External auto focus for thermal cameras?

[Logan]

Hi, began with a silly thought, I did a google search, and surprisingly there's already people do it for visible-light cameras, examples:
https://petapixel.com/2020/10/27/this-external-lidar-device-can-add-continuous-autofocus-to-any-camera/
https://hackaday.com/2014/11/12/an-external-autofocus-for-dslrs/
Since the distance is not sensed by the camera they operate on, they can be used on any camera, including thermal ones.
Auto focus is so rare on thermal cameras, anybody want give these a try?

[Fraser]

I used National Panasonic video cameras in the 1980’s that employed ultrasonic distance measurement and motorised focus adjustment. These worked OK but I think the issue may be the shallow depth of field that thermal cameras can have. A shallow depth of field is very demanding on an auto focus system that does not analyse the actual image being captured.

The thermal cameras that I have with real auto focus use the image being collected and even those expensive cameras are not perfect at getting the focus right every time. Auto focus on a thermal camera is not easy, no matter how you approach it.

[Vipitis]

There is a professional version from DJI as well