I was at a client's today, and they added a second 23" ACD to a G5 workstation, for tool palettes, etc. Probably about 18 months difference in the screens' ages.
Of course they didn't look anything alike, so I had a go at calibrating/profiling them. Used a DTP-94 puck and Monaco Optix XR (Pro I think.) In the expert mode I chose native white point and tried 0.20 for the black luminance, 120 for the white, and 2.2 gamma. After I was done they were closer, but still noticeably different. The older of the two monitors seemed to have a slight magenta cast to it. The newer one was more neutral, but seemed a tiny bit flatter (which will probably be OK, and actually probably give better screen to print matches.)
I guess the question is, how close can I expect two monitors made at different times, with a big difference in operating hours, to look compared to each other? Should I try to recalibrate, and if so should I try to change any of the parameters (particularly the black level, or gamma?) When is close really close enough?
On a related topic, I was re-reading a section of "Real World Color Management" (in chapter nine, about evaluating monitor calibration profiles) and I came across the passage about problems like banding bring caused setting the black point too low, or using a gamma setting too far from the monitor's native setting. Does anyone know the ideal black point and native gamma of a 23" Cinema Display? I ask this because I wonder if making a slight tweak of either black or gamma to the older of the two monitors might bring it closer to the newer one.
Sorry this turned into such a ramble Thanks in advance for your input.
ron