This is a model I designed for a friend who was using a FLIR Vue Pro IR infrared camera to film hummingbirds for biological research projects. The camera itself is more designed with airborne applications in mind, so the camera is pre-set at the factory to a fairly long focal length. If you want to manually adjust the focus for any reason, say to use it on the ground, you need a special tool, and why buy when you can print??
I've printed this out of PLA on a Prusa and also in resin on a Formlabs Form 3 SLA printer. The FDM model I did lying on the flat front face, no support required; the SLA model I printed at an oblique angle and added a small hole to reduce suction on the resin tray. Both models held up well in the field and allowed for efficient on the fly adjustment of the camera focus. This tool is designed to be easy to hold and adjust, and also so that nothing blocks the camera field of view during focusing.
This model has been tested/works with the FLIR Vue Pro/FLIR Vue Pro R camera.
The author hasn't provided the model origin yet.