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IR measurement trick...ery?
OK! I admit it! I am confused!
It seems that many people are using an 87 series IR
filter and an EI of 3000 - 12800 to get usable
exposure data from visual light meters for infrared
film.
How does the IR filtered Light meter actually work in
practice? Are we certain that it is in fact measuring
IR? Can readings be made in total darkness? (With of
course an IR source present)!
I realize that there are several filters used and they
each have their own ... whatever you call it, and they
may or may not pass a small amount of actinic,
non-infrared light.
I also know that I have been told that ordinary light
meters CAN NOT measure IR because they do not sense
it.
Do ordinary light meters have the ability, even
weakly, to sense IR? Could this commonly repeated here
say have been faulty info?
If light meters can read IR, but are not very
sensitive, then I can understand how this method
works. Otherwise....perhaps it's back to the leaky
filter theory....
Drip, Drip, Drip...
Ray
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