What is collimation?

[gobes]

As most are aware... I'm new to astronomy, having just got my first telescope.

I've seen a lot of talk about collimating... but I'm not entirely sure what this means (I gather it's something to do with aligning the lenses/mirrors properly)!

Can anybody give me a quick heads up on what exactly collimation is? Also... how would I know if my scope requires collimation?

Many thanks.

[storebror]

Here is quite a good video on collimation and how to carry it out when it's necessary:

http://www.andysshotglass.com/Collimating.html

[acey]

Collimation? Don't even ask. Just enjoy the views. After a year or so you can try fiddling to make things look even better. But be warned that once you start fiddling you might never stop. Absolutely perfect alignment of the two mirrors in a newtonian is impossible - half decent alignment is pretty easy. If you must, use a punctured film cannister or collimation cap and check you've got half decent alignment, then leave it at that. If slightly out-of-focus star images at high power are little circles with black holes in the centre then everything is fine.

[The Warthog]

As Acey said, don't worry about it for now. I used my Meade 4500 for three or four years before I knew what collimation was. Learning about it didn't make me happier. The first time you try you should have a trusted friend and a big box of Ibuprofen handy.

Just have fun with your scope for now. It's probably not that far off.

[kniclander]

guys, I know your comments might be a bit tongue in cheek but in reality -

if the OP has a fast newt he needs to know how to collimate it; and

if he has a slow newt then collimation should hold no fears because it doesn't have to be too accurate.

tbh gobes, if it aint broke don't fix it - as Acey says, if you defocus a bright star and its round and regular then you're ok ; if it isn't, then don't be afraid to tinker.

another really good resource is Astrobaby's collimation guide - if you do a search on the forum you should find it.

[Doc]

Collimation is never perfect you can fiddle for ages and still not get it perfect.

There is so many obstacles that can make collimating a dob very frustrating. Just get it as good as you can and enjoy the views.

[Astro_Baby]

Beg to differ on this one - collimation is a comfort when the sky is cloudy - a Newtonian owner can with only a few simple tools keep themselves amused for hours with collimation.

Globes - your right - its a process of aligning the mirrors in a refelecting telescope. A small reflector needs less than a large one as a general rule. Fast reflectors ( short tube length ) need more accurate collimation than long, long ones.

My advice would be leave well enough alone until you have to collimate. I had to as my youngest son decided to undo the spider vanes on my scope

It all started from there and within a few weeks all my hair fell out, I went insane, had sleepless nights but subsequently learnt enough to write a guide about it :)

Once you have done it a few times it holds no terrors BUT be warned once you start it becomes a bit compulsive and its a good way to develop an Obsessive Compulsive Disorder.

I'd also be wary of the video on Andys Shot Glass - its a good starter to give you the basics but he doesnt mention offsets which can drive the begginer to collimation mad as a fast scope needs an offset which isn't covered in Andys video and while the video is a good primer and for a long scope all you'll ever need a fast scope has extra issues.

[gobes]

Many thanks for all the advice.

I'll definately be leaving well alone for now. I'm a bit of a Frank Spencer when it comes to anything involving screws!