Thanks, Roger.
Another good reason for a cheap filter...in case you buy the wrong one :O).
I think it'll work with the partial box of HIE I have. The other films I guess not.
Or maybe it would with the other films and LONG exposures. Or REALLY LONG exposures.
Another project I had was taking the IR-block filter out of an old video camera, illuminating a changing bag or box with an IR LED and putting the IR-enlightened camera inside the dark enclosure. I was considering how to be sure the LED's had no visible component...my filter could do that.
I wanted to cut 5" rollfilm down to other sizes & have found working with that roll (1000') kind of traumatic in the dark. If I could 'see' it would be less stressful.