Anyway, based on your analysis, I must have removed filter 2, because I got a large red boost on its removal (and the histogram was really obvious), this would not have happened if filter 1 was removed (assuming as you say, it doesnt block IR). Christians picture and position/description of filter 2 is the same as the filter I took out, I really now dont doubt thats the one I took out. But still leaves us with two 40Ds with different IR responses
