THIS PRODUCT HAS BEEN DISCONTINUED. THIS PAGE IS HERE FOR INFORMATIONAL PURPOSES ONLY.
If you are looking for the best fast focal ratio/compact APO refractor that Thomas Back and Roger Ceragioli could create, then look no further.
This Astro-Tech AT92 refractor has:
• 92mm f/5.5 apochromatic triplet optics using an ED/Lanthanum combination
• collimatable lens cell for peak imaging and optical performance
• 2.5" dual-speed rotating rack and pinion focuser
• ultra-short 16.5" length for travel
• 2" and 1.25" compression ring eyepiece holders
• retractable dew shield, dust covers, and 20.5"x9.5"x9" hard case
• CNC tube rings and a Vixen dovetail
The AT92 92mm f/5.5 triplet apo is a very compact refractor for the serious observer and traveler. Measuring only about 16.5" long with the focuser and dewshield retracted for storage and travel, the AT92 optically and mechanically fills the void left by the discontinued TMB-92 and 90mm f/5 Astro-Physics Stowaway (a legendary scope that sells for up to $6000 on the used market).
The AT92 puts exceptionally high optical and mechanical quality in a truly tiny package. It is ideal for the serious observer who will accept nothing less than unsurpassed imaging and visual observing performance in a supremely portable body you can take with you anywhere in the world.
The AT92 is a continuation of the legendary TMB92. Thomas laid the foundation for this scope when we had him design his ultimate refractor, the TMB-92 Signature Series. The design has set dormant in our "vault" for the past 5 years or so until we thought it was time to dust it off. We sent the design to Roger Ceragioli to give it a once over and make sure that it was performing as it should with advances in glass and coatings over the last decade. He studied it, and made some changes to try and get every ounce of performance possible out of 92mm of glass.
The AT92 is an exceptional grab and go scope for observing and imaging - both within the solar system and out to the furthest reaches of infinity. Its images of subtle low-contrast lunar and planetary details are razor-sharp, with realistic and highly saturated color. Those images are free from chromatic aberration of any type, thanks to the ED element in the scope's triplet optics.
The latest antireflection multicoatings and knife-edge internal baffles assure the maximum image contrast possible. Image excellence is limited only by the seeing conditions, not by any aberration or short-coming in the telescope.
This Telescope's Optical and Mechanical Systems . . .
Apochromatic triplet ED refractor optics: 3.6" (92mm) aperture, 506mm focal length, f/5.5 triplet lens. It uses an ED (Extra-low Dispersion) glass center element in combination with a rear Lanthanum element for a sharp images that are high in contrast and free from spurious color (chromatic aberration).
Multicoated optics: Fully multicoated on all surfaces with the latest antireflection materials for exceptionally high light transmission and excellent contrast. Light transmission is so high that the optics seem to virtually disappear when viewed from head on.
Internal light baffles: Contrast-enhancing knife-edge light baffles in the optical tube and focuser provide truly dark sky backgrounds and high terrestrial contrast. In addition, the edges of the objective lens are blackened to eliminate contrast-reducing stray internal reflections.
Retractable dew shield: The self-storing retractable dew shield/lens shade slows the formation of dew on the lens to extend your undisturbed observing time. It also improves visual and photographic contrast by shielding the lens from off-axis ambient light (the neighbor's yard light, moonlight, etc.)
Dual-speed 2.5" rotating rack and pinion focuser: The precision-made 2.5" focuser has dual-speed focusing. There are two coarse focusing knobs. The right knob also has a smaller concentric knob with a 10:1 reduction gear microfine focusing ratio. This provides exceptionally precise image control during very high magnification visual observing, and during critical 35mm or CCD imaging. All focus knobs are ribbed, so they are easy to operate, even while wearing gloves or mittens in cold weather. Multiple internal baffles in the focuser drawtube assure high contrast.
Compression ring eyepiece holders: The focuser drawtube ends in a 2" eyepiece holder that uses a non-marring soft brass compression ring to hold a 2" star diagonal and accessories in place. The compression ring won't scratch the barrel of your star diagonal and accessories as an ordinary thumbscrew can. Also supplied is a 1.25" eyepiece holder that slips into the 2" compression ring holder to let you use a 1.25" star diagonal or image erecting diagonal. Like the 2" eyepiece holder on the eyepiece holder rotation mechanism, the 1.25" adapter also uses a non-marring soft brass compression ring to hold 1.25" star diagonals and accessories in place.
Shipping/storage case: The AT92 comes standard in a 20.5"x9.5"x9" aluminum frame locking hard case with a carry handle for transportation and general protection purposes. Astro-Tech is one of the very few manufacturers to provide a case at no charge for protection during shipping and as a storage convenience when the scope is not in use. Unfortunately, FedEx, UPS, and the Postal Service are very good at treating packages roughly. Occasionally, your scope can arrive in perfect condition, but with the walls of the shipping case dented in transit from rough handling, or the aluminum frame sprung, rendering the appearance of the case less than pristine. Damage to the shipping case in such instances is not covered by warranty.
Full Dimensions: 19" long with dew shield extended. 16" long with dew shield retracted. Dew Shield diameter 4.75". 108mm tube diameter. 7.25 pounds.
Other supplied accessories: A slip-on metal dust cap is standard. As well as a set of hinged tube rings and a Vixen dovetail.
