Infrared film means that it is usefully sensitive to infrared radiation. However this depends on the degree to which sensitivity stretches into the IR range, and to the magnitude of sensitivity in that range (absolute and in relation to the visible light sensitivity.)
Originally Posted by madgardener
The weakest infrared filter would be 89B (R72). Here you see a comparison of IR-effects on films with different IR sensitivity and different filters employed including ILford SFX with 89B filter:
Ilford SFX200 R72 filter, EI 12
Rollei IR400 R72 filter, EI 4
Last edited by AgX; 01-31-2013 at 06:15 PM. Click to view previous post history.