How do I know its collimation time?

[Manok101]

What are the signs your scope needs collimation?

[Pete Presland]

do the star test when you are observing and you will know if it needs attention or not

[Moonshane]

the signs are that you begin to consider an observing session and put your scope outside. only after collimation (of at least the primary) will you get the best visual results from your scope.

I collimate both my newtonians before each use as it takes as long to check (which you should certainly do each time) as to adjust.

[umadog]

If stars look asymmetrical then it's definitely time to collimate.

Your 10" is <f/5. At those focal ratios, every observing session should be collimation time.

[kniclander]

whenever it's cloudy it's collimation time...

[Manok101]

How badly could I mess it up if I do it wrong?

[AndyH]

whenever it's cloudy it's collimation time...

[umadog]

You won't mess it up. Just spend an hour or two learning how to do it and it will all make sense. Once it makes sense it will seem easy and straightforward. Just make sure you have suitable tools before you start.

[Moonshane]

the main thing to avoid mishaps is collimate with the tube almost horizontal. then if you do have an accident (drop a tool or nut) then it will not cause any / as much damage.

it's a routine and simple operation once you get your head around it so don't worry. I can collimate both my newts in about a couple of minutes max.

[Macavity]

Zero in on a bright star at highish power. Check the effects of in-focus and out-focus.

If the overall pattern looks e.g. "off-centre", I'd worry about the collimation?

[Manok101]

The reason I was asking is, the stars don't look like points, and I thought they should? Edit: they don't look like points when using my 28mm 2" eyepiece.

[John]

They should look like points in the center of the field of view at least. Towards the edges the stars will show some distortion - probably caused by the 28mm 2" eyepiece.

If stars don't look like points even in the center of the field of view, what do they look like ?.

[stolenfeather]

whenever it's cloudy it's collimation time...

I'd agree with that!

Isabelle

[Manok101]

well slightly elongated is the best description I have. I'll check the next night I take it out to see if they're points in the center.

[IvanT]

I've found that some EPs lead you to think collimation is out and others don't, so don't rely on what a focused EP is telling you, star test it.

Sent from my iPhone using Tapatalk

[callisto]

Have a look at this, hope it helps: Collimation

[beamish]

Research, research, research, then research some more before you even consider going anywhere near your scope with tools . Get it wrong and you'll induce panic and stress and endless worry and postings on threads asking for advice etc, posting pics and the like.

Test against a star first off when skies are reasonably good, choose a mag 2 star and try and get as near focus as possible and check what you see on both sides of focus point with reference images on the net. Make sure the star is centred in your FOV too.

Then decide whether you need to collimate. Lets be honest guys it's pretty daunting the first time you do it

[AndyH]

Lets be honest guys it's pretty daunting the first time you do it

Dread, springs to mind

[Moonshane]

don't worry. it's all adjustable so if you can adjust it wrong you can adjust it right again.

[HippyH]

Here is where I went to learn how to collimate mine.

This guy is good too, tho much more detailed

I was really nervous the first time I did mine. The grub screws were so tight I started to bend the supplied allen key. Collimated it in my kitchen and check it every time I use it. 5 trips out and still spot on.

[beamish]

don't worry. it's all adjustable so if you can adjust it wrong you can adjust it right again.

Just might take a bit longer - ta da !

[Moonshane]

yeah true but the more wrong you make it, the more you learn about collimation! (can you tell I'm an optimist?).

[beamish]

wise & true !

[Moonshane]

not sure about the wise bit