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A reflector out of true performs like a smaller telescope

The best collimators for 2026

Collimation is the act of aiming the two mirrors of a reflector at each other, and a tube that has travelled in a car boot will need it. A telescope that is out of true does not look broken — it looks like a telescope of smaller aperture, showing soft detail and a bloated star image, which is why the fault so often goes undiagnosed and the instrument gets blamed. A collimator is the tool that makes the adjustment a five-minute routine instead of guesswork. The shelf divides by method. A laser collimator projects a beam down the tube and shows where it lands; it is fast, it works alone in the dark, and it depends on one thing that many of them get wrong — the laser must be aimed exactly along the axis of its own barrel, and a tool that is not itself collimated confidently aims the telescope wrong. Look for one that can be self-collimated, with adjustment screws in its own body, and test it by rotating it in a V-block. A Cheshire eyepiece or sight tube uses no electronics, cannot drift, and asks for daylight or a torch; many experienced observers keep one to check the laser. The other cause of error is barrel play: any slop between the tool and the focuser translates directly into a misaimed beam, and a compression ring in the focuser is part of the solution. Read the brightness control if the target is bright enough to dazzle. We compare method, self-collimation ability, barrel fit and play, brightness control, target visibility, build and suitable telescopes.

The parts here, column by column

  1. Bresser laser collimator in black anodised aluminium

    Bresser Newtonian laser collimator (4910200)

    A 1.25 in laser collimator in an adjustable aluminium housing, with a roughened surface for reading the return beam, published at 212 g.

    Method
    Laser collimator
    Self-collimation ability
    Adjustable anodised aluminium
    Barrel fit
    31.7 mm (1.25 in)
    Play
    Not published by the maker.
    Brightness control
    Not published by the maker.
    Target visibility
    Roughened, so the reflected spot can be seen
    Build
    212 g, as the maker publishes it · Not mentioned in the listing
    Suitable telescopes
    Newtonian, Schmidt-Newtonian and Maksutov-Newtonian, as the maker lists them
    Amazon reference
    B00ADENLT0 (same reference on 5 Amazon marketplaces)
    EAN
    4007922002767
    • An adjustable housing means the tool itself can be trued, which is the precondition for trusting it
    • The three suitable telescope types are named rather than left as “reflectors”
    • No wavelength or output power figure is published

    Best for: Collimating a Newtonian in the dark without a second person or a second tool

    ≈ £75 / €75
    Check price on Amazon
  2. Astromania 1.25 inch laser collimator in anodised aluminium

    Astromania Next-generation 1.25 in laser collimator (ZAA1025)

    A metal-bodied laser collimator with seven brightness steps, a published wavelength band and output figure, and three sealed adjustment ports for trueing the tool itself.

    Method
    Laser collimator
    Self-collimation ability
    Three ports at 120°, initially sealed behind a screw cap at the rear
    Barrel fit
    Standard 1.25 in
    Play
    Not published by the maker.
    Brightness control
    635–655 nm, as the maker publishes it · Less than 5 mW, as the maker states it · Seven
    Target visibility
    Not published by the maker.
    Build
    CR2032 lithium; the maker states it is not supplied
    Suitable telescopes
    Not published by the maker.
    Amazon reference
    B01D8HMBCQ (same reference on 5 Amazon marketplaces)
    EAN
    6970019295022
    • Wavelength and output power are both published, which is rare on this shelf
    • Three adjustment ports at 120° let the tool be trued rather than trusted
    • The battery is not supplied and CR2032 cells are easy to be without on the night

    Best for: A Newtonian owner who wants a laser they can check and correct themselves

    ≈ $26 / £32
    Check price on Amazon
  3. Seben LK1 laser collimator with metal housing

    Seben LK1 laser collimator

    A 1.25 in laser collimator in a metal housing for aligning Newtonian reflectors, with no wavelength, power or adjustment detail published.

    Method
    Laser collimator
    Self-collimation ability
    Metal · Not mentioned
    Barrel fit
    31.7 mm (1.25 in)
    Play
    Not published by the maker.
    Brightness control
    Neither is published
    Target visibility
    Not published by the maker.
    Build
    Not mentioned
    Suitable telescopes
    Newtonian reflectors, per the maker
    Amazon reference
    B006FGYWM0 (same reference on 5 Amazon marketplaces)
    EAN
    4250403200408
    • A metal housing rather than plastic at a low price
    • The one job it is for is stated clearly
    • No wavelength, no output power and no battery type

    Best for: A first collimator where price decides and the tool will be checked on arrival

    ≈ £26 / €29
    Check price on Amazon
  4. SVBONY collimator with 2 inch adapter

    SVBONY Collimating eyepiece with 2 in adapter (EUF9123A)

    A metal collimator supplied with a 2 in adapter so it fits both focuser sizes, with a triplet lens and seven brightness settings.

    Method
    Triplet lens, described by the maker as reducing distortion and spherical aberration
    Self-collimation ability
    Not mentioned
    Barrel fit
    1.25 in, with a 2 in adapter supplied
    Play
    Not published by the maker.
    Brightness control
    Seven, from 0 to 7 per the maker · Neither is published
    Target visibility
    Not published by the maker.
    Build
    Metal
    Suitable telescopes
    Newtonian and Schmidt-Cassegrain reflectors, 1.25 in and 2 in
    Amazon reference
    B013SMDQSY (same reference on 5 Amazon marketplaces)
    EAN
    0635266493268
    • The 2 in adapter is supplied rather than sold separately
    • A triplet lens is specified, which is unusual detail for a collimator
    • No wavelength or output figure

    Best for: An observer with both a 1.25 in and a 2 in focuser who wants one collimator for both

    ≈ £35 / €36
    Check price on Amazon
  5. POFET metal collimator with 2 inch adapter

    POFET Metal collimating eyepiece with 2 in adapter

    A metal collimator with a triple-cemented lens and a built-in battery offering seven brightness levels, supplied with a 2 in adapter.

    Method
    Triple-cemented lens, per the maker
    Self-collimation ability
    Not published by the maker.
    Barrel fit
    1.25 in, with a 2 in adapter
    Play
    Not published by the maker.
    Brightness control
    Seven · Neither is published
    Target visibility
    Not published by the maker.
    Build
    Built-in battery, described as power-saving
    Suitable telescopes
    Newtonian, per the maker
    Amazon reference
    B08M9FRYXP (same reference on 5 Amazon marketplaces)
    EAN
    0703355530023
    • The maker describes the actual procedure rather than only the product
    • A built-in battery removes the CR2032 problem on a cold night
    • A built-in battery cannot be replaced when it eventually fails

    Best for: A Newtonian owner who would rather charge a tool than keep spare cells

    ≈ £23 / €26
    Check price on Amazon
  6. Jadeshay collimating eyepiece with red crosshair

    Jadeshay Collimating eyepiece with crosshair

    An aluminium collimating eyepiece with a red crosshair and a long tube, working without any power source at all.

    Method
    Optical collimating eyepiece — not a laser, and it needs no battery
    Self-collimation ability
    Not published by the maker.
    Barrel fit
    1.25 in
    Play
    Not published by the maker.
    Brightness control
    Not published by the maker.
    Target visibility
    Red crosshair · Described by the maker as unusually long for better accuracy · Treated to reduce reflections, per the maker
    Build
    Aluminium alloy
    Suitable telescopes
    Newtonian, per the maker
    Amazon reference
    B07KBXNRNH (same reference on 5 Amazon marketplaces)
    EAN
    0788051500754
    • No battery to go flat, which is the failure mode of every laser on this shelf
    • A long tube genuinely improves the accuracy of a sighting collimator
    • It needs enough light to see the reticle, which means a torch in the dark

    Best for: Anyone who would rather have a tool with nothing in it to fail

    ≈ £21 / €23
    Check price on Amazon

Any figure written into the body of this page was true on the day it was written. The amount shown next to each instrument is requested from the retailer as the page loads, and it is that amount, not the text, that stands.