On Mercredi 05 Avril 2006 16:33, Graeme Gill wrote: > Hmm. I was thinking about this sort of thing. You might get away with > pointing it at the screen, but it may or may not work satisfactorily. That's what I did ! I thought that pointing to the projector will overload the DTP92, so I didn't even try... > More light is better, assuming you don't overload the '92. Also, since > the RGB sensors in the instrument are distributed around the inside of > it, you probably want to keep it "flat", so as not to favour one sensor > over another. It is not easy to keep it really flat, as you must avoid its own shadow... What are the maximum XYZ values a colorimeter can return ? Is the maximum really reached with pure white ? > A better optical arrangement might be to make a telephoto adapter. > A tube (painted black on the inside), with a lens at the right > point, and a thin diffuser at the focus. You want to project > a focussed image of the screen on the diffuser, and then put the > DTP92 on the diffuser. The diffuser would have to be neutral > in terms of it's effect on color. (this is just theory, I > haven't tried anything like this myself. If I could locate a source > of suitable lenses in Australia, I might give it a go.) Good idea. I will try to do that. The 'neutral' diffuser could be the hard point... -- Frédéric http://www.gbiloba.org