Centering secondary mirror

Equipment Reflectors Collimation
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Max Gillet avatar
Max Gillet avatar
Hi !
I need to collimate my newton (200mm f/4) and I saw somewhere that the secondary mirror need to be a little bit decentered for telescope with big aperture (like f/4). Is it true ? If yes, why ? And is it necessary even with a barlow 3x (f/12) ?

Clear skies,
Max
Engaging
Andrea Alessandrelli avatar
Andrea Alessandrelli avatar
You can check a thread I started a couple of years ago on Cloudynights: https://www.cloudynights.com/topic/581915-fast-newton-secondary-offset-looking-for-feedbacks/

it has been very useful to me.

CS

Andrea
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