Apertura

Apertura Laser Collimator

1.25" · with 45° window

Aligns the mirrors in a Newtonian or Dob in under a minute, so every star snaps to a tight point instead of a soft blur.

84/ 100

Polaris Score

#2 of 7 collimation tools we recommend

From$59.95

Where to buy

High Point ScientificBest price$59.95→

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What problem does this solve?

A Newtonian out of collimation throws away half its aperture.

Every reflector’s mirrors drift out of alignment as it is carried, cooled and bumped. Even a small misalignment smears the light cone, stars bloat, planets lose their fine detail, and the scope never shows what its aperture promises.

A laser collimator drops into the focuser and projects a beam down the optical axis. You adjust the mirrors until the returning dot lands dead-centre on the target, a fast, repeatable, daylight-or-dark way to get the optics perfectly aligned before you observe.

You need one if

You need one if you own a Newtonian or Dobsonian, they need collimation regularly, and a laser makes it a one-minute habit instead of a chore.

You can skip it if

You can skip it for refractors, SCTs and Maks, which hold collimation far longer and rarely need user adjustment.

01Will it fit my setup

Compatibility.

What this accessory works with — check the fit before you check the price.

NewtonianDobsonian1.25" focuser2" via adapterFast & slow mirrors

Note✕Not for refractors✕Needs its own collimation check

02The numbers

What These Numbers Mean

What it doesMaintenance

Aligns Newtonian mirrors

It projects a beam down the tube so you can see exactly where the optical axis falls, and adjust the secondary and primary until the beam returns on itself. A misaligned reflector shows soft, flared stars that no eyepiece upgrade will fix.

Barrel sizeStandard

1.25 inch

Drops into any standard focuser, including 2 inch focusers with the usual adapter. Focuser slop matters here: a loose fit lets the collimator tilt and gives you a false reading.

How oftenDepends on f-ratio

Fast scopes, every session

At f/4 to f/5 collimation drifts enough to matter after transport, so a two-minute check before observing is normal. At f/8 a reflector can hold alignment for months.

The catchVerify

It must be collimated itself

A laser whose own beam is off-axis will confidently align your telescope incorrectly. Roll it in a V block and check the dot does not circle before trusting it, or cross-check against a Cheshire eyepiece.

Optical

TypeCollimation laser

Wavelength650 nm (red)

Fit1.25" barrel

45° windowYes, read from the side

ClassClass 2 / 3R

Physical

BodyMachined aluminium

PowerButton cells

Grub screwsFor self-alignment

Weight~90 g

03Before you buy

Good to know.

The honest caveats — the things that save you a return, a bad first night, or a second purchase you didn't need.

Collimate the collimator first.

A laser that is itself out of true will send you chasing your tail. Roll it in a V-block and adjust its grub screws until the dot does not wander.

Do a star test to confirm.

The laser gets you very close; a quick defocused-star check on a real night confirms the last fraction. They agree when both are done right.

Never look into the beam.

It is a laser, treat it like one. Aim it down the tube, not across the field where someone could catch it in the eye.

04Completes the kit

Related accessories.

The no-battery check

Cheshire eyepiece

A sighting tube that cross-checks the laser with zero electronics.

The free starting point

Collimation cap

A capped 1.25" blank for a rough visual alignment first.

Tool-free tweaks

Bob’s Knobs

Thumbscrews that replace mirror-cell Allen bolts for hand adjustment.

84/ 100

Apertura Laser Collimator

1.25" · with 45° window · $59.95

Aligns the mirrors in a Newtonian or Dob in under a minute, so every star snaps to a tight point instead of a soft blur.

High Point ScientificBest price$59.95→