Advanced Newtonian Collimation Idea

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Re: Advanced Newtonian Collimation Idea

Postby Dion » Wed Jan 06, 2021 11:26 am

Cirrusc74 wrote:Hi,

so newbie question here, having just got a newtonian, and I am familiar with the normal collimation techniques using a cheshire or laser, but having just watched the video a couple of times now, i'm scratching my head a bit..

so after using the camera to accurately centre the secondary mirror to present a circular image under the focuser, you then in the next stage you then just move the secondary to get the primary centre spot in the centre of the image...

doesn't that defeat the object of getting a properly centered secondary for accurate collimation? undoing the fine tuning youve just done or am i missing something...

Also take into consideration I did this, 'years' ago and very few people were pushing the boundaries like this, also note it is titled 'idea'. I have since been contacted by a couple of quite respected people who have said this whole 'idea' is actually bang on. Firstly you are aligning the secondary to the focuser as accurately as is possible to the layman, many shop bought reflectors will be a fair amount out in that alone. Also bear in mind that you did this simply using brain, eye and a reasonable, but not scientifically built webcam. After centering the Primary and then adjusting secondary after this, don't forget that you may be only moving the secondary by tiny amounts that may not be detectable by the eye.

Some of the subjects in the shed are getting old now but there are people in here who were seriously pushing the boundaries back then, including imaging deep space objects with webcams!

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