>>4229340the subjective benefit of more megapixels decreases as the number of megapixels increases.
you do not need +4mp. you need to use the correct optics for the job. a vintage 300mm is a photographic lens, meant for work where the thing is more important than its details and detail is a luxury flourish rather than the subject, and the subject is within medium distances. if you want a highly detailed moon photo with a photography lens, you will end up spending a ton of money on something like a sony 200-600 or that $8000 olympus supertele. camera lenses accept numerous aberrations so they can do things like change focal lengths and apertures and perform well enough at all of them, and it doesnt matter because camera sensors are typically larger with larger pixels.
telescopes however are able to resolve smaller, sharper details than camera lenses at the cost of fixed focal lengths, fixed aperture settings, and minimum focusing distances measured in tens of meters (usually around 30-40m). they were designed for this and are more cost effective. the camera you need for a telescope is about $180, with a sensor the size of a phones, and 12 whole megapixels. its not the number of pixels, but how big the pixels are relative to the details and optical aberrations. for a telescoe these are small and smaller.
