Need collimation?

[TerryJ]

Hi, here's a quick shot down the eyepiece, still being  very new to this, do the experts here think I need to collimate?

Scope is Celestron Astromaster 130.

Terry.

[wookie1965]

Yes it needs collimating use this site. 

http://www.schlatter.org/Dad/Astronomy/collimate.htm

[Dave In Vermont]

Indeed - it certainly does need collimating - STAT! The poor thing! But don't freak out - it's always a worry the first time, but then it's like riding a bicycle!

Below you'll find what is arguably one (or 'if not THE') of the best collimation-guides out there: Astro_Baby's Collimation Guide. Unfortunately no longer findable on the web (her site is down), some of us stashed copies away for just this purpose. And she is a member here as well. So take a deep breath, be seated, and give it a read. We're here to help you if and when needed. Here you go:

 

Astro Baby's Collimation Guide.pdf

 

The most difficult part of collimation is understanding exactly what, and why, your doing this and what exactly you're trying to accomplish. It will come to you. Rather like an epiphany!

Enjoy!

Dave

[John]

If the camera lens was centered on the drawtube then the collimation looks like it needs adjusting. If the camera lens was not quite central though, this might not be the case.

 

[barkis]

As John said, your eye, or camera needs to be precisely  centred on the optical axis of the telescopes focuser, 
in order to get good idea of how good your Collimation is, or not as the case may be.
The process could be described as a simple one, but it actually caused  many to tear their hair out in frustration.
The thing to do is Identify the elements you are looking at,  because what you are seeing are multiple reflections
of the parts that make up the optical train of your telescope, they can be puzzling. There are many ways to approach collimating a scope.
Some good advice has already been provided in the thread. Choose one, and have a go at the job. If It needs doing, it has to be done right
for your instrument to perform at it's best, seeing conditions prevailing of course. Scope temperature, earths atmosphere, can play a role in poor 
images. In these warm summer  temperatures, allowing your scope to cool to ambient temperature  is a good thing to do.
Good luck, and try not to get too frustrated, it will get easier as you become familiar with the process, but initially, it can be a Mare.

[TerryJ]

Hi all, 

Thanks for all the great advice given here. Think I will spend Sunday reading and rereading then giving it a go.

Terry 

[Ally8446]

This is what you're looking to achieve. 

[MarsG76]

As stated above... hard to say.. you would need to take the picture (or look) down the focus tube in the dead center to know for sure... But most likely you do need to, I need to recollimate every time I set up my dob.

[JOC]

On ‎20‎/‎06‎/‎2017 at 21:04, Ally8446 said:

This is what you're looking to achieve

That's a good set of pictures.  However, it's easier to say that now that I've done the process once.  Until I stuck a Cheshire in the EP holder and took a look at things myself and (as Dave in Vermont noted) realised what I was looking at and then it dawned on me how it all hung together as a functioning unit, I was a bit non-plussed.  Nothing like doing it to make things make sense and a Cheshire is certainly the way forward IMO - I used the Laser afterwards just for the satisfaction of seeing it bounce back accurately to know that I'd done a good job.  TerryJ it is also well worth watching some UTube videos of people doing it to realise that things can get very loose and not to worry.  I wouldn't follow UTube instructions - use Astrobaby's guide for those, but watching videos of folks shifting their mirrors will give you the confidence to try if you are very iffy about undoing nuts as I was.

[Ally8446]

4 hours ago, JOC said:

That's a good set of pictures.  However, it's easier to say that now that I've done the process once.  Until I stuck a Cheshire in the EP holder and took a look at things myself and (as Dave in Vermont noted) realised what I was looking at and then it dawned on me how it all hung together as a functioning unit, I was a bit non-plussed.  Nothing like doing it to make things make sense and a Cheshire is certainly the way forward IMO - I used the Laser afterwards just for the satisfaction of seeing it bounce back accurately to know that I'd done a good job.  TerryJ it is also well worth watching some UTube videos of people doing it to realise that things can get very loose and not to worry.  I wouldn't follow UTube instructions - use Astrobaby's guide for those, but watching videos of folks shifting their mirrors will give you the confidence to try if you are very iffy about undoing nuts as I was.

Thing is, I don't think anyone could have been more nervous when I started collimating. Once you actually understand what you're looking at, it's just so simple. These days I put the whole lot WAY out of collimation just to do it again.  Yes,  I'm that sad ?

[popeye85]

1 hour ago, Ally8446 said:

. These days I put the whole lot WAY out of collimation just to do it again.  Yes,  I'm that sad ?

ME TOO!! although I always panic in case I won't be able to get it back!

[wookie1965]

Took me two days first time I gave up first day did it the next after reading and rereading how too's. When I got my 200p completely stripped it cleaned the mirror flocked it did the secondary mirror mod put it all back together, collimated it in 10 minutes tops just takes practice. 

[JOC]

It is very reassuring to read that I wasn't alone in feeling about doing it to the point of prevarication and avoiding the job.  I thought it was just me!

[TerryJ]

Thanks for all the good advice. Followed astrobabys instructions. Was nervous at first but took the plunge. 

Managed not to break anything and stopped when I thought it looked ok.

Will do again soon.

Thanks again.

Terry

[JOC]

Well done Terry - doesn't it feel fearsome when you undo those nuts for the first time?

[popeye85]

On ‎23‎/‎06‎/‎2017 at 18:22, JOC said:

Well done Terry - doesn't it feel fearsome when you undo those nuts for the first time?

that's one way of phrasing it I suppose!

[TareqPhoto]

Just a quick question which is related to this topic somehow, apologize me if i should ask somewhere else, but it is just quick direct questions i swear.

What is collimation? or let's say when do you need to use collimation or why to use collimation? i will not ask how, that i will find out later and find articles or posts, but i want to know the basic thing about it, so i want to know how important it is and for/with which scopes it is needed.

[alacant]

On 9/7/2017 at 20:58, TareqPhoto said:

What is collimation?

Hi. It's the name given to the process of aligning mirrors and lenses.

 

On 9/7/2017 at 20:58, TareqPhoto said:

when do you need to use collimation

When you are dissatisfied with the images your instrument produces. HTH.

[TareqPhoto]

5 hours ago, alacant said:

Hi. It's the name given to the process of aligning mirrors and lenses.

 

When you are dissatisfied with the images your instrument produces. HTH.

Ok, so it is only done after i check out the mirror scope i will use, if it is good without collimation then i don't need to do, if there is something wrong or as you said dissatisfied then i should collimate it?

[wookie1965]

You can do a star test to see how good your collimation is, but if you are getting good views I would leave it alone until you are not.

Here is a youtube video 

 

[alacant]

6 hours ago, TareqPhoto said:

or as you said dissatisfied then i should collimate it?

Yeah, exactly that. You could always do the star test as wookie suggested. If you can see how to do it just by looking at it then you'll be fine collimating. Otherwise, there are so many confusing guides as to encourage me to make this post... HTH.

[TareqPhoto]

Good you reminded me about it, so i think i should add one with the scope i will buy, a Mak one, in all cases if i will need it or not at least it is there available for me, not expensive though.