Hello Nikolay, Monday, February 3, 2014, 10:09:13 AM, you wrote: > 3 Feb. 2014, 8:49 UTC от Richard Hughes wrote: > ...Using glass filters probably contributed to the > cost, but otherwise the board is very simple indeed. 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. > I think the lens is needed for enlarging the instrument aperture to > increase the light flow. The last is improving the sensors signal/noise ratio. I suspect you are right. In photography, the f stop is the focal length of the lens divided by the entrance pupil. The latter is the apparent size of the front of the aperture as seen through the optics, and its size (and position) can be quite different from the physical size and position of the iris diaphragm. I suspect a similar principle is in use here. Certainly it gives accurate, fast results even on dark patches. > 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. That would also seem reasonable. In passing I loved the comments made during the video about this device incorporating a license key and being mainly designed to stop people using their proprietary software because "software is more important than keeping your customers happy". Incidentally the proprietary software for I1D3 fights with the same vendor proprietary software for the ColorMunki Photo :) On my personal desktop machine I uninstalled the XRite drivers and use the Argyll ones; on my more recent work laptop I have never installed the XRite drivers or software; always used Argyll with better and more flexible results. -- Best regards, Chris mailto:chris@xxxxxx