I have used my 124G with an 89B (695 nm cutoff) and didn't really worry about it; unlike the earlier IR films, the light spectrum for today's IR films barely extends outside the visible spectrum and as such I don't think compensation is that important. Now I admit that is an opinion, not carefully researched fact.
That said, I think on many lenses the IR adjustment amounts to using approximately the next depth of field mark toward closer focus as the indicator mark.
Last edited by DWThomas; 01-23-2013 at 11:01 AM. Click to view previous post history.