Collimating Eyepiece for Refractor Telescopes, Short Collimator
Collimating Eyepiece for Refractor Telescopes, Short Collimator, Cheshire Collimator
This collimating eyepiece (collimator) is for 31.7mm, 1.25” eyepieces.
It is a Cheshire-type collimating eyepiece for refractors (lens telescopes) that can easily replace your usual eyepiece for quick collimation and adjustment.
The collimating eyepiece has a shiny metallic, sloping ( under 45 ) surface with a hole in the middle. Through the hole you can see through to the front lense. As it is more practical to use it in daytime, please leave the lens cover on to make sure that the reflection could be seen.
When looking through the hole, the sloping, shiny surface will be seen as a shiny circle in the middle. In the case of a well collimated refractor there will be two reflections, which lie on top of each other, and are centred in the middle of the picture.
Please note: your lens cover is usually non-transparent plastic or metal, but in the case it's transparent, please use a dark piece of cloth to cover it.