Efke IR820 in diafine?

I shot my first roll of IR820 this weekend, rating it around ISO 6 with an 89B filter and bracketing 2 stops in each direction. I developed in HC-110 1+49 for 10.5 minutes (the massive dev chart says 7 minutes for dilution B, so I added 50%). The negatives are really thin and across the board the 2-stop overexposure is the only usable one.

Has anyone played with using a higher-speed developer like Acufine or Diafine as a way to get some more speed out of the IR films?

Thanks,

-jbl

I've used Diafine with IR820 quite a bit, but not so much for a speed increase as for a compensating effect. It keeps the highlights from blowing out so that, for instance, trees don't become unvariegated masses of white, and I think it generally makes the IR effects look more subtle. To me it makes for photos that are more interesting and less "gimmicky".

I don't rate IR820 as slow as some people do---typically ASA 3-6 with an 89B---but that's consistent across different developers, and I suspect it has to do with my local conditions and the fact that I generally shoot it at morning and evening (when IR levels compared to visible light are relatively high). If there's a true speed gain from Diafine over HC-110 or PC-TEA, it's pretty slight in my experience.

-NT