Another newbie Collimation question.

[SmokeyJoe]

Quick one, had my sw 200 for a couple of years, it worked fine out of the box, did not need collimating, I have not used it for three years during which time it has been stored in the original box. I figure it will need collimating as I have moved house and it has been moved from room to room a few times. but is there anyway I can check without looking at a star. With the weather at the moment it seems like a good idea to do some maintenance before getting back to the hobby.

[JG777]

Yes if you have the necessary tools, and worth doing before you go out. If it was ok before then it's likely the secondary mirror will not have moved so it's probably just a tweak on the primary mirror. I use a collimation cap for the secondary and a Cheshire for the primary. Plenty of guides about on the net and many swear by Astro baby's guide. 

[laudropb]

You might get a pleasant surprise and find that the primary only needs a slight tweak, but as has been mentioned above you will require a collimating tool such as a Cheshire.

[davyludo]

1 hour ago, JG777 said:

Yes if you have the necessary tools, and worth doing before you go out. If it was ok before then it's likely the secondary mirror will not have moved so it's probably just a tweak on the primary mirror. I use a collimation cap for the secondary and a Cheshire for the primary. Plenty of guides about on the net and many swear by Astro baby's guide. 

Hi John, 

Sorry for the silly question - but can you use the Cheshire to align the secondary as well? If so, is there a reason that a collimation cap is better/easier for secondary alignment? 

Cheers, 

Davy

[JG777]

14 minutes ago, davyludo said:

Hi John, 

Sorry for the silly question - but can you use the Cheshire to align the secondary as well? If so, is there a reason that a collimation cap is better/easier for secondary alignment? 

Cheers, 

Davy

No silly questions here, we all start somewhere. I find the collimation cap for secondary shows a wider view to the edge without crosshairs, also if you insert cardboard or paper behind the secondary it does away with the confusing reflections. Then you can see the whole of the secondary mirror without any interference through the cap to centre it perfectly. You probably can use a Cheshire but I found it does not give a great view for the secondary. Most guides advocate a cap for the secondary and a Cheshire for the primary. 

[davyludo]

6 minutes ago, JG777 said:

No silly questions here, we all start somewhere. I find the collimation cap for secondary shows a wider view to the edge without crosshairs, also if you insert cardboard or paper behind the secondary it does away with the confusing reflections. Then you can see the whole of the secondary mirror without any interference through the cap to centre it perfectly. You probably can use a Cheshire but I found it does not give a great view for the secondary. Most guides advocate a cap for the secondary and a Cheshire for the primary. 

Thanks for that John - makes sense to me now. Thought I was being clever just buying a Cheshire..."It's just something with a wee hole in the top, surely I can use it instead of a collimation cap?!" Just trying to cut corners 

More toys to buy!

[davyludo]

Dom - for what it's worth, I usually collimate mine with a Cheshire during the day when it's light . Then when I take it out at night I do a quick star test. 

Whether or not this is a good way to do it, I don't know...but it works for me (I've not tried collimating outside at night yet).

Photons hit my eyeballs and I see shiny things, so I'm happy 

[rockystar]

I don't have any issues using a Cheshire for the secondary - as mentioned, It's just a bit of a narrower view (so I'm led to believe).

[JG777]

A Cap is just a few pounds so not a bank buster! But as you can see plenty are getting by with just a Cheshire ?

[SmokeyJoe]

Thank you all once again for the advice.  My new eq5 goto has just arrived so I'm going to open up the box, let the clouds out in the hope that they will blow away in the storm and have a go at Collimation today or tomorrow, depending how long it takes me to read manuals etc.