I was always curious how sensitive Light meters are to IR light. I took my Sekonic meters and subjected them to IR light from a night vision scope. Quite to my surprise, both the ambient and the reflective meter was quite sensitive to IR light. Of course, the lower the light levels, the more sensitive it was. At low light levels, say 2 EV, the IR would drive up to 7 EV. At higher light levels, 8 EV, the light meter was influenced between .5 and 1 stop. Of course the night vision scope puts out small amounts of IR light.
Half the suns energy is released as IR energy. The earths atmospher blocks most of the IR light. However, I am curious just how much of the IR is blocked? Is there specific times when the IR levels are higher then others? Certain places? If there was a simple solution, such as using an IR filter over the light meter, however, this is nearly impossible from what I have learned. Possibly another solution would be to use a standard IR filter used for IR film, as if you cut out all visible light, possibly the meter will read an infrared value??
I realize the amounts that may or may not effect the light meter are probably small, but with chrome film every bit helps. Any experience or research data on this subject? TYIA.