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. We do not use a twist lock lever on the 1 1/4" adapter since it is more difficult to use. Some Barlows have a long insert tube. Always check before using them to make sure they do not strike the mirror. The 2" female insert tube on this diagonal will accept 41mm or 1.61" of nose piece length before hitting the built in safety stop. If your 2" nose piece is longer than this specified distance, the nose piece will not fully insert, though this is rarely an issue. The D1028ECF adds 4.1" or 104mm to the optical path.
The thick mirror is easier to access for cleaning. Simply remove the siz screws using a 2 mm Allen wrench and pull off the carbon fiber side plates. Push on one side of the mirror and it will slide out the other side.
Hold the mirror only by the back and edges. Never touch the surface. Remove the loose dust from the surface with air from a bulb syringe or bulb blower such as a “Rocket Blower.” Using a soft camel hair brush about 1’ wide while blowing with the bulb blower will help remove particles.
Never blow on the surface as your breath, canned air or from an air compressor as moisture drops will spot the surface.
Once you have removed particles, apply reagent grade acetone to a lens cloth. Gently and very slowly draw the cloth across the mirror. Do not apply too much pressure when wiping the surface or you will scratch the mirror or coating. Follow precautions necessary when using acetone. Be advised that in cleaning the mirror, you will not end up with a pristine surface if you wipe too fast. With time you will learn how to avoid streaks. Some residual streaks may remain so only do this cleaning if necessary.
