Collimation

[Anthony1979]

can someone tell me what i need to collimate my scope please

[Ruud]

It depends on the telescope. Do you have a Newtonian, an Schmidt Cassegrain or Maksutov?

These videos may help along in the meantime: https://www.youtube.com/results?search_query=collimate+a+telescope

[Anthony1979]

skywatcher 150p..... cant go anything to focus at all

[Ricochet]

Take a photo of your focuser set up with any eyepiece etc that you are trying to use and post it here. Skywatcher scopes come with both 1.25" and 2" extension tubes in the focuser when you only use one at a time. Many new owners are caught out by this. 

[Anthony1979]

[Ricochet]

That looks like it is set up with only the 1.25" adaptor in place and so should be able to focus with an eyepiece.

What happens when you point it at a star and move the focuser the entire length of travel? Do you see a doughnut of light getting smaller towards one end of focuser travel but never focusing or do you see nothing at all? If you don't see anything perhaps it is because the finder is not aligned and you are not pointing at any bright stars. Try in the daytime on the furthest terrestrial object you can see. As terrestrial objects are closer you will need the focuser position to be further out than at night but if you can get it to focus at least you can get the finder aligned before testing at night.

[Anthony1979]

ive just took it out and i can focus now....... ive pointed it at the brightest star but the star has about 4 spikes coming off it is this normal.......... yeah it 1.25"

[Robny]

7 hours ago, Anthony1979 said:

ive just took it out and i can focus now....... ive pointed it at the brightest star but the star has about 4 spikes coming off it is this normal.......... yeah it 1.25"

Yes...this is normal for a Newtonian Reflector, the spikes are caused by the spider veins that hold your secondary mirror in place

[Anthony1979]

Thanks thought i had another problem. Cant wait to take it out properly 

[Anthony1979]

What equipment do i need for collimation when the time comes to do it

[JG777]

One of these https://www.firstlightoptics.com/other-collimation-tools/rigel-aline-collimation-cap.html to get started.

Then, or one of these https://www.firstlightoptics.com/other-collimation-tools/astro-essentials-cheshire-collimating-eyepiece.html

And this guide http://www.astro-baby.com/astrobaby/help/collimation-guide-newtonian-reflector/

Plenty of help here as well if you need it.

[Anthony1979]

thanks

[RT65CB-SWL]

As @Robny said above, the spikes, otherwise known as diffraction spikes are normal. It is when you get oval stars or a slight ghosting effect, (as shown in the image below), then it may/will need collimating.

<---this is an image of Jupiter from my mis-collimated ETX105. 

[malc-c]

To be honest given the OP's lack of experience and knowledge about using a Reflecting telescope, I would't feel comfortable with them collimating the scope.  I would suggest that they join a local astronomical group where someone can take them under their wing and help them get the most out of the scope

[Ricochet]

23 hours ago, malc-c said:

To be honest given the OP's lack of experience and knowledge about using a Reflecting telescope, I would't feel comfortable with them collimating the scope.  I would suggest that they join a local astronomical group where someone can take them under their wing and help them get the most out of the scope

I think a lot of us have learned to collimate reasonably well using online guides like the one linked above.

My collimation equipment is as follows:

1. The red FLO cheshire/sight tube for the secondary
2. A 2x barlow and laser for the primary
3. A short cheshire with the crosshairs removed for checking the primary after 2.

[RolandKol]

Just FYI,

Initially, once you are not sure how and why you need to collimate, l would strongly advice Do Not Touch any bolts of the Secondary mirror.

You can bravely play with The Primary, but NoT the secondary.

But all online manuals will advise you to adjust the secondary also... Do not listen.

Go for secondary once you are sure you need it.

Simple out of focus star test will show you that.

[Tommohawk]

I'm sure you could learn collimation, there are lots of online guides, but don't twiddle anything until you are very familiar with the basic operation of your scope. TBH until you've used it for a while I don't think you'll even know whether it needs collimation. 

 

[Anthony1979]

So should it already be collimated if its new then

[johninderby]

No newtonian ever arrives colimated alrhough small newts aren't as far out as larger ones. It’s the nature of the beast. Just carrying it around can upset the colimation although a small newt will stay in colimation much better than a big one. 

If you buy a newt you will need to learn how to colimate to get decent views but basic colimation isn’t difficult with a bit of practice.

Edited April 29, 2019 by johninderby

[Ledge1962]

I lost a lot of sleep reading about, and watching all the videos on collimation. JG777's advice (above) with the links to the cap, the Cheshire and Astrobaby's guide is what I ended up using and it worked great. While it seems daunting the first few times you do it, it soon becomes second nature and you will find yourself carrying out collimation with ease. 

The members of this site are awesome when it comes to helping out, so I recommend if you get stuck, take photos through your collimation cap (a cell phone does this surprisingly well) and put them on here.  The members can then advise what you need to do to get the scope lined up.  I did and got good advice on a simple process that I was over thinking. 

[Anthony1979]

Alot of people have said i shouldn't touch the secondary mirror is this true

[Tommohawk]

29 minutes ago, Anthony1979 said:

Alot of people have said i shouldn't touch the secondary mirror is this true

if you need to collimate you really need to start with the secondary, then do the primary. BUT the secondary is the more difficult thing to get right. The primary is relatively easy.

So, as I said before, just see how things go before you start fretting about  collimation!

[Anthony1979]

When you say just see how things go what do you mean.... Does that mean i can't really use it till its collimated... Sorry for the stupid questions but i really don't want to mess it up because its new

[Tommohawk]

24 minutes ago, Anthony1979 said:

When you say just see how things go what do you mean.... Does that mean i can't really use it till its collimated... Sorry for the stupid questions but i really don't want to mess it up because its new

There is no such thing as a stupid question! If this is all new for you you cant possible know all the answers!

All I meant was that the scope should be useable straight out of the box. It may not be perfect, but you should be able to reach focus with an eyepiece and see something! When you get some clear sky, find a target (NOT THE SUN OBVIOUSLY!) and just see what you can see. Stars in the central field should be round, although with a newtonian like the 150P the stars at the edges will have coma - Google that. 

If you can see the moon that's always a good target, but not up until the early hours at the moment. Jupiter is also visible, but again early hours. Mars is also visible early evening but very low and very distant to not a great target at the moment.

If you dont have Stellarium software you might want to get that too - its a free software download that shows you whats visible in the sky at night, and you can enter your scope and eyepiece details and get a simulation of what your actual view will be. 

[barkis]

It is good Idea to line up your little finder scope with the main telescope too. This can be done in daylight. Put your  lowest power eyepiece into the 150's focuser and look for a target some distance away from you, a very distant chimney pot or suchlike.  Once you have the target in the centre of the eyepiece, adjust your finder until you have the same object in view.once you have both Scopes aligned, replace the low power eyepiece with a higher power one, being careful not to move the scope accidentally.  If the now magnified image is still centred in the main telescope, look through the finder to check that the target is still there in the centre, I not, carefully adjust the finder by manipulating the screws around the tube, slacken one slightly before tightening another, you will need to experiment with this process until you understand what effect slacking and tightening the screws are having on the finder.  

Centering the higher mag. Image in the finder, is making the line up of  the scopes more accurate, and will help at night when using the finder to locate objects in you main instrument.

It will help a great deal if you manage to tune them together. The finder has a wider field of view than the 150, so the finder will help a lot.

Ron.