[argyllcms] Re: Tests with DTP92 on video-projector

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

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