Newtonian reflector collimating tool

Celestron Newtonian reflector collimating tool

6 Review(s) | Add Your Review

$39.95

Availability: In stock

The Celestron Newtonian reflector collimating tool is a combination of a sight tube and a Cheshire eyepiece in a single unit. It has the precisely centered sighting hole and crosshairs of a sight tube, plus the cutout in the side of the tube containing the very precise 45° angle reflecting surface of a Cheshire . . .
Our Product #: 4550
Celestron Product #: 94182
 

Product Description

The Celestron Newtonian reflector collimating tool is a combination of a sight tube and a Cheshire tool in a single unit. It has the precisely centered sighting hole and crosshairs of a sight tube, plus the cutout in the side of the tube containing the very precise 45° angle reflecting surface of a Cheshire tool. As it is a combination tool, it is less expensive than buying a separate sight tube and Cheshire tool. However, it is a little more difficult to use than the two tools individually, as the 45° reflecting surface adds an extra visual element that some people find difficult to ignore when it is being used as a sight tube.

Collimating the optics of a commercial reflecting telescope by eye (as many people think is easily done) can be very frustrating. First, the diagonal mirror must be properly positioned and aligned with the primary mirror. You cannot assume that the diagonal mirror has been properly set up at the factory, or that it was not knocked out of alignment during shipping. If the diagonal is indeed out of position or alignment, collimating the primary mirror becomes difficult, even with the aid of a collimating tool such as the Cheshire. This is particularly true with fast focal ratio (f/4 to f/5) reflectors, as even slight collimation errors in these systems can significantly degrade the image.

The sight tube function of the tube allows you to first set the basic mechanical alignment of the diagonal mirror in its proper location in the light path using the crosshairs. It then allows you to aim the diagonal mirror accurately at the center of the primary. Once you've set the position and orientation of the diagonal mirror with the sight tube function, the Cheshire tool function is used to properly align the primary mirror. The Cheshire function can also be used to collimate the lenses of those refractors that have an adjustable lens cell.

The sight tube/Cheshire tool combination generally provides accurate enough collimation for visual use and most photography. The Celestron collimating tool is primarily designed to be used in daylight or early twilight, but the Cheshire function can also be used in complete darkness (for those times when you can't set up until late) by shining a red flashlight into the 45° reflecting cutout in the side of the tube. Instructions on how to use the Celestron collimating tool are included.

Tech Details

Weight 7 oz
Warranty 2 years

Reviews

Review by:
I use this collimator routinely with my 10” f/5 and 12.5” f/5 Dobsonians and it works well. I use it in conjunction with a 2” to 1.25” compression ring centering adapter, which gives a more true positioning of the collimator tube and more accurate collimation. Recommended. (Posted on 10/28/2019)
Review by:
I've used this tool to collimate several newtonians. It's simple to use and well made being all metal, unlike some plastic versions I've used. A nice and effective tool to have around. (Posted on 9/26/2019)
Review by:
I got this tool because my older laser collimator wasn't working well on my new larger scope (laser aperture too large). Even following the directions, it took me a bit to understand correct usage. I had to ask others in my club to verify what I was doing. Once it was clear that what I was doing was right, the tool makes it easy to accurately collimate. Not as easy as a laser on my old scope, but quite accurate, and straightforward when you know how. (Posted on 9/9/2019)
Review by:
Everyone need one of these in the toolbox. Very helpful when aligning Newts and I have used it to make sure refractor focusers are aligned too. Well made and simple to use. (Posted on 1/3/2019)
Review by:
You will probably not need to use this often, but if you need it this is the type to buy.
It is child's play to look through the peep and align the optics of your mount with the internal cross hairs. You should do this in daylight if you have traveled to a remote site because transporting the scope can throw off your optical alignment,

This type is better than the laser ones because you just don't need batteries, and it's cheaper.

For a fast Newtonian, if you don't align your optics you will get poor quality stars that look like seagulls. Use this and problem solved.
(Posted on 1/3/2019)
Review by:
This is a good, simple collimation tool. No frills means nothing to go wrong (e.g. dead battery or misaligned laser) . I recommend it. (Posted on 12/27/2018)
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