While working on the improved actuators for SMMB, I wanted to be able to perform some quantitative experiments to design the thermal transfer of the controller board and enclosure. I figured that feeling with my fingers probably wasn’t scientific enough to make consistent progress.
Enter an inexpensive Chinese thermal imager, which you can find for under $300 from time to time. A non-affiliate Amazon link: https://www.amazon.com/gp/product/B07BDJZ845
It has a resolution 220×160, reads up to 300C and being intended for construction inspection has at least a little software support for reading out actual temperatures and capturing images for reports. The only downside is the focal length. It really can’t focus on anything less than about a meter away. That isn’t too great for PCB inspection.
Enter this eevblog thread, describing at least one person who added a lens for a macro mod. I gave it a try, getting an appropriately specified laser cutter lens from Amazon: ZnSE w/ approximately 100mm focal length labeled as “Laser Engraver”. A non-affiliate link for the exact one I got is: https://www.amazon.com/gp/product/B01DP2HSAY
I could have 3d printed a fancy lens mount, but decided I would see how well a quick and dirty hot glue gun job would work:

And the answer is pretty good — I can resolve individual 0603 components on the board just fine.