Explore scientific ed80 collimation

[diegocolonnello (Diego)]

Hi people, i am having fun trying to find out what is wrong with an Explore Scientific ed80 that i found second hand. everything is in a wonderful shape but i think needs collimation. manuals explain how to do it adjusting the triplet objectives centering.

Anyone knows about a tool, techniques or someone who can do this?

thanks

[Emc2 (Jon)]

Are you sure the collimation needs adjusting? Refractors typically do not need this to be re-adjusted. Before you do anything, you need to be sure this is what is required here.
You can do a star check on the sky at high magnification and observe the airy disk, or get yourself an artificial star generator which let you do the collimation indoors by day.

[casstony]

Collimation can be adjusted indoors with an artificial star, with the aim being to get the first diffraction ring centered and of even thickness even all the way around. Refractors which don't have push-pull collimation screws might be improved by shimming the focuser.

If the problem is decentering resulting in coma you really need someone experienced to adjust the lenses - very small adjustments to the second or third lens are needed while observing coma at high power and there is a risk of chipping the lenses. Adjustments are made in line with the direction of coma, pushing the lens to reduce the coma.