Premium Cheshire Collimator vs Baader Laser Collimator?

[Guest]

A few weeks ago, I bought a Premium Cheshire Collimator from Auntie FLO.  Initially, I struggled with it and I found help through the forum.👍 The main problem was getting the secondary mirror rotated correctly to face the focuser.  After this, it seemed to be okay and I proceeded on to do the primary mirror, etc.

A few days after this, I attended the New Galloway Star Camp down at Drumroamin.  Somebody suggested that I tried their Baader Laser Collimator (the mk3, I think).  He adjusted my primary just a tad, as it wasn't too far out.  Upon asking, he said that his Baader was already collimated.  Given the price and the reviews I've read recently, I've no reason to doubt this kind gentleman.👍  After all, he helped me out in many ways, the few nights that I was there.

My questions are, is Cheshire collimation quite hard to get the secondary aligned to the focuser?  Would the Baader definitely be better for me, as it's quicker?  Is the Baader more accurate or about the same as the Cheshire method? 

I've used the Astrobaby method of Cheshire collimation, but have found it's quite daunting for the absolute beginner!

[johninderby]

Best tool bar none for correctly centering the secondary is a Concenter.

Available from Telescope Express or APM

Edited October 29, 2020 by johninderby

[popeye85]

Agree with the above. I've only just revieced mine but it definitely gives you a much more precise method of getting the secondary correct! Although you will probably find your self pulling your hair out!! I have also seen someone using a converted webcam to get the desired results.

With regards to a laser Vs Cheshire. I have always used a Cheshire as you know it will always be correct whereas some lasers can lose their collimation. (can't speak about the baader as I've never used one) however for checking collimation in the dark then a laser is the best for the job.

I agree that it can be a daunting task but it's one of these things that is best just to grab the bull by the horns and get on with it!!!!

[Ricochet]

5 hours ago, merlin100 said:

Would the Baader definitely be better for me, as it's quicker?  Is the Baader more accurate or about the same as the Cheshire method?

No. You can't centre the secondary under the focuser with a laser, you have to start with some sort of sight tube, be that a combined cheshire/sight tube or concenter as suggested above. The laser can then be used to align the secondary to the primary, but the problem with the Baader is that it doesn't have an angled face to allow you to watch the collimation change from the primary end of the telescope when you collimate the primary. 

[Guest]

25 minutes ago, Ricochet said:

No. You can't centre the secondary under the focuser with a laser, you have to start with some sort of sight tube, be that a combined cheshire/sight tube or concenter as suggested above. The laser can then be used to align the secondary to the primary, but the problem with the Baader is that it doesn't have an angled face to allow you to watch the collimation change from the primary end of the telescope when you collimate the primary. 

Thanks, that's saved me paying out for something that I don't need.  Does this mean that my Premium Cheshire from FLO is everything that I need?🤔

[Ricochet]

4 minutes ago, merlin100 said:

Thanks, that's saved me paying out for something that I don't need.  Does this mean that my Premium Cheshire from FLO is everything that I need?🤔

Not quite. I use a a premium Cheshire for my secondary and switch to a short Cheshire with the crosshair a removed for the primary. I used to use a barlowed laser for the primary, but the batteries ran out and I still haven't got round to replacing them. 

This is the style of short Cheshire I have https://www.ebay.co.uk/itm/293772110824. You might find sellers with even cheaper prices, that was just the first search result. 

[Dark Vader]

I bought a collimation cap for the secondary and a premium Cheshire for the primary.

For checking collimation in the dark I just shine the red torch at the reflective surface of the cheshire. 

[John]

3 minutes ago, Ricochet said:

Not quite. I use a a premium Cheshire for my secondary and switch to a short Cheshire with the crosshair a removed for the primary. I used to use a barlowed laser for the primary, but the batteries ran out and I still haven't got round to replacing them. 

This is the style of short Cheshire I have https://www.ebay.co.uk/itm/293772110824. You might find sellers with even cheaper prices, that was just the first search result. 

Thats how I do it as well. I do have a laser collimator and it is collimated but I use that more often for checking the alignment of refractor focusers.

My secondary rarely moves so most of the time it's a quick check with the short cheshire, tweak if needed and on we go.

 

[Guest]

I think I'll sleep on this, as it's a lot to get my head around...

[Guest]

10 hours ago, Ricochet said:

Not quite. I use a a premium Cheshire for my secondary and switch to a short Cheshire with the crosshair a removed for the primary. I used to use a barlowed laser for the primary, but the batteries ran out and I still haven't got round to replacing them. 

This is the style of short Cheshire I have https://www.ebay.co.uk/itm/293772110824. You might find sellers with even cheaper prices, that was just the first search result. 

I sometimes have difficulty in seeing the reflection of the 3 primary mirror clips, even though the secondary looks well aligned. I've tried raising and lowering the Premium Cheshire in the focuser tube and also raising and lowering the focuser tube. 

Would a shorter Cheshire help me in this regards? 🤔

[Geoff Barnes]

7 minutes ago, merlin100 said:

I sometimes have difficulty in seeing the reflection of the 3 primary mirror clips, even though the secondary looks well aligned. I've tried raising and lowering the Premium Cheshire in the focuser tube and also raising and lowering the focuser tube. 

Would a shorter Cheshire help me in this regards?

My experiences echo yours merlin100, I have both long and short Cheshires and find that the secondary clips are only clearly visible through the short, and no matter how I move the long in or out it never shows them more than the tiniest glimpse at the very edge of view. This is in my 12 inch Dob.  

[Ricochet]

1 hour ago, merlin100 said:

I sometimes have difficulty in seeing the reflection of the 3 primary mirror clips, even though the secondary looks well aligned. I've tried raising and lowering the Premium Cheshire in the focuser tube and also raising and lowering the focuser tube. 

Would a shorter Cheshire help me in this regards? 🤔

It might, but then you might have the opposite problem that the edge is too far away. Remember with the premium cheshire you don't have to insert it all the way into the focuser so you can gain a couple of inches of travel that way too if needed. 

[Neil H]

Hi if you want a baader lazer collimater there is one for sale on astro buy and sell

https://www.astrobuysell.com/uk/propview.php?view=167452

Edited October 30, 2020 by Neil H

[Matt61]

I'm a total novice who was daunted by collimation. However got the same Cheshire and on a 150P Newtonian it was pretty easy. I agree seeing mirror clips is tricky but I found that concentrating on a circular secondary more productive. ( mirror tilt and rotation being critical) pleased to say star test was spot on .

However I have laser as well and it's not accurate ( I've given up trying to collimate it ) I trust my eyes and Cheshire more.

[popeye85]

I never bother about seeing the clips. Get secondary aligned with the focuser is the priority. Then just aim up the center spot.

[Guest]

As can be seen from this earlier thread, you can see the difficulties I was having... 

 

[Guest]

2 hours ago, popeye85 said:

I never bother about seeing the clips. Get secondary aligned with the focuser is the priority. Then just aim up the center spot.

I suppose the other thing is that you can become fixated looking for perfect collimation and forget to actually look at the stars! 😯

[Pixies]

The whole point of a Cheshire is that you don't need to see the primary clips. That's only when you are using a collimation cap.

With the Cheshire, once you have used it as a sight-tube to position the secondary under the focuser, you then adjust the secondary tilt so that the doughnut is directly under the crosshairs. Having the doughnut and crosshairs aligned means the primary is centred in the secondary. You don't need to worry about the primary mirror clips.

Edited October 30, 2020 by Pixies

[Guest]

15 minutes ago, Pixies said:

The whole point of a Cheshire is that you don't need to see the primary clips. That's only when you are using a collimation cap.

With the Cheshire, once you have used it as a sight-tube to position the secondary under the focuser, you then adjust the secondary tilt so that the doughnut is directly under the crosshairs. Having the doughnut and crosshairs aligned means the primary is centred in the secondary. You don't need to worry about the primary mirror clips.

Thanks once again...  I find the various methods quite confusing.