Why is there a brass spacer behind the lens interface?
The UVCorder™ is designed to use conventional C-mount TV lenses that are much lower cost than quartz UV lenses, and in some cases, provide superior image quality. The C-mount back working distance of these lenses assumes that visible light is being imaged. UV light focuses slightly longer than visible light, requiring a thin brass shim spacer so that the UVCorder™ will properly form an image for targets at infinity.
