Optics question. What is a recommended treatment/finish for internal surfaces of lens holders to reduce/eliminate light refraction? Application notes, Lens holder is aluminum and attached to an OEM camera body.
Check with companies that sell parts for telescope building. This is a common thing for builders and the solutions run from simple to complex depending on how much performance you want.
One of the easiest solutions is to cut a fine thread (1 mm pitch or less) with a minor diameter equal to the ID of the fixture. The steeper the thread angle the better. When anodized the threads will act as a light trap.
black anodised is not really good as this is reflecting in the infrared.
I got a black paint from a shop that is supplying amateur telescope builders, this paint has an ordinary use for school blackboards. If mixed with fine particles the black will be "more black".
There is also the ultra-black paint used today on cars instruments, but the primer is near 30€/kg and the paint near 130€/kg.
Make the edges of the lens holder very sharp without deburring! This will yield much less straylight.
Optics question, light refraction reduction
Re: Optics question, light refraction reduction
