This 90° 2” mirror-type star diagonal has enhanced aluminum mirror coatings for 96% reflectivity. The mirror is overcoated with quartz for long life. The diagonal is designed for refractors with 2” focuser drawtubes, but will also work with Schmidt-Cassegrains by adding optional rear cell adapter #7785C. This diagonal also includes the high hat 2" to 1.25" adapter. This high hat step-down adapter allows the use of 1.25" eyepieces in 2" focuser drawtubes and 2” star diagonals. The body of the adapter has a non-reflective matte satin black finish. The 2" barrel of the adapter has an undercut groove that the star diagonal/focuser thumbscrew sits in when tightened down. The extra depth of this groove reduces the chance of the adapter falling out of the focuser should the thumbscrew loosen. To keep your eyepieces looking new, 1.25" eyepieces are held in the adapter by a non-marring soft brass clamp ring rather than an ordinary aluminum thumbscrew that contacts the barrel directly. The thumbscrew that tightens the clamp ring is tethered internally in the adapter so that the thumbscrew can’t be lost in the field.
The mirror housing and its 2” focuser and eyepiece holder barrels are precision-machined from a single block of solid aluminum, rather than being simply a pair of less-rigid tubes screwed into a flimsy plastic mirror housing or sheet metal stamping, as is the case with lesser diagonals. A solid metal backplate over 4/10ths of an inch thick holds the mirror securely in place to assure permanent collimation of the diagonal’s parts. The 2” barrel that fits into the focuser or visual back is internally antireflection threaded for higher contrast. It is also threaded to accept standard 2” (48mm) filters. A groove cut into the outside of the 2” barrel acts as a safety stop to keep the diagonal from falling should the scope’s visual back or eyepiece holder thumbscrew loosen slightly from cold or use. The 2” eyepiece barrel uses a non-marring soft brass compression ring to hold eyepieces in place, rather than a thumbscrew that contacts the eyepiece barrel directly.
This is a very high quality 2” diagonal that is visibly superior in optics and workmanship to the economy and mid-priced 2” diagonals available from telescope manufacturers. It's a worthy upgrade for virtually any Schmidt-Cassegrain, Maksutov-Cassegrain, or refractor that uses a 2” star diagonal.
Tech Details:
Supplied Accessories:
2" to 1.25" high hat eyepiece adapter
