I have that Hoya filter, shooting with a Canon XTI, but my experiments are always super grainy, and do not come out at all like the examples I see online.

Any idea what would be causing that?

If I still have any of my failed attempts from last summer, I'll try to use your tut and see what happens. Maybe if I have the same failure, I can post the link and you can tell me where I'm going wrong.

IR is he first thing I've tried, photographically, that I can't seem to make work. SO frustrated!