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

Adjusting the collimation while keeping an eye on the star in the eyepiece or on your screen is easy if you don’t need any tools. These adjustment screws for a 10-inch SCT from Bob’s Knobs replace the three collimation screws on the secondary holder. You just turn the knobs.

The set is made for 10 inch Schmidt-Cassegrain telescopes with f/10 and a secondary holder with three screws. So first, count how many screws are on your holder.

Replace the screws one by one. This way the secondary mirror stays in place and you only have to adjust a little later. Always turn a small bit and check the star again in between. Meanwhile, keep the corrector plate dry with a rainband for 9 and 10 inch.

If you see six screws, choose the 10 inch set for six screws.