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Old 28-09-2016, 01:41 AM
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luka is offline
Join Date: Apr 2007
Location: Perth, Australia
Posts: 1,124
Bojan, I did a bit more reading tonight and the maximum photon wavelength that will interact with the monocrystaline silicon is 1125nm (1.1eV photon energy). Photons with lower energy (higher wavelength) will go through it without any interaction. Now I am not sure what else Canon added to their sensors but this wavelength is probably the maximum wavelength you need to worry about.

Now, the transmission graph for the Rocolax filter stops at about 1090nm, i.e. short of our maximum of 1125nm. While not likely it is possible that the transmission goes up in this small but unknown range. For example, Baader BCF does exactly this, the transmission rises from 0% to 80% between 1100nm and 1140nm (it is about 40% at 1125nm).

Also to consider is that the sensor efficiency at this far IR end is quite low.

Just some food for thought
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