What Is the BEST Resolution You Can Get With a Thermal Camera? Testing the Thermal Master P3.

Photo: Rhett Allain. A dog in infrared (using the Thermal Master P3 thermal camera).

You know I love infrared cameras — and so do you (or at least you should). These things detect wavelengths of light emitted by object with temperatures from 0 C to over 100 C — that’s the temperature of stuff around you. So you can see all this stuff that just glows. It’s so awesome.

For instance, look at that dog in the top image. You can see that his tongue, nose and eyes are warmer than his furry fur. Of course what you can’t see is that is a good boy. Yes he is.

So, when Thermal Master sent me the new P3 thermal camera it seemed like a great opportunity to look at resolution. Here’s what I’m going to do. First, I’ll give a review of angular size (that’s important here). Then, we can look at the resolution of different cameras. Finally, I will calculate the theoretical maximum resolution.

Angular Size and Resolution

If you hold out your thumb at arms length, it can cover up the moon. Of course your thumb isn’t as big as the moon — but at that distance, they have about the same angular size (your thumb might vary).

Our eyes and our cameras don’t measure the size of things but rather their angular size (let’s use θ for this) where the field of view for a human eye is…