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Originally posted by janoskiss
Yes and no.
Starkler's advice on collimation I could only take as far as the visual inspection thru the focuser, and it looks OK.
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Meaning you cant see the primary centred in the secondary?
Adjust secondary tilt to remedy.
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Film canisters do not fit in the focuser.
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Perhaps your eyepieces are 0.95inch and not 1.25inch ?
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The star test is a bit hopeless. You can see some fuzzy arcs of circular fringes, and I can't really improve on it at either mirror.
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Means primary mirror collimation is way out.
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In a scope shop I was told to only adjust the secondary mirror when doing the star test, and I should leave the primary alone.
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This bloke has no idea!
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But my not-so-common sense tells me that I should adjust the secondary first until centre of main mirror appears in centre of view at the focuser (easy with a laser) and then adjust the main mirror (so that with a laser the incident & reflected beams follow the same path).
Have I got this right? Then I can try the star test and fiddle with which mirror?
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Pretty much right although a tiny error in hitting the centre of the primary is magnified when centering the return beam at the focuser. This is why lasers alone arent a complete solution for collimating a scope.
It will help a great deal if you centre spot your mirror. (see google).
Once you get this far, tweak the primary mirror for best star test image.