The Sky-Watcher f/5.3 190mm Maksutov-Newtonian optical system is a quality fast focal ratio performer that excels at deep space imaging and viewing.
The exciting 7.5" f/5.3 Mak-Newt from Sky-Watcher is just what astrophotographers and serious deep space visual observers have been looking for. It uses a hybrid optical system that combines a Newtonian reflector's parabolic primary mirror with a Maksutov's spherical front corrector. The result is a system that corrects for both coma and spherical and chromatic aberrations.
The Maksutov-Newtonian design provides large aperture/fast focal ratio apochromatic performance similar to that of a fine refractor with exceptional field correction in a compact and affordable package. The small secondary obstruction yields a sharper and higher contrast image than a Schmidt-Cassegrain - both visually and photographically. The fast f/5.3 focal ratio makes the Sky-Watcher Mak-Newt an excellent wide field photographic instrument for deep sky imaging.
The optical tube is made of rolled steel, powder-coated gloss black, with gold fleck accents. The front and rear cells are painted die-cast aluminum. The front cell is perforated to allow faster cool down of the Maksutov corrector. A precision 2" Crayford focuser is standard. The smooth backlash-free focuser has both coarse and ultra-fine (10:1 ratio) focusing knobs.
Features of this 180mm Sky-Watcher Maksutov-Cassegrain . . .
Maksutov-Newtonian optics: 7.5" (190mm) aperture, 1000mm focal length, f/5.3. The optical system uses Pyrex mirrors (a parabolic primary and a diagonal flat). The parabolic primary mirror helps correct for spherical aberration. The diagonal mirror is attached directly to the Maksutov corrector, instead of being supported by a traditional Newtonian reflector's spider vanes. This eliminates the diffraction spikes typical of spider vanes to improve contrast. The Maksutov spherical corrector lens is made of premium Schott crown optical glass and is fully multi-coated on both sides with multiple layers of anti-reflection materials for high light transmission and good contrast. Internal baffling reduces stray light to further improve the contrast.
Focuser: Dual-speed 2" Crayford type with 10:1 ratio fine focusing.
2" eyepiece: The 36x eyepiece is a fully multi-coated three-element Sky-Watcher 28mm LET design with a long 20mm eye relief and a twist-up eyecup. The eyepiece field of view is 1.55° across, a little larger than three lunar diameters, for expansive views of nebulas, open and globular star clusters, and galaxies.
Finder: 9 x 50mm right-angle correct image dark crosshair achromatic refractor.
Mounting rings and dovetail: Dual split tube rings are attached to a Vixen-style dovetail bar for installing the scope on any altazimuth or equatorial mount that uses a Vixen-style saddle. The split rings let you adjust the rotation and fore and aft position of the scope relative to the mount for balancing the scope and adjusting the focuser to the most comfortable viewing and imaging position. A 1/4"-20 thread stud on the top of one of the tube rings lets you piggyback a camera onto the scope for wide-field photography.
Warranty: two years.
