Great ! This helps a lot. It seems I don't need the special i1 Beamer upgrade at all. I think I can manage to install the device in such a position that it correctly captures the colours on screen in other ways. And for the calibration, there is a cap that comes with it with a white spot in the center, so that should work ok. Thank you for the extra info ! Geert On Wednesday 2 April 2008, Graeme Gill wrote: > Geert Janssens wrote: > > Questions: > > - I suppose this complete darkness can also be recreated in other ways by > > carefully covering the lens opening of the i1 Photo ? > > - Is this spectro calibration standard procedure before profiling ? I > > mean, does ArgyllCms do this also and is it required ? > > Yes, it's standard to calibrate the device before each use. In emission > measuring mode, it's usual to block the sensor using the white > reference, and calibrate the black level. > > What I've done is simply calibrate it this way, and then put the > device in position. If you need to stop and start the > software, use the -N flag to avoid re-calibration while it's > in position. [ The previous calibration for that mode > is stored in a file, and will be read in each time the software starts. ] > > > - How can I point my spectro to the screen center using Argyll ? Does it > > also have some software trick for this ? Or are there some independent > > tools I could use for that ? Note that I am limited to linux, so using > > X-Rite's software isn't really an option. > > It's really just a matter of making sure that the instruments field of view > is filled by the screen, and that it isn't seeing it's own shadow. If you > are operating with more than one display (so you can operate the > software without needing the display being measured), you can fill the > display being measured completely, using the -p parameters (e.g. -p 0,0,10 > will usually do it). > > > Also, imagine I manage to get the beamer/screen combo profiled. I suppose > > such a setup is even more susceptible to influences by ambient light ? I > > can't fully darken the room whet the beamer, so outside weather > > conditions will definitely play. In the end, I may have to go for > > Frédéric's procedure, and profile the beamer only. > > Yes it will be influences by ambient light, and it will also be influenced > by stray light from the screen itself being reflected back from the > surrounding environment. This might be a reason for not filling the whole > screen with the test colors. But if the screen normally has a level of > ambient lights, then there is nothing wrong with capturing the way it > appears, and going from there. > > Graeme Gill. -- Kobalt W.I.T. Web & Information Technology Brusselsesteenweg 152 1850 Grimbergen Tel : +32 479 339 655 Email: info@xxxxxxxxxxxx