Telescope-Collimation Tools-Apertura Cheshire Collimation Eyepiece

Using Your Eyepiece with a Newtonian Reflector
The Newtonian Reflecting telescope is one of the most popular telescope designs on the market. A Newtonian reflector uses primary and secondary mirrors to focus and direct light into the eyepiece. The primary mirror is the larger focusing mirror near the bottom of the OTA, and the secondary mirror is the smaller elliptical flat mirror just behind the focuser at the top of the OTA. Once these are accurately aligned, you increase the likelihood that your telescope will deliver it’s full observation potential. Check out our downloadable guide in the “Product Attachements” tab or view our Cheshire Collimation Eyepiece Guide Article to learn how to use this handy Apertura tool!

Large Aperture End with Stainless Steel Crosshairs
On the end of the Apertura CCE, there is an oversized large diameter, with a large area reflector (1.125″). The crosshairs are made of bright, large-diameter stainless steel wires. These wires are superior to the commonly used copper wires, as they are more robust due to their thicker size. You will not have to worry about the crosshairs bending with the premium Apertura collimating eyepiece! The stainless steel crosshairs are also bright and easy to see. They are less prone to corrosion, allowing you to use your collimating eyepiece longer. The crosshair cartridge can be removed from the main housing for cleaning or replacement if needed.

Long Tube
Apertura designed this collimating eyepiece with a long tube in order to provide you with greater accuracy potential. This potential is available due to the separation of the crosshairs from the eyepiece’s viewing hole. The stop collar is far back on the Cheshire eyepiece, allowing the tube to be inserted deep into the focuser, and providing the best of both worlds when it comes to collimation eyepieces: The long distance between the eyepiece and crosshairs and the ability to have the view port close to the top of the focuser. These two performance capabilities mean you can have a better alignment and fill view when aligning the secondary mirror.

Comes with the Apertura Absolute Warranty!
The Apertura Absolute Warranty provides two years of coverage against product defects. After the initial two-year warranty expires, this product qualifies for Apertura’s Three-Year Accident Replacement Program. In addition, the Apertura Absolute Warranty is transferrable! Download a copy of the Apertura Absolute Warranty for more information on this program, how to make a claim, and why it is important to keep your original receipt and the product’s original boxes & packaging!