Quote Originally Posted by scheimfluger_77 View Post
Newt, I have one of these filters and it is a medium-light orange, factor appears to about 2/3 of a stop with my initial tests. I bought it for use with IR film and get minimal results alone, however combined with a #29 dark red it begins to produce some good ir effect.

As to previous comments about light meters not reading IR, I don't think that's true. A 720nm filter placed over the sensor on my Luna Pro meters give readings within about 3 stops of unfiltered readings, so i expect that like digital sensors there is some IR sensitivity. At least that's been my experience.
Yes, you are right of course. I should have said that they are not calibrated for infrared.

This could probably be done however, if someone were so inclined, so that you could read through an optically opaque IR filter and get a useful reading.