Got some of these lying around?Well, they can be put to good use - if you have a camera that features "Night Shot" mode. That's the ability to take those greenish black and white photos in near darkness. Unlike ordinary photo film, silicon-based CCDs and CMOS sensors are quite sensitive to the near infrared (NIR) in the 700-1200 nm (0.7-1.2µ) range — so much so, that some of the incoming NIR has to be filtered out in order to reduce IR contamination artifacts. The usual solution is to fit digital camera sensors with special internal IR cut filters. In Night Shot mode the filter is moved away allowing the sensor to use its infrared recording capability. Some consumer-grade digital cameras even let enough NIR through to allow some IR photography without Night Shot mode. The key is to block visible light entering the camera while letting infrared through. And it just so happens that the media in floppy disks are excellent at that job.
So break apart one of those floppy disks...... and remove the disk itself from the shell. Then cut it to size and attach to the front of the camera's lens.Switch to Night Mode or go for as long an exposure as you can and enjoy the glowing results: