Field guide
Guides: thermal imaging and night vision on a phone
Straight answers about thermal imaging, infrared and night vision — what a phone can really see, and what needs hardware.
Does the iPhone have a thermal camera?
No iPhone has ever had a thermal sensor, and the iPhone 17 does not either. Here is what the infrared hardware in your phone actually does, and what you can still get out of it.
Night vision vs thermal — which one do you actually need?
Night vision amplifies the light that is already there. Thermal imaging senses heat and needs no light at all. They fail in opposite conditions, which is why the answer is almost never "whichever is cheaper".
How does a thermal camera work?
Everything warmer than absolute zero glows in infrared. A thermal camera collects that glow with a germanium lens, measures it with a microbolometer grid and paints the result in false colour.
Why is night vision green?
Night vision is green because of the phosphor screen inside an image intensifier tube — and because the human eye pulls more detail out of green than out of any other colour.
How do night vision goggles work?
Night vision goggles amplify the little light there is, roughly 20,000 times, using a photocathode, a microchannel plate and a phosphor screen. Thermal imaging is a different technology entirely.
Thermal camera apps for iPhone, compared
iPhone thermal camera apps fall into two groups — companion apps for a clip-on sensor, and live camera effects. Knowing which you are downloading saves a lot of disappointment.