[argyllcms] Re: i1d3 Teardown

  • From: Graeme Gill <graeme@xxxxxxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Mon, 03 Feb 2014 22:04:07 +1100

Richard Hughes wrote:
> I'm kinda
> confused about that giant lens tho, surely the beam needs to be
> collimated from a narrow angle, although I don't know how the diffuser
> would affect things.

The main lens focuses collimated light onto the diffuser, the second lens 
focuses
an image of the diffuser onto sensors. The diffuser ensures that the three
sensors see a uniform sample color, as well as eliminating any polarization.

Nikolay Pokhilchenko wrote:>  3 Feb. 2014, 8:49 UTC от Richard Hughes wrote:
> The glass filters seems to be interesting: they are semi-transparent mirrors 
> with the
> coatings that reflects unwanted wavelength and passes the needed. Surely the 
> filter
> coatings are multi-layer to achieve desired spectral transparency shape.

They're thin film dichroic type filters of course. See this article for an
idea of the type of thing X-Rite and others might have done to design such 
filters:

<http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.133.5284&rep=rep1&type=pdf>

Graeme Gill.

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