Adjusting screws for the viewfinder of a 12 inch SCT f/10, 3 or 4 screws | Bob’s Knobs

With a large tube, the front isn’t always easy to reach, and you don’t want to have to use a small screwdriver to get to it. With these adjustment screws for a 12-inch SCT from Bob’s Knobs, you twist the collimation screws on the secondary holder with your fingers.

The set fits on 12 inches Schmidt-Cassegrain telescopes with f/10, the secondary holder has three or four screws. Before ordering, check how your holder looks like.

Replace the screws one by one so that the mirror stays in place, and then adjust the collimation to a bright star. If there is a clear night, you can also work with a artificial star for collimation.

On a humid evening, a rainbow band for 12 inch telescopes the corrector plate free of dew.