1.25Inch Metal Collimating Cheshire Eyepiece- Long Version

Aligning the mirrors seems easy enough, in theory, but in practice it can be difficult without the proper tools. A common way of collimating—the “quick and dirty” method—is to simply remove the eyepiece and look down the focuser tube to center the mirror reflections. The accuracy of this method, however, is not reliable. For one thing, there is no way to know whether you are looking straight down the focuser tube; your line of sight could be off by a degree or two. Another problem is knowing when the reflections of the mirrors are exactly centered. Just “eyeballing it” isn’t precise enough; the reflections may appear to be centered when in fact they are not. The Collimating Eyepiece will take care of both of these problems, allowing you to achieve precise collimation without “guessing,” and thus improve your telescope’s performance. The Collimating Eyepiece is a combination of a “sight tube” and a “Cheshire eyepiece.” The sight tube’s narrow field of view and crosshairs provide a reference for centering the optical elements during the collimation process. A Cheshire eyepiece has a polished flat set in the barrel at a 45° angle, which directs light entering from a cutout in the side of the barrel down into the optical path. The Cheshire allows quick and easy collimation of the primary mirror, assuming the mirror has been marked with a spot exactly in its center. Using the Collimating Eyepiece Collimation can be performed in daylight, when it is easier to see what you’re doing. However, never point the telescope or the cutout side of the Collimating Eyepiece at, or anywhere near, the Sun, or serious and instant eye damage could result! Insert the Collimating Eyepiece directly into the 1.25" focuser. When using a 2" focuser, place the Collimating Eyepiece into a 1.25" adapter. If you use a star

• Fits in 1.25" focusers and easy to use;simply cap the telescope, remove the diagonal, and place the eyepiece directly in the focuser.
• For aligning optics of Newtonian reflectors, Dobsonian reflectors, and Schmidt-Cassegrain Telescopes (SCTs).
• Accurate collimation is essential for high power observing. Stars will become more like pin points of light, and Planetary / Lunar detail will be enhanced.
• Item was made by aluminum with crosshair at the bottom allow quick and precise centering of the optics.
• This collimation eyepiece can be used for precisely collimating the Newtonian and Schmidt-Cassegrain reflector telescopes for better image quality.