Coma Corrector 0.95x (ART-COMACORR)


Coma Corrector 0.95x (ART-COMACORR)

Regular price
$ 289.00
Sale price
$ 289.00
Unit price

This item is out of stock but you can place an order now and we’ll ship when it becomes available.


  • 2 "coma corrector with 0.95x reduction factor
  • Compatible with Newtonians from f/4.0 to f/6.0
  • Completely corrected up to APS-H format


The coma corrector is a very important accessory for all Newtonian telescopes with a focal ratio from f/6.0 to f/4.0; it allows to correct the field also with cameras equipped with large sensors, up to APS-H format

It fits into the 50.8mm connection of your focuser like a normal 2" eyepiece and has an M48 x0.75 thread on the camera side for connecting Reflex, CCD or CMOS cameras.

On the internal side (telescope side) there is a thread to connect 2 "filters (50.8mm), such as a narrow band filter or a filter for light pollution.

It will thus be possible to reduce the focal length of your Newtons, for example a Newton with native focal f/4.0 will be reduced to a resulting focal equal to f/3.8.


This coma corrector has been specifically tested with the Newtons of the following brands to test its compatibility, for any information about it, please contact us:

Artesky Newton Artec 200 Lite Yes
Skywatcher Newton PDS series Yes
Newton QUATTRO-S series Yes
GSO Newton F / 5.0 and F / 4.0 Yes
TS Optics Newton F / 5.0 and F / 4.0 Yes
Celestron Newton F / 5.0 Yes

What is coma?

Coma is an optical aberration that derives its name from the classic comet-like appearance of the images created by the optical systems that assume this defect.

Coma occurs when the imaged object is moved laterally with respect to the system axis by a certain angle. The rays passing in the periphery to the optical axis are focused in a different point of the axis, further away if the coma is positive or closer if the coma is negative.

A bundle of rays passing through the lens at a certain distance from the center are focused in a ring shape on the focal plane, the superposition of these different rings gives rise to a V-shape similar to the tail of a comet.

As with spherical aberration, coma can also be reduced or eliminated by using appropriate coma correctors for the optical system concerned.





Technical features

Compatible with Newtonian telescopes from 150mm to 300mm aperture, focal ratio between f/4.0 and f/6.0

Magnification factor: 0.95x

Correct field: APS-H

Optical elements: 3 optical elements with multi-surface treatment

Outer diameter: 2 "(50.8mm)

Backfocus: 55mm

Total corrector length: 79.74mm

Weight: 0.35kg

Spot diagram

The spot diagram below shows the tests carried out for a Newton with native focal f/4.0

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