I thought that Konica was just as sensitive to the visible spectrum as the Maco 820 and Ilford SFX films.

I have found that the Maco 820 film works best with either the 88A or 87 filters; anything less and you won't see the IR effect. Ilford SFX gives a good IR effect with an 89B/R72 filter.

I've never heard of an anti-curl layer on the Maco films. I know there's an anti-halation layer on the 820c Precision film. How warm was your water?


Quote Originally Posted by AllanD
You will have a problem problem with any IR film that retains significant visible light sensitivity when used with a red filter. This includes Maco 820 and Ilford SFX, but not (I think) the Konica film. There may be some IR effect, but there will be significant density due to the visible light (i.e. they wont have the effect you are looking for )

I tried one roll (!) of Maco 820 (in 120 format) using a red filter and the results were disappointing, with, to me, no IR effect whatsoever. I guess that a proper IR filter is required with this film. The film is fine grained. The EI is a notional 100, although Maco don't tell you this ! I never worked out a personal EI; I just derated according to the filter factor.

BTW, I made the mistake of washing the Maco film in water that was slightly too warm, resulting in the anti-curl coating dissolving. This made a right old mess. I have never had this problem with any other film.

I have used a fair amount of Ilford SFX in 120 format with their SFX filter. This produces a quite surprising amount of "IR effect" on a sunny day and is what you might call "medium grained", with no halation. The fact that you can't see throughout the SFX filter is a serious impediment to wedding photography! But you need the filter to get the IR effect. The notional EI of SFX is 200, one stop faster than Maco 820, giving you more margin for hand held. It half the price as well, so you can feel less bad when it all goes wrong.

In theory, flash photography is a rich source of IR. What the proportion of the output is in the IR region (and hence, what "look" you get) depends on the flash unit. I guess the thing to do is put an true IR filter over the head a powerful flashgun (strobe) and start experimenting.