Get a copy of What If? 2 and Randall’s other books at: https://xkcd.com/booksMore serious answers to absurd questions at: https://what-if.xkcd.com/If you poi...
Is focus to infinity that different for these types of scopes compared to a conventional camera which focuses to infinity after a couple hundred metres? I would have thought the draw back would be the focal lengths giving you a very small area in frame.
Focal length and aperture both affect how much focus matters.
Also with most regular cameras, from what I’ve heard they actually have their max focus slightly past infinity to account for thermal expansion so the general advice for doing astrophotography is to focus on the subject, not just whacking it to infinity.
Those spy satellites are focused at the distance of earth. Hubble is focused at infinity or near-infinity.
You’d just get some really blurry images.
Is focus to infinity that different for these types of scopes compared to a conventional camera which focuses to infinity after a couple hundred metres? I would have thought the draw back would be the focal lengths giving you a very small area in frame.
Focal length and aperture both affect how much focus matters.
Also with most regular cameras, from what I’ve heard they actually have their max focus slightly past infinity to account for thermal expansion so the general advice for doing astrophotography is to focus on the subject, not just whacking it to infinity.