The Big Exposure Table for IR Films - enter your data here!

[cmo]

CMO,

Were the above examples Rollei IR 400?

No. Efke IR 820 Aura.

 

[cmo]

Trying to build such a table is useless. There is too much variance in IR radiation on various days, weather conditions, latitude, time of the year, time of day, weather patterns, atmospheric haze, etc. it is a waste of time.

Hey, it works, at least for me

 

[cmo]

Some development variations were tried including hot paper strength Dektol! This was supposed to cure the reputation IR negatives have for low contrast.

It's actually not the films. Most IR pictures suffering from low contrast that I saw suffered from inadequate lighting in fact. As a rule of thumb, sidelight is great, back light is fine, too, as long as reflections in a bad lens or from an el-cheap IR filter don't kill the image.

XTol 1:1 works fine for me. I have some A2 size prints from 35mm negs here and they look great.

 

[Poisson Du Jour]

Poisson, yes, I think you could use foil as you say, I've been meaning to try it for a long while, though actually I am not such a fan of halation so it hasn't been a priority. Anyway the obvious problem is that you have to take care not to scratch the film with the foil. You could also pre-wash away the AH layer from sheet film. Another thought that I've not had time to try is to make a dupe neg over foil using sheet film with the AH layer washed away. I am guessing that you can add halation to any image that way, as long as the enlarger bulb emits enough IR light. ( And if the IR component is small then a visible blocking filter over the enlarger bulb could probably boost the balance of IR, at the cost of a much longer exposure of course)

I think scratching of the film will be unavoidable as the film itself is quite frail, at least that is the reported experiences with Efke Aura. The foil I have in mind is available on a large roll and is normally used as insulation of some sort in electronic circuits. The adhesive is of non-removable grade which sounds a warningn that once it's in place, what happens when you don't want it anymore?

At the moment I'm looking for the thread here on APUG about using a piece of exposed but undeveloped neg. as a substitute "IR filter". It appeared last year IIRC but cannot be sure, darn.