Sciencemadness Discussion Board

Optics/magnification practical question/field test

math - 12-7-2013 at 01:01

Hello,

I'd like to know if there is any test I can do to gauge how many times does a binoculars or telescope magnify, so to see if it is an 8x, 10x etc.

I was thinking about using a ruler at different distances that the telescope can focus on, or yet using something which is of human-treshold visualizable size, though I can't square out a working method.


Thank you :)

bfesser - 12-7-2013 at 09:22

Are there any markings at all on your binoculars or telescope (other than "Made in China")? If so, type them out or attach a photo, and I'll either tell you how to interpret it or look up the magnification. If not, I'll have an excuse to dig out my optics books.

math - 12-7-2013 at 10:02

Quote: Originally posted by bfesser  
Are there any markings at all on your binoculars or telescope (other than "Made in China")? If so, type them out or attach a photo, and I'll either tell you how to interpret it or look up the magnification. If not, I'll have an excuse to dig out my optics books.


Yeah, there is the classical AxB number where A is the magnification and B is the larger lens diameter in millimeters.

However I'd like to know if there is a simple test I can perform to check if that 10x30 I have (or anything like that) is really a 10x magnification, since measuring the 30mm larger lens of course is not the problem.


Thank you