From: "Dwight K. Elvey" 
To: atm{at}shore.net
Reply-To: "Dwight K. Elvey" 


>From: "A. Suykerbuyk" 
>
>>Collimation by any means against a center mark presumes it is at the
>>true optical center. If it isn't, collimation will be off, as can be
>>detected in a star test. I too would like to know if this is common.
>>>
>I wonder if a star test on a real star should not be regarded as the final
>test for collimation, especially when one is using a fast mirror.
>This makes the use of lasers etc. a little bit easier.
>When one is using a artificial star the scope will be horizontal, the
mirror
>will not be
>supported at its back, and collimation will be off when the scope is in
use.
>

Hi
 The objective was to find the optical center of the
mirror and not to tune for final use. Most telescopes would need to be
readjusted for the range of angles used. A thin mirror might also warp a
little, changing the effective center.
Dwight

>Regards,
>Adrie Suijkerbuijk.
>
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>
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