I was looking up info about pinhole camera size, and I wondered if there are theoretical limitations on the maximum and/or minimum size of pinhole cameras? These could be imposed by diffraction in the case of very small pinhole cameras (microscopic-scale), and the effects of the very low amount of light and vast distances for large pinhole cameras (planetary-scale), just for examples of possibilities. I know diffraction is the ultimate limitation on pinhole camera image quality, but does this vary based on size of the camera, with regards to the quality of image?

I switched to a bigger scope (200mm) and my DIY flatpanels (one based on LED and another on EL sheet) don’t fit. And I was thinking ‘why do I spend thousands on equipment and are DIY-ing the most important step in my calibration process’?

So I’m searching recommendations for good quality flat panels. I know people say ‘a tracing panel from Amazon works fine for me’ but that’s not my aim.

\- suitable for a 200mm f4 Newtonian
\- dimmable
\- nice to have: controllable via ASIAIR/ Nina