How to use an optical pole finder?
The pole finder is an accessory for equatorial mounts that allows you to quickly set the mount’s polar axis. When the polar axis is precisely set, an equatorial mount allows you to track an object while rotating along only one axis (right ascension). If the polar axis is not set accurately, the object will gradually “drift” in the field of view and additional correction will be required along two axes at once. Accurate polar axis alignment is especially important for long exposure photography. There are various ways to set the polar axis (drift method, auto-targeting system, electronic pole finders, etc.), however, in my opinion, the optical pole finder is still a simple and fast option, especially for small mounts -trackers, and also if it is not possible to carry a laptop or microcomputer with you.
The optical pole finder is a small lens telescope that consists of a lens, an eyepiece and a special reticle located in the field diaphragm of the eyepiece. The pole finder is designed to simultaneously show Polaris and the reticle clearly in the eyepiece. To adjust the sharpness of the reticle, simply rotate the eyepiece around its axis. The pole finder can also be equipped with a reticle illumination. The image in the finder is upside down, this is normal and has already been taken into account.
…