I used a 16mm camera to project images.

I used an Eclair NPR 16mm camera as a lens projector. Lens projectors are used by manufacturers and rental houses to analyze the performance of a lens. I used a Vlad test target to project an image with a lot of fine detail in it.
This method allows me to see the sharpness of the lens, if there is vignette, distortion, areas of the image that look blurry, and stuff like that. This is a pretty cool concept that may be helpful for other people.