Collimation phobia

[Kenny]

I've got two Newtonian telescopes.

• An unbranded "Event Horizon" (actual brand unknown) one with a 6" mirror, dodgy equatorial mount, purchased from a manufacturer somewhere in the far east via eBay (is this too much confessing? I was a complete newbie!). Has stood me in good stead though.
• An Orion Skyquest 8" dobsonian which was given to me a few years later. I use this as my main telescope these days as it's so quick and easy to set up and manoeuver about.

I'm ashamed to say, neither of the two scopes have ever been collimated in the time (7+ years) that I've owned them. 

I've watched the best that YouTube has to offer and am willing to give this a go now. Two questions come to mind, one simple, one scary:

• I don't own a laser collimator. Is it important how much I spend on one (keeping budget in mind)? I see that considerations are variable brightness, laser-self-collimation screws, angled "target". Can somebody recommend a good, but reasonably priced, one?
• Now for the scary bit... neither of the telescopes have a centre dot on the primary mirror. I nervously presume that what I actually need to do is remove the primary mirror, clean it, and fix a centre dot, before re-assembling then collimating as per YouTube?

Gentle, supportive guidance appreciated.

[Kylee]

Hi Kenny

I was really terrified of doing this but since I purchased my laser collimator it's really easy. Don't be scared....I can collimate my scope in minutes now.

I'll check out my collimator and let you know what brand it is   

[Kylee]

You definitely need the dot to be sure you are truly central 

[MarkH]

I have the same phobia, even though I've had it less than a year. It's never had a bash so it should be ok. But from an engineers point of veiw if it ain't broke don't fix it. If I ever do have a go I will buy aset of bobs knobs first, I'm not getting an allen key anywhere near that lens.

[MarkH]

Aparently it's easy to collimate with a three aparture focusing mask........cue Duncan

[Carole]

This is a really good website and explains step by step.  If you don't have to collimate the 2ndry it's not too difficult, and even if you do it explains all that too.

http://www.astro-baby.com/collimation/astro%20babys%20collimation%20guide.htm

[Kylee]

I can show you if you have your kit available at some point. 

If you are going tomoz to the pub I'll bring my collimator for you to look at?

Kylee

[The Thing]

BTW for those who don't know MarkH has a SCT which is a different beast to collimating a Newt. MarkH DO NOT BUY A LASER COLLIMATOR!, don't work with SCTs/

[Kylee]

My replies were for Kenny as he started the thread and has a couple of Newtonians. Wasn't advising Mark H on his collimation techniques with his scopes.

[Mac]

BTW for those who don't know MarkH has a SCT which is a different beast to collimating a Newt. MarkH DO NOT BUY A LASER COLLIMATOR!, don't work with SCTs/

Not any more. 

http://www.hotechusa.com/category-s/23.htm

Mac.

[Mike]

Holy cow did you see the price?!?! 

[RobertM]

Collimation... If it were only that simple to get it right...

The trouble with using a laser is that there are actually many possible positions of the primary/secondary that make the scope look like it's collimated.  To do it properly it's a bit more complicated depending on how fussy you are but if you're not then a simple primary/secondary tween may well be all that's required.  I would also strongly advise getting a Cheshire as well, they are quite cheep and show more than a cheap laser can as well as giving you a method of double checking.

Here is a good link to getting it right courtesy of Astronomy shed http://m.youtube.com/watch?v=zd-fl9SEYHw&desktop_uri=%2Fwatch%3Fv%3Dzd-fl9SEYHw

HTH
Robert

[The Thing]

Holy cow did you see the price?!?! 

That's why I do it myyyyy waaaayyyyyy (all togther now...)

[MarkH]

Holy cow did you see the price?!?! 

That's why I do it myyyyy waaaayyyyyy (all togther now...)

 

[Kenny]

Here is a good link to getting it right courtesy of Astronomy shed http://m.youtube.com/watch?v=zd-fl9SEYHw&desktop_uri=%2Fwatch%3Fv%3Dzd-fl9SEYHw

Astronomy Shed was the series I was referring to when I said "the best of YouTube". He's a bit anal about his collimation (that's not a euphemism) but it is an excellent guide.