Which are the better laser collimators?

[mental4astro]

I'm not sure which forum to slip this one in: this one or the 'Eyepiece' forum?!

I've got a GSO laser collimator, so dose a mate of mine. Both of us have the same problem- the collimator has a sloppy fit in the 1.25" focuser, with both types of fixing styles, screw or compression ring. Therefore I have no confidence in the quality of the resulting collimation effort, as the collimator is not held securely in the focuser- there is a wobble when the holding screw is tightened. Shows up in the image quality as the stars are still not pin-point (secondary alignment is good).

So, my question is who has a brand of laser collimator they are willing to recommend? This problem undoes the work that's gone into rebuilding my 17.5" dobbie, :(. My focuser is a 2" type with a 1.25" adaptor. Is there an addvantage of using a 2" collimator over a 1.25"? The newtonians I have all have 2" focusers.

Mental.

[mithrandir]

Howie Glatter do a 1.25/2" but will only be as repeatable as the screw locking in your focuser tube lets it be. Bintel stock them.

Hotech are designed to be self centering, but from their web site only seem to be made for Cassegrain based designs. MyAstroShop stock Hotech.

[jakob]

I had a problem with the 1.25 versions in my LB16.
The adaptor adds another inaccuracy to the alignement and the barrel is to short.
I now have a 2" from Bintel. I feel its is doing a good job. There is a threaded mask for the laser beam that can be changed to a barlow attachement.

I'm very happy with it.

It's not as cnvienient as the Orion Laser collimator (you can observe the dot white adjusting) but the result differed each time you moved the collimator.
https://www.bintelshop.com.au/Images/Stock/8428.jpg

[Barrykgerdes]

A laser collimator is a great tool for setting up the collimation but I would doubt if most of commecial ones would be very accurate out of the box because of the difficulty of making a "fits all" adaptor.

Their accuracy depends on the path of the beam being truly orthogonal. To achieve this you must first get rid of any slop in the fit then rotate the collimator through 360 degrees and ensure the spot does not move.

This procedure needs patient "Preliminary" collimating till the spot is in fact being returned near enough to its source to actually check it.

Part of the initial collimation set up is to check the centering, reflection (shadow) of the diagonal mirror on the main mirror. For this to be useful you must have the secondary holder properly centered also.

Pay attention to these basics first and then just about any laser collimator will give good results.

Barry

[mental4astro]

Good point, Barry. Thanks.

I have marked the off-set centre of my secondary. Making sure the laser is aligned to it is something I'll keep an eye on.

The slop in the focuser is something else I'll look at.

A 2" collimator then serves to reduce the error introduced by a 1.25" adaptor.

Thanks gentlemen.

[erick]

Hotech works fine in newtonians - unless they have dropped that model from their lineup?

Wrap the barrel of the GSO with a turn of "contact". In my experience, that produces a snug fit in GSO focussers (actually in the 2"-->1.25" adapter).

[JethroB76]

Howie Glatter, Astrosystems are two. Both very good imo

[wavelandscott]

Cat's Eye and Howie Glatter rank at the top of the list in my opinion...

[TheAstroGuy]

Howie Glatter with the Tublug fitting is absolutely the simplest and best around i reckon. Cat's eye also good but for ease of use and accuracy and the ability to collimate on your own Howie glatter is Definately the way to go without a doubt, i have a two inch barlowed Howie glatter and tublug and my 12'' reflector has incredibly accurate collimation so quickly and simply.
Regards

Shane

[Kevnool]

Howie Glatter seems like the go with most of us.
You pay more but you pay for quality.
Cheers Kev.

[Sentinel]

I agree.

Start with a Catseye System. I have a Glatter collimator and it's great but the Catseye system is better bang for the buck.

[Omaroo]

Another very firm vote for the AstroSystems barlowed collimator. SDM sell them here in Oz, and I have nothing but praise for mine. Others I've performed on-field collimation services for have also been highly impressed with its accuracy and ease of use. In the same league as the HG and CatsEye, without doubt. AstroSystems state that if it is ever out of collimation itself, you send it back to the USA for them to re-collimate at their expense. It's something I've never heard of anyone actually having to do - so that's proof enough of how stable they are.

[gb_astro]

Just to mix it up a bit, the 2" AstroSystems laser fits nicely in the 2" Howie Glatter Tublug.

gb.

[NeilW]

From what I can see on their website, the AstroSystems laser only comes in a 2" model, is that correct?

[robz]

Howie Glatter!....................a freind just collimated my newtonian and I was very impressed with it's build quality and tight fit/tolerances:thumbsup:

[Krumlov]

Hi Guys,

Just looking for some updates on collimators. I am planning to buy a 8" GS-680 soon. My extensive reading suggests a collimator is mandatory although the scope doesn't come with one as standard which would suggest to me that you can get by without one?

Despite this conundrum I have looked at the options and I have the following spanning the range of prices:
1.25" Guan Sheng deluxe Newtonian laser collimator...A$59
2" Howie Glatter and Tublug direct from them in the USA...~A$260
HoTech 2" & 1.25" SCA Crosshair Laser Collimator ebay...~A$145
2" Astrosystems Barlowed Laser direct from them in the USA...~A$140

I looked at Catseye but the website is atrocious and I could not work out what I needed!

I am pretty sure the Howie Glatter and Astrosystems are Barlowed collimators but I'm not sure about the other two.

Anyway I am not sure that I can justify the Howie Glatter. I am leaning at the moment to the HoTech although I may be overly emphasising their "self centering attachment".

Any comments on the above? So far in this thread people have made recommendations but no-one said why so a bit more info would be great so that I know what exactly are the pros and cons and whether additional expense is justified. I am the type of person who likes to only buy once but if a cheaper model does the job just as well then I would prefer to save the money.

[astronut]

I know the "good" laser collimators work very well.
My vote is for The "Catseye" system.....simply brilliant!!

[catseyeman]

No doubt, there IS a lot of information on the site to mull over and comprehend, but passive tool collimation is not complex. If you need some help in sorting it all out for your needs, drop me a PM or better yet, an email to:

flyj@catseyecollimation.com

Regards,

Jim Fly
CATSEYE Collimation

[gb_astro]

Gavin, yes just a sad fact of life, newtonians need collimators.

What you are paying for is the quality and accuracy of construction.
That is how tightly they fit the focuser draw tube, how they handle the knocks of use,
how accurately the laser axis is aligned with the physical axis etc,.

I own the 2" Howie Glatter and Tublug and used to own
the 2" Astrosystems Barlowed Laser.
Both do the job well.

Glatter stuff is built like a tank and should last a life time.
The Glatter Tublug (barlow lens) allows you to see the returning laser beam from outside your scope when collimating the primary which I find a big advantage. You can crouch down behind the primary mirror and see the laser beam move as you adjust the mirror bolts.

When adjusting the primary the Astrosystems laser uses a barlow lens that is attached to the end of the unit.
With a solid tube scope like the GS-680 you will have to look into the top of the scope to see the returning beam. So it's an adjust-look-adjust-look process unless you have someone to help you.

The problem with the Ho-Tech is that it does not have a barlow attachment to do the primary alignment.
It just uses the return laser beam to hit that external 45° target.
This is generally considered not accurate enough for a fast (f) newtonian scope alignment.

As I mentioned in a post above the Astrosystems laser will fit the Glatter TuBlug so you could start with that and see how you go. You can always get the TuBlug latter.

I also own most of the CatsEye stuff which is all excellent.
Their XLK autocollimator is probably the ultimate collimation device.
However for starters I would have to recommend a laser.

gb.

[norm]

Hi Gavin,

I'm with Greg here :). Go the Astrosystem or the Howie Glatter.

I've got the 2" Astrosystem barlowed Laser collimator and it works a treat. Its also well built.

As Greg mentioned, when collimating the primary you need to tweak the primary knob, stand up and look back in the focuser and do this a number of times. It can be a slight pain the backside and much easier if someone is around to help.

I've put up with this for a year or 2, but I've just ordered the 2" tublug from Howie Glatter (around $126AU posted) and hopefully it will be arriving soon. It's compatible with the AS, so when it does arrive goodbye to having to crouch, tweak primary knobs stand up and go back to the top to check the focuser etc (and repeat 4-5 times). It can be all done crouching down at the rear of the scope and done in less than a minute.

End of the day, imo, buy quality and you won't regret it.

Cheers,
Norm

[qld]

hi team ,
Obsession recommends the astorsystem , i have tried many types of laser collimators and for my two obsessions i have found the 2inch Astrosystem excellent, its quick and easy to use and if you want perfection then in addition use the Astrosystem autocollimator its simple to use also .Both are intuitive and you dont need a degree in collimation.The kiss principle is allways best imo

[Krumlov]

Thanks John, Jim, Greg and Norm.

Firstly let me say to others reading this in the future that I did finally find the information I needed on the Catseye system. You need to scroll right to the bottom of the left hand frame and there is an "Information Links" section that should have everything you need.

So I appear to be down to Howie Glatter, Astrosystems and Catseye.

Greg could you expand a little on why you would recommend a laser first? If the Catseye system provides the best alignment then why not just go for it. Or are you suggesting that to a novice the additional accuracy would not be discernable and thus I would be better putting the $100 difference into something else?

Cheers!

[solissydney]

Why don't you just make up a cardboard sleeve on the collimator?
Ken

[gb_astro]

The CatsEye crosshair and cheshire tools will get you as
close to excellent collimation as a good laser will.
However I just find the laser easier to use.

The CatsEye autocollimator is a final tweaking tool.
You need to be pretty well spot on with your collimation before you can
use it easily. So you need the other CatsEye tools, or a laser, as well.

Also apparently the slower your scope the less benefit there is to be gained from the autocollimator.
The CatsEye website seems to imply that about f6 is the cut off point.
The GS-680 is f6 so I can not see the autocollimator justified, at least as an initial investment.

gb.

[Hagar]

In most cases a laser collimator is that but to use any effectively you must collimate the laser first.

The other thing I would look for is a laser with a fitted lens to set the laser to just a focused dot rather than the various paterns which come out of the cheap ones without a lens.

Of the cheap range the best I have found was the Orion deluxe laser collimator. At $149 for a lensed unit which doesn't use the el cheapo laser pointers from the junk shops as it light source but rather a true commercial laser module.

[Krumlov]

OK sounds great. Unless someone comes up with some alternative points of view I will go for the Astrosystems.

Thanks for all the help guys.