  

But depending on how much you change the luminance, it might not make a huge difference in your case.  The real problem is with people who didn't calibrate to begin with, or who calibrated to the native (maximum) brightness of their LCD, and then later are switching to a more reasonable luminance.  That can be a difference of 200 cd/m2 or more!

[Kit-V]

Thanks, Patrick. I will follow your suggestion which, I assume, will at least put me in the ballpark for now.

However, my main concern (as noted above) is the effect that lowering the display luminance will have on previously processed images.

Thanks again

Kit

[digitaldog]

However, my main concern (as noted above) is the effect that lowering the display luminance will have on previously processed images.

The only actual effect will be how well it matches the print next to the display under the proper (controlled) viewing conditions. There is no right setting other than the one that produces a visual match. If the print looks good now, in differing illuminants, that’s fine, but only until you account for the viewing conditions next to the display and the display luminance can you get a good match between the two:
http://digitaldog.net/files/Print_to_Screen_Matching.jpg

[Kit-V]

Andrew: Point well-taken. I think that a lot of the questions that I have regarding print matching will resolve themselves once I set up my display-to-printer workflow & print a few test images. It all seems a bit daunting now until I start working through it.

Toward that end, I ordered a copy of "Color Management for Photographers". Ever hear of it?  

Thank you.

Kit