Colli-Mate Deluxe combined Cheshire and sight tube collimating eyepiece.
Simply the best, most precise, visual tool for collimating your telescope.
Benefits over laser collimator Much has been written on the respective merits of laser collimators over sight tube and centering eyepiece tools for collimating telescopes - it is certainly true that the primary function of telescopes is for looking through and not shining lasers through and it certainly makes a lot of practical sense to use collimating aids that rely on the principle of eye-views.
Aligning the mirrors seems easy enough in theory, but in practice it can be difficult without the proper tools. A common way of establishing "rough" collimation is to simply remove the eyepiece and look down the focuser tube to center the mirror reflections. The accuracy of this method is not very reliable. For one thing, there is no way to be sure that you are looking straight down the focuser tube. Another problem is being sure when the reflections of the mirrors are exactly centered, and merely peering into the focuser like this is not precise enough; the reflections may appear to be centered when in fact they are not.
The Astro Engineering Colli-Mate Deluxe collimating eyepiece will take care of both of these problems, allowing you to achieve precise collimation without the guesswork and thus improve your telescope´s performance.
Winning combination The Colli-Mate Deluxe collimating eyepiece is a combination of a sighting tube and Cheshire eyepiece. The sighting tube´s narrow field of view and crosshairs provide a centering reference for the telescope´s optical elements. The Cheshire eyepiece has a means of providing illumination to a target face (set at 45 degrees to the illuminating hole) that will be used to collimate the primary mirror.
Wide application The need for user-collimation most commonly applies to Newtonian reflectors and Schmidt-Cassegrain telescopes (SCTs) though the collimating eyepiece can be usefully employed with refractors, Maksutov-Cassegrain and other telescope designs.
Extra feature A useful feature of the Colli-Mate is the addition of an engraved target on the polished target face. This is useful to check the accuracy of the position of the focuser (on Newtonian instruments in particular), as the reflected image of the wire crosshairs at the bottom of the eyepiece tube should be perfectly superimposed on the engraved lines on the target face. (No other collimating eyepiece that we know of has this feature).
The AE Colli-Mate Deluxe combined Chesire and sight tube collimating eyepiece offers an ideal solution to keep your Newtonian or other telescope in perfect collimation. The Colli-Mate Deluxe has an anodised blue finish and is supplied with full instructions.
Comment from dealer's website: the instructions with this collimator are almost worth buying on their own - they are the best set of instructions we've seen for collimating Newtonian telescopes.