Anyone need to center-spot or clean their primary mirror?

[iceman (Mike)]

Hey guys.

If any of you dob/newt owners are looking to centre-spot or clean their primary mirrors in the coming weeks, it would be great if you could take photos and document the process.

We need a "how-to" article on the site for these common tasks, so it would be nice if someone had the time and inclination to write one up!

Thanks!

[asimov (John)]

Yep. I'll be spotting my 12.5" mirror next week I would say..I'll take a few pics & do a quick write-up.

[frogman (Anthony Lord)]

i will be interested to see how its done
secondry as well ?

[asimov (John)]

Well....I'd like to spot the secondary, but I'm not really game, so no....I dont reckon.

[Starkler (Geoff)]

Heres a few to get somebody started

I took these during my last mirror cleaning exercise.
No prizes for guessing which ones are the before and after pics

[iceman (Mike)]

Sonuds good John, thanks!

Anthony, I don't see any reason why you would want to (or need to) spot your secondary!??

[asimov (John)]

Hey Geoff.... What kind of centre spot is that? I know it's one of those hole reinforcement rings....but can I see some sort of pattern or something on the ring itself?

[asimov (John)]

Mike....re: centre-spotting the diag. From what I've read, some people work out the off-set needed for the diag. & then spot it at that measurement....ie if a 2mm off-set is needed, put the mark on the mirror 2mm off-centre.

I wont be bothering to do this though. I think I can guess a 2mm off-set of the diagonal using me lil' peep-hole-do-hickey.

[Starkler (Geoff)]

Originally Posted by asimov

Hey Geoff.... What kind of centre spot is that? I know it's one of those hole reinforcement rings....but can I see some sort of pattern or something on the ring itself?

Just me scribbling on it in hopes a pattern would make it more easily visible.
It didnt help.

[asimov (John)]

Oh, ok....thought it might have been a brand new collimation technique!