True “no light” night vision.
I used to work for a company that made night vision stuff for the military (including rifle scopes).
We made “image intensifier” which is the green stuff you see in old movies, it amplifies the light so much that headlights can do permanent vision damage if they don’t have a very fast limiter built in (which old ones do not). But “green night vision” could be used even with only a very tiny bit of moonlight or other slight ambient light.
But then we moved into thermal which is pretty amazing. Firefighter cameras, gun scopes, long range telescopes, all kinds. Yes it is black and white but can be very detailed with a good quality lens and sensor. We even started adding colors for the different heat levels so firefighters would know what is most dangerous. The main benefit of the firefighter cameras is that even thick smoke is pretty much invisible in this spectrum, can see right through it. Of course that is all commonplace these days, you can get a FLIR add on for your phone or a handheld one for checking heat escape from your house.
A real common use back then was the power companies would have them in their cars for checking transformer heat.
Then of course, when you work with a bunch of jokers, you find out that thermal cameras can:
See through black plastic bags and often clothes, especially if there are large warm round things under a shirt.
NOT see through plexiglass or glass in most cases (it is jet black)
Detect who farted
See hand prints and butt prints for 30 or so seconds after contact
Make some pretty scary looking images when you use cold water (looks like blood)
These images are from 20+ years ago, it has come a long way since then but even then, it was pretty impressive
The only camera they let me bring home to play with (aka the only one worth less than $10,000) the video output was fairly low res compared to the built in screen, and the camera I hooked it up to for recording (360i camcorder) was as well, so doesn’t do it justice, but gives an idea of the capability. The images captured from a military long range camera (4’ long lens) were incredible but those were not allowed to leave the building.
Butt imprint on carpet floor (with suspected gaseous release)
Building taken in complete pitch black (even the clouds are slightly warmer than the sky and stand out). This was a warm summer night, had it been cold, the image would essentially be inverted, brick building and grass etc cold/dark and windows warm/white.
Fun with ice cubes and cold beer
Parking lot cold spots where the cars blocked the pavement from the sun, and some hot engines glowing. This lot is lit up with overhead lights, but that means nothing in the thermal IR range (other than the heat the lights put out which is only visible on the lights themselves)
Many of the others I have are not suitable for posting here 
