Datacolor User to User Support Group.

Hello,

My interest in calibrating (or profiling) displays is not just to get visually acceptable colors, but I also want to use the colors or gray levels for scientific experiments. Therefore, I am interested in how well the Spyder 4 calibrates a display.

I was hoping that with the advanced analysis tool of the Elite version it would be possible to analyze the calibration. Since this tool is meant to look at the hardware only without calibration, I did the following work-around, which I was hoping anyone can tell me if this works: I have two displays and calibrated the second one. On the first I open the color management tool of Windows 7 (x64) and see that indeed the calibrated icm file is the default one. On the second monitor I start the advanced analysis tool, for example the tone response. Right after it started I select on the first monitor the calibration icm file and default it again. This seems to work, because the colors slightly change on the second monitor. So, I think this way I can use the advanced analysis to measure the calibrated state.

I followed the above procedure for my Fujitsu P23T-6 LED IPS monitor in photo mode before and after calibration. I posted the tone response curves before and after calibration in the photos section of this message board in the album 'display calibration verification'. It is clear that before calibration the curve was not nice, but after calibration it still does not look anything like the 2.2 gamma curve (even with iterative gray balance calibration), although it does look different now. The strange thing is that when doing a CheckCal procedure, the software mentions perfect gamma and near perfect color temperature, which does not seem to match with the advanced analysis results with work around.

So my questions are if anyone knows
- if my workaround is indeed valid?
- if indeed valid, why the gray scale calibration seems so bad, while the CheckCal says it is ok (is there an inherent limitation for the calibrating LUT or is it a Spyder limitation and would maybe other hardware perform better)?
- if my workaround is not valid, does anyone know other ways to verify the calibration?

Any hints in the right direction are appreciated.
Gerard

PS At this moment there are no images visible yet in the Photos section of the group, because they need to be approved by the board moderator, but I am hoping the images will soon appear.