How can you determine the focal length of a telescope?
Posted April 18th, 2010 by admin 1 Comment »
Brack_871 asked:
I have a refractor telescope and I am trying to figure outs it focal length. It is an old Zeiss Telescope and I have no literature on it. Here is what I know:
I have a refractor telescope and I am trying to figure outs it focal length. It is an old Zeiss Telescope and I have no literature on it. Here is what I know:
The diameter of the front lens is approximately 100 mm.
The approximate llength of the telescope from lens to the back is about 4 and 1/2 feet.
Anyone out there able to help me with this?