Roll 198: Astrum IR200. I am trying to find a substitute for Rollei IR films, and a hand roller over on photrio had some of this film stock for sale. I received the rolls earlier this week, tried to do my usual film speed characterization test, but I mistakenly loaded this roll into the A12 back rather than the A16 back, so there is a gap in the data.
This film is advertised as "not Aviphot 200, instead it is actually ISO200", so I assumed Rodinal would give me a 1 stop penalty and I would land at ISO100. If the film had indeed been ISO100 then the -4 frame should have given me a density of 0.1, but instead I need an extra 1.5 stops of light to get that density so the film is 1.5 stops slower than metered -> ISO36.
ISO36 seems awfully slow for an "ISO200" film. Perhaps my light panel is to blame as it probably has zero light in IR. But I used this light panel for Rollei Retro 400S which gave me ISO100, so perhaps my developer is toast? I'll develop a known-good roll next and verify. Perhaps Rodinal is just bad for this film.
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