In a word, collimation. It's challenging in a telescope, but to get the exact same magnification to be aligned exactly means they will be expensive, or give you a killer headache while your brain...
Type: Posts; User: Bol Tackshin
In a word, collimation. It's challenging in a telescope, but to get the exact same magnification to be aligned exactly means they will be expensive, or give you a killer headache while your brain...