Hi Mark, with regards to Ilford SFX, I have used this film to good results. It doesn't have the sort of ethereal appearance of Kodak HIE, but that's because HIE lacks antihalation layer (which makes most of its IR pictures too pictorialist and ugly, unless used carefully). Of course SFX's sensitivity to IR is much lower than true IR films. This one is just traffic surveillance film, meaning it peaks around 700-720nm. But this is, with care, quite sufficient to get good "IR" effect, meaning white chlorophyl leaves and grass. The care is this: do not use plain red 25A filter, get at least deep red 29A or better an almost-IR filter which blocks most of light below 690nm. I used just such filter (it's _almost_ opaque), and got exposures at around f/5.6 1/30 on sunny days. You can see some examples of my work with it at www.volny.cz/ffranta , section Scapes, section IR (the pictures were, some more, some less, digitally manipulated to enhance the IR effect, I admit). So definitely, with using _proper_ filter with it, IR effects are possible. The benefits are cost, easier loading, good antihalation layer (big plus imho), and good sensitivity even with the 690nm cutoff filter (especially over the Konica which is impossible to use handheld with such filters).
Good luck with it. Search the W.J.Markerin (?) site, or some other, there is floating on the web an excellent comparison of all IR films, including SFX, containing actual pictures of the same scene (landscape) shot on all the films! I forgot the address though :( Good light, Frantisek Vlcek
