There are a lot of affordable optics out there, but it takes an investment for a good thermal monocular. With spectacular advances in thermal technology over the last few years, these remarkable ...

[David Prutchi] writes in to tell us about his recent experiments with building lenses for thermal imaging cameras, which to his knowledge is a first (at least as far as DIY hardware is concerned).

How Thermal Imagers Work and How to Hide from Them. The basic principle of operation of all thermal imaging devices.