Is the diameter of an astronomical telescope same as its aperture or primary mirror?
falling_starz asked:
I mean, when it says 10-cm telescope does it refer to its aperture (which, I think, is the light collecting area right?) or its the diameter of the primary mirror (for a reflecting telescope)?
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I mean, when it says 10-cm telescope does it refer to its aperture (which, I think, is the light collecting area right?) or its the diameter of the primary mirror (for a reflecting telescope)?
April 1st, 2009 at 1:02 am
The diameter is always of the mirror on a reflector or the front element on a refractor. Aperture is a relationship between the diameter and focal length, so a 10-cm scope can be a different aperture depending on magnifiers.
Also, bigger isn’t always better. If you’re in an area with a lot of light pollution, a larger scope will actually make it worse. A better quality 10-cm scope is preferable to a lower quality 15-cm one. If you’re looking for one, avoid metal tripods. Wood tripods reduce vibrations dramatically (great for viewing, vital for astrophotography)