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Old 20-11-2007, 09:00 AM
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Satchmo
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Join Date: Dec 2005
Location: Sydney
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Quote:
Originally Posted by Terran View Post
Note that even though the collimation is closer, the focuser ring is way off no matter how collimated it is.

Terran

Your collimation looks almost perfect .

Note how the refelection of the focusser/eyepiece is well centred in the reflection of the primary mirror and all is centred on the actual base of your focusser. The reflection of the eypiece base looks slightly offset in the outline of the secondary because of 'secondary offset' needed in an F5 scope. It will always look this way when you have correct offset. The fact that the physical edge of the diagonal mirror is a little offset is of no consequence to your image sharpness, that only has a slight effect on the eveness of lighting at the edge of the field in long exposure photograpghy.

You probably owe it to yourself to read up more about collimation so you can undersatnd what you are seeing when you look down the barrel.

When you look at a star image and slightly defocus it in and out , does it look round and symmetrical with the secondary shadow centred ? That is about all you need to verify your collimation.

Perhaps the problem is one of your expectations of what you will see on the Moon. You need to get together with another amateur and look through another scope. Why not look for your closest astronomy club.

Mark
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