I'm interested in thermal imaging and night vision and applying it to FPV flight. Can anyone recommend a good night vision FPV camera? I've seen the RunCam Night Eagle, and it looks great, if a little expensive. Also, can someone shed light on whether or not it's an IR camera? I'd like to be able to use an IR spotlight or some similar device to light up shadows, but I don't want to have an obnoxious flashlight shining around.
The night eagle (and other 'night' FPV cameras) use visible light, but can work with very low light levels. Moonlight looks like daylight and starlight is flyable. There are plenty of videos that demonstrate what you would see.
Even many ordinary FPV cameras will often work better than normal vision. It's quite common to finish an evening flight and be surprised at how dark it is.
As far as I know, the Night Eagle is still the best but new cameras are released every few months so it's worth checking the latest reviews.
'Night' cameras might pick up some of the nearest IR frequencies, but they're not real IR cameras. You won't see any contrast between hot/cold objects. Real FLIR cameras tend to be expensive, and the more affordable ones are low-resolution and designed for smart phones rather than FPV video transmitters.
I don't think that putting a light on a drone is going to help much until you reach car headlamp brightness, and even then you might find it's too narrow.
I found this commercial FLIR drone but at under 9 frames per second it's not really FPV, and it still looks expensive.