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Old 03-02-2010, 10:17 AM
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Satchmo
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Join Date: Dec 2005
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Quote:
Originally Posted by MuntiNZ View Post
Yeah but your comparing a 10 incher to a 12 incher.
The bigger one will usually be better even if the big one has optics not as good as the smaller one.

Apature rules mate.
Larger apertures only ( for example) show fainter stars only if the light is properly focussed in to the Airy disc. Theory shows, that at a wavefront error ( primary spherical ) of 2/3 of a wave / 1/3 surface accuracy , a superb telescope of _half_ the aperture will have the same visual magnitude limit.

Bright diffuse objects will benefit from extra aperture even't if it isn't quality, but the higher contrast of a smaller more accurate system will really help in spotting faint galaxies.
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