Which one is a better option (to block more visible light and to block less IR light), floppy disk or developed unexposed photographic film?
1They're both terrible. Film may be less terrible depending on... Color or B&W? Negative or reversal? Developed or undeveloped?– xiotaJan 21, 2021 at 2:38
1@xiota Which options are better for the film? I assume developed unexposed color film? am I correct? Thanks– adudeedudaJan 21, 2021 at 3:22
1There's info here that might be helpful: Why isn't using exposed, undeveloped film working as a filter for my DIY infrared camera modification?– xiotaJan 21, 2021 at 4:03
1Yes, but... Why not just buy a cheap 720nm filter? Results will be far superior.– xiotaJan 21, 2021 at 4:20
1The developed color film option may be good enough then. Good luck.– xiotaJan 21, 2021 at 4:40
There are lots of DIY IR-pass filters...
- Stacking colored gels (colored transparency sheets).
- Stacking ND filters.
- Crossing polarizing filters.
- Variable ND filter.
- Floppy disk – particularly poor because of metal content.
- Developed color film. Unexposed if reversal (slide film). Exposed if negative. – Undeveloped and B&W films won't work well because of metal content.
None of them is as good as cheap IR-pass filters. They come in different frequencies that have slightly different effects. 720nm is the most commonly recommended.
If you are shooting digital, modify your camera for "full spectrum" capture. There are inexpensive premodified compact cameras available for sale online.
Why isn't using exposed, undeveloped film working as a filter for my DIY infrared camera modification?