Dumb collimation Q

[Kit-Fox]

Ok i'm sure this is a really dumb and stupid question but whne your collimating your scope do you have the focuser racked all the way in or do you keep the focuser tube flush with the inside of the scope??

its a newt scope btw

[themos]

Best to pull it out enough that it doesn't interfere with the aperture (you can't see it when you look down to the mirror).

[Kit-Fox]

right, I've been keeping the end of the focuser tube flush with the inside of the scope tube. Just everytime i read something on the process its always different advice.

I dont suppose theres anyone in the staffs area who would like to come and give me a demonstration?? I'm sure we can work out some compensation (beer tokens anyone?)

[themos]

if you're checking collimation with a star test or an artificial star then you want the aperture unobstructed.

[TopHouse]

Suppose Oldham is too far for you, having said that I do have a very rare and contagious case of collimation OCD

[Astro_Baby]

I know this is a technica answer but assuming your using a Cheshire or a colicap ite depends.

When your setting the secondary mirror I rack the focuser in enough so that the edge of the focus tube nearest the secondary mirror forms a circlke to set the secondary outline by.

When I move onto the primary mirror I just pull the focus tube far enough back to get a good view and make sure the tube is unobstructed by the focus drawtube. In reality with my Moonlite the focus tube NEVER extends into the scope.

Mostly its a case of whats comfortable for you. Normally when I am collimating I am racking it in and out all the time to get the best view for whetever I am doing at the time.

[albedo0.39]

I always make my fine collimation adjustments with the focuser racked all the way out.

Why ? Well, it actually puts a little bit more pressure on you to get it right. It's all down to parallax error etc and it helps to ensure your settings are as tight as possible.

(unless of course, your focuser goes off axis as you retract)

[Kit-Fox]

Thanks for the offer Tophouse but Oldham might be a tad to far, not in great shape atm with my hip etc so trying to keep everything very local atm.

And to everyone else, thank you for your advice will see how well I can do.