How does a camera lense work different from a telescope?
water_skipper asked:
How does a telescope work different from a camera lense? I’m specifically wondering about magnification. With a camera lense, a longer lense means higher magnification so to get really high magnification it needs a really long lense. With a telescope they just change the eyepiece to get higher magnification and don’t change the length of the telescope.. How is it telescopes can change magnification like that and camera lenses can’t? I asked this question under physics already and didn’t get any decent answers.
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How does a telescope work different from a camera lense? I’m specifically wondering about magnification. With a camera lense, a longer lense means higher magnification so to get really high magnification it needs a really long lense. With a telescope they just change the eyepiece to get higher magnification and don’t change the length of the telescope.. How is it telescopes can change magnification like that and camera lenses can’t? I asked this question under physics already and didn’t get any decent answers.
August 19th, 2009 at 7:58 pm
In a telescope where you can change the magnification it is a reflecting telescope and the eyepiece goes in the side. What you are actually doing is using a small telescope to look at a small part of the captured image and enlarge it for your eye - you are not changing the light capturing ability or enlargement of the over all telescope.
In a refracting telescope with the viewing on the end through lenses, you are using lenses the same way the camera does - adjusting the focal length and viewing the result.
August 20th, 2009 at 6:33 pm
By changing out the eyepiece of the telescope you are essentially magnifying a magnification. The idea is still the same - a longer barrel on the telescope would increase magnification too - but for amateur equipment swapping out an eyepiece is cheaper to manufacture.
August 23rd, 2009 at 9:22 pm
To summarise: a telescope is essentially 2 lenses placed one after the other.
The eyepiece is just a magnifying glass in its simplest form, more advanced ones may have multiple elements similar to a camera lens.
Either will work similarly to a camera lens (in fact you can fit a camera instead of the eyepiece of a telescope), together they provide the effect you see.