I recently purchased a Seek RevealPro Thermal Camera, which boasts a 320 x 240 thermal sensor with >15 Hz frame rate at an incredibly affordable price.
One of the only issues that I have with this camera is that it comes with a fixed 32° field-of-view lens. This is OK for general thermal inspection, but it’s a real disadvantage when trying to use the camera for close-up work to assess dissipation on printed circuit boards, or for identifying a faulty or undersized component. On the opposite side of the distance range, the 32° FOV lens makes it difficult to see and measure the temperature of objects at a distance, or of smaller objects at normal distances.
I thus decided to build magnifying (“macro”) and close-up (“telephoto”) converters for the RevealPro. I’m passing along information on my designs in hopes that others will find it useful. You can read the post at http://uvirimaging.com/2018/03/05/thermal-camera-diy-macro-and-telephoto-converters/ and get detailed instructions in the following whitepaper: Diy-Thermal-Camera-Telephoto-Converter