Hi all!
I recently bought some “Astrum IR B+W Negative” film (I’m just going to call it IR-200), and was told it was very similar to Foto-200 film, but with a 775nm upper limit into IR as opposed to the typical 750nm. Honestly I thought it wouldn’t make much of a difference, but I bought some just to see. I decided to do an experiment with IR-200 and Foto-200, to see if IR-200 is actually more IR-sensitive like they claim. Right out of the tank, I do think I see a difference. Maybe it’s confirmation bias, idk. Looks like the IR-200 (left) might be like, half a stop faster than regular Foto-200?
These films were shot in 2 different film backs on my RB67 within minutes of each other in the sun with no change in lighting conditions. The film was loaded into the same development tank and developed at 68°F for 8.5 minutes, as suggested by massive dev chart and FPP (who sells the IR film under their own brand). EI from bottom to top of both rolls is 25, 50, 100, 200. (Yes I know, that’s a bit high, I meant to start at EI 12 but accidentally set the wrong shutter speed when I started).
Do you guys have any thoughts on this?
I recently bought some “Astrum IR B+W Negative” film (I’m just going to call it IR-200), and was told it was very similar to Foto-200 film, but with a 775nm upper limit into IR as opposed to the typical 750nm. Honestly I thought it wouldn’t make much of a difference, but I bought some just to see. I decided to do an experiment with IR-200 and Foto-200, to see if IR-200 is actually more IR-sensitive like they claim. Right out of the tank, I do think I see a difference. Maybe it’s confirmation bias, idk. Looks like the IR-200 (left) might be like, half a stop faster than regular Foto-200?
These films were shot in 2 different film backs on my RB67 within minutes of each other in the sun with no change in lighting conditions. The film was loaded into the same development tank and developed at 68°F for 8.5 minutes, as suggested by massive dev chart and FPP (who sells the IR film under their own brand). EI from bottom to top of both rolls is 25, 50, 100, 200. (Yes I know, that’s a bit high, I meant to start at EI 12 but accidentally set the wrong shutter speed when I started).
Do you guys have any thoughts on this?