ozzysmb

If your Mak have nonstandard 44.5mm thread (as mine have) ,you will need adapter to convert it to standard SCT thread, like this one : http://www.scopestuff.com/ss_smsa.htm Then use any 2'' visual back. One of better ones would be this one, bcs it will secure heavy load of your bino : https://www.highpointscientific.com/william-optics-rotolock-2inch-visual-back-with-sct-2inch-threads-d-roto-a2-sct2f

Hi, I got the William Optics 1.25" 90 degree Erecting Prism and must say its great upgrade from stock diagonal I got with my Skywatcher Mak 127. Feature this diagonal has is helical focuser with 15mm of travel. Tho, its not the feature I need really. Question is , is there a way to lock it in one position, so it will not turn ? On picture you can see diagonal and I marked with red arrow the small hole present, maybe for locking ? Tho, I didnt got additional screw for it.