I'm planning to try some Efke IR 820 this weekend in sheets and expect to use my new IR092 Dark Red Filter.
Any suggestions on what ISO to start with while using the filter.
I don't mind doing a bit of testing but don't want to use my whole box of film trying to find a starting point.
Also when shooting IR on a 35mm you get the little red mark or IR on the lens to reset your focus to.... what do you do when shooting IR on a ground glass?
This is the data sheet of the IR820C film: Dead Link Removed
RG715 (#88A) and R72 will give around iso 3.
You need some small correction of the distance but I have worked with this film (Maco IR820C, till 2004) in 35mm and 120 roll film only.
I agree with robert. I have used both sheet and roll, the 3 iso is about right, maybe even a stop more exposure. I developed mine in rodinal 1:25 for about 9 minutes. Negatives look ok, have not printed them yet.