Gerhard Fuernkranz wrote:
Well, if we'd assume that the filtered light does not contain any energy below 400nm or 420nm, then basically we would have to discard the readings for these wavelengths completely, as they would be the result of a zero by zero division (no light multiplied by the reflectance of the sample (+ noise), divided by no light multiplied by the reflectanceof the reference tile (+ noise)).
This could well be the case, especially as it's an incandescent source and has less energy in the blue to start with. But in theory there is no need to be zero, it just needs to be a lot less than the illumination level used at the emission wavelengths, so in theory the short wavelengths could be measured in spite of the UV filter. Graeme Gill.
