Kodak IR film

[fightheheathens]

now that im done with college and have a real job, i can afford film and chems and i've been getting into doing B&W IR film. (Im gonna try some color but its 26 bucks a roll!!!)
Anyway The IR ive done in the past...all 2 rolls... I've shot at 320ISO and developed it for around 8 min (At Terri's suggestion) with really good results.
From what i have learned IR film is very touch and go and The Box tells me to shoot at 50-100 ISO and develope for 7.5 min.
I just got a ND8 Filter and im looking to do some long daytime exposures...(which has nothing to do with this months contest...)
So i was thinking, if its supposed to be shot at 50-100 and i can get great results at ISO 320, Im wondering if how slow can i make this film? 25? 12? 6? If i can pull it down that slow how should i change developement time.
Mind you that many places recomend a developement time of 5.5-10 min...(so its not all that precise)

Thanks for any help

 

[terri]

Glad you're getting good results with the above settings. Just to clarify: my standard ASA is 360 for HIE, with a #25 red filter, and I use TMax developer 1:4 for 6 minutes with extremely gentle agitation.

So, hmmmm....I'm not certain why you want to use HIE at such a low ISO, when the beauty of the stuff is its speed. So first off, you might want to simply try the Maco/Rollei IR film - it comes in 35mm format and you can set a low ISO for it, starting with 25. My husband has shot the stuff on ISO 12 and gets good results, using a near-opaque filter (the Rolleiflex filter equivalent to an 87 or 89) . Me - I don't want to be a slave to the tripod for every frame, so I stick with HIE and the above settings. Just personal preference (read: lazy). :mrgreen:

You will certainly be able to slow the film down with the ND8, but of course, this filter alone won't act like a red filter in blocking blue light and allowing IR to reach the film. So if you're talking about coupling these filters, then you'll see quite a decrease in indicated shutter speeds and an increase in f stops - which is great if you really want to open up. So you'll be able to get those longer exposures....I'm not sure what your development time would be at this rate. You'll have to run a test roll or two to see how it turns out, unless someone else weighs in here with a suggestion.