Quote Originally Posted by BrigandTwoFour View Post
Zoom ratio is the correct term. Internally, it's a standard erector assembly with lenses spaced in a certain way. Manufacturers reuse that erector assembly and change the specs of the objective and ocular lens to set the base magnification level.

For example, take the Meopta Optika6 line. All of them use a 6:1 zoom ratio, and likely the same erector assembly. From that, they produce:
  • 1-6x24
  • 2.5-15x44
  • 3-18x50
  • 4.5-27x56
  • 5-30x56


All of these use the same 6:1 ratio, but adjust the size of the objective and ocular lenses to provide the starting magnification and appropriate amount of light for the higher magnification.
Thank you, that makes sense.


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