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Here’s Everything I’ve Learned About Laser Collimators Through Years of Handling Several

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Laser collimators are used for aligning the optics of Newtonian reflector telescopes and some catadioptric and Cassegrain telescopes, if need be.

Laser collimators project a beam of light down your telescope tube and allow you to make sure your optics are aligned by getting light to hit the center of your primary mirror and bounce back perfectly into the focuser.

Laser collimator used by me, on a desk
Howie Glatter Laser; one of the best-performance laser collimators that I’ve used. Image: Zane Landers

You want to get a laser collimator if you:

  • Use a reflecting telescope with a focal ratio of f/4.5 or faster
  • Observe a lot at high magnification
  • Have a sturdy, metal focuser
  • Do astrophotography

You don’t want a laser collimator if you:

  • Use a slow f/ratio reflecting telescope (for eg., a f/10 scope)
  • Have a focuser with any play or wobble, such as a plastic rack-and-pinion focuser
  • Use a telescope which doesn’t require frequent collimation

The Good and The Bad That I Noticed

Laser collimators are superior to regular Cheshire collimators and collimation caps. However, laser collimators are not perfect.


Easier to use in the dark if we have set up the telescope after dark.

Very sensitive to misalignment, making them arguably a must-have if you have a telescope with a focal ratio below f/4.5 or so.

Theoretically, it should be able to offer near-perfect alignment accuracy, just as good as collimating on a defocused star at high magnification.

Can be used to collimate Schmidt-Cassegrain, Ritchey-Chretien, and other Cassegrain-type telescopes if you know what you are doing, though I don’t consider it to be the most intuitive or affordable option.


Extremely sensitive to mechanical misalignments in the telescope that may not ultimately matter, such as the screws or compression ring in your focuser de-centering or tilting the laser.

Can be rendered nearly useless if the laser itself is not aligned with the barrel of the collimator. This requires adjustment with the laser sitting in some sort of V-block to correct.

Make us think our secondary mirror is aligned when it’s actually rotated out of alignment and tilted severely. This may be hard to know if we don’t check with a collimation cap or Cheshire first.

Require that we put an accurate center dot on the primary mirror. Without one, they are nearly useless for collimation.

I’d actually recommend you use the laser collimators not on their own but in conjunction with other collimation tools and methods, such as a collimation cap/Cheshire. Before using a laser, I always use such a tool to check for coarse secondary mirror alignment.

Checking the collimation on a defocused star after we use the laser collimator is also always a good idea.

My Experiences With Laser Collimators That I Consider The Finest

I Got the Best Performance From Howie Glatter

The Howie Glatter laser collimator is best-in-class, though the price is higher than that of many premium eyepieces.
Laser collimator used by me, on a desk
Howie Glatter laser collimator from my collection.

The Howie Glatter laser collimator offers superb machining accuracy and a laser that is certain to be dead-on from the factory.

Numerous alternative lenses, upgrades, and accessories are also available for this collimator.

I could use the hybrid 2″/1.25″ version with either size focuser without any difficulties or concerns about decentering the laser with an adapter.

However, before buying a Glatter TuBlug, which cost as much as the collimator itself, I had to look into the focuser to check my primary mirror alignment and then go back down to the adjustment screws instead of being able to check the alignment in real time. This was a bit of a pain initially.

The TuBlug, if you buy it, can also amplify the sensitivity of your laser to miscollimation. However, it may induce mechanical misalignment/sagging if your focuser cannot handle it.

$310 at Agena Astro

A Cheaper “Howie Glatter” That I’ve Used: Farpoint

The Farpoint laser collimator is suitable for all but the most demanding users and fastest telescopes, with a similar design to my favorite Howie Glatter laser.
Farpoint laser collimator kept in my table.
Farpoint laser collimator that I’ve used and tested. Image: Zane Landers

The Farpoint laser collimator is one great collimator that I noticed to be very similar to the Glatter in basic design and advantages.

It comes in a 1.25”/2” hybrid barrel for use in any size focuser without the need for an adapter, just like the Howie Glatter.

However, compared to the Glatter, it is a little harder to see very small amounts of misalignment, and the family of accessories and other products is not as diverse as what is offered for the Glatter.

The Hotech SCA laser is a favorite of many users; however, the SCA rubber adapters aren’t for everyone and can be problematic to use in some telescopes.
Hotech SCA collimator from my astronomy collection. Image: Zane Landers

The Hotech SCA laser collimator fits in either a 1.25” or 2” focuser using its proprietary “self-centering” rubber adapters.

It also has a built-in 45-degree window, so I could use it even while adjusting screws at the other end of the telescope.

However, I sometimes had issues due to the SCA rubber adapters with some telescopes, especially very fast instruments.

For Those In a Budget, I’d Recommend Apertura Laser Collimator

The Apertura laser collimator is fairly easy to use and affordable, but often ships with alignment issues that must be fixed before the laser can be used.

The Apertura laser collimator uses a 45-degree window like the Hotech SCA laser, though we’ll need to provide our own 1.25” to 2” adapter.

This is the same laser that is thrown in with the Apertura AD Dobsonians.

One thing I’ve noticed is that it’s a lot less accurate than more expensive lasers due to the lack of a precision 2” adapter, grid lines, and machining tolerances.

There’s also a pretty good chance the laser will arrive misaligned with the collimator barrel from the factory, making it useless until we adjust it in a V-block with the (thankfully exposed) hex key screws.

The Cheapest Recommendable Laser Collimator That I’ve Had My Hands On: SVBony

The SVBONY laser collimator suffers from similar quality control issues to the Apertura in that the lasers rarely arrive aligned with the barrel and I had to fix it before usage.

The SVBONY laser collimator is similar to the Apertura laser in design and lack of precision, as I’ve used and confirmed. But it’s cheaper and does include a tight-fitting 1.25” to 2” adapter by default.

Like the Apertura laser, many of these lasers ship misaligned with the barrel, requiring us to adjust the alignment in a V-block.

However, the SVBONY laser’s screws are hidden behind rubbery coverings, which I just poked through and destroyed to access the adjustment screws with a hex key.

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Zane Landers

An amateur astronomer and telescope maker from Connecticut who has been featured on TIME magazineNational GeographicLa Vanguardia, and Clarin, The Guardian, The Arizona Daily Star, and Astronomy Technology Today and had won the Stellafane 1st and 3rd place Junior Awards in the 2018 Convention. Zane has owned over 425 telescopes, of which around 400 he has actually gotten to take out under the stars. These range from the stuff we review on TelescopicWatch to homemade or antique telescopes; the oldest he has owned or worked on so far was an Emil Busch refractor made shortly before the outbreak of World War I. Many of these are telescopes that he repaired or built.

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