This diagonal uses a thick, over-sized mirror polished to 1/10th wave. The mirror has a protective, dielectric coating with 99% reflectivity. The body has carbon fiber sides. It has a collet type twist lock on the 2" eyepiece tube and the deluxe 1.25" compression ring adapter is included. Both the two inch insert tube and adapter have filter threads. These diagonals are double tested at Stellarvue for perfect alignment and performance.
Star diagonals are a critical component of any refractor. The performance of an otherwise excellent telescope can be seriously compromised using a diagonal that is misaligned or pinched. Each diagonal and erecting prism we sell is tested for alignment and will preserve the exceptional quality of your Stellarvue telescope.
The D1028 uses a twist lock collet. Rotate the twist lock lever counter-clockwise to open. Insert the 1.25” adapter or 2” eyepiece and then rotate the lever clockwise to tighten.
The two inch insert tube has filter threads and a safety taper that will more accurately seat the diagonal and tend to keep it from falling out accidentally. Make sure you tighten the lock screw(s) when installing the diagonal in a focuser.
Your diagonal comes with a 1 1/4” adapter allowing you to use
1 1/4” eyepieces. The adapter uses a compression ring and has an insert safety groove and filter threads. Some Barlows have a long insert tube. Always check before using them to make sure they do not strike the mirror.