2007-02-22 02:25:20 · 4 answers · asked by Chandana 4 in Science & Mathematics ➔ Physics
The size of the real image formed by the objective is proportional to its focal length, so it is desirable to have a long focal length there. The eyepiece functions as a magnifier, forming a virtual image. Magnification is inversely proportional to focal length, so a short focal length provides more magnification. The overall magnification is the objective focal length divided by the eyepiece focal length, so if the eyepiece had the longer focal length, the image would appear reduced. This is a well-known effect to anyone who has looked through the wrong end of a binocular.
2007-02-22 03:12:45 · answer #1 · answered by injanier 7 · 0⤊ 0⤋
For magnification. The way the optical formulas work out, the magnification is the focal length of the objective divided by the focal length of the eyepiece/
2007-02-22 02:31:46 · answer #2 · answered by Gene 7 · 0⤊ 0⤋
for a refractor a 3" f/12 FL = 36" for a reflector 6" mirror f/8 FL = 48"
2016-05-23 22:56:56 · answer #3 · answered by Anonymous · 0⤊ 0⤋
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2007-02-23 07:33:37 · answer #4 · answered by Anonymous · 0⤊ 0⤋