Can't focus my telescope
If there is nothing on the objective lenses or eyepiece lenses then it most likely needs collimation. This is where you adjust the secondary mirror while viewing an out of focus star. You need stable sky conditions to do this.There are most likely three small screws at the front of the telescope and these are what you use to adjust it. As one screw is loosened then another is tightened. Do this in very small increments. If you have your manual it should outline how to perform this. If not go to this web site: http://www.astrosurf.com/legault/collim.html.
It will show examples of how objects look both in and out of collimation. There is a section further down the page for SCTs.A very handy tool for this is to replace your screws with Bob's Knobs (http://www.bobsknobs.com/
) . These replace the screws and allow you to adjust it by hand instead of a screwdriver.The other focusing problem I've experience with my Celestron SCT is to have the focus knob loosen up and then slip as I turned it so that I could never focus with it.Good luck and clear skies!-jodair Read More At : Meade...