The Astro-Tech AT102ED is a fantastic value and incredible performer.
This Astro-Tech AT102ED refractor has:
• 102mm f/7 fully multicoated doublet optics using FK-61 ED glass
• dual-speed 2" Rack and Pinion focuser with built in rotator
• 2" and 1.25" brass compression ring eyepiece holders
• split tube rings with detachable Vixen-style dovetail for installation on virtually any mount
The AT102ED is bringing ED optics to you at a fantastic price. When this scope was available in 2008 the retail price was $995. The reintroduction not only has a much lower price, but it has better mechanics as well as advancements in the optical assembly and polish. You get a 2" Rack and Pinion focuser with a microfine 11:1 fine-focusing ratio finished in our Aston Martin Grey body. You get dual split mounting rings with a detachable 8" Vixen-style dovetail plate that lets you mount your AT102ED on virtually any altazimuth or German equatorial mount. The finely-machined Astro-Tech AT102ED comes with both 2" and 1.25" eyepiece holders using non-marring brass compression rings that won’t scratch your star diagonal or eyepiece barrels.
As with all Astro-Tech scopes, the AT102ED gives you fully-multicoated ED optics that are essentially free of the annoying halo of unfocused violet light (chromatic aberration) that mars the bright-object images of lesser scopes, despite the fast focal ratio, and even at very high magnifications.
Features of this Telescope . . .
ED doublet refractor optics: 102mm (4") aperture, 714mm focal length, f/7 focal ratio doublet optical system using an FK-61 ED (Extra-low Dispersion glass) element to reduce spurious color halos and fringing to vanishingly low levels.
Fully multicoated optics: The AT102ED objective lens has the latest state-of-the-art antireflection multicoatings on all air-to-glass surfaces for high light transmission and excellent contrast. This can easily be seen by looking into the objective lens of the scope. Virtually no reflection of your face will be seen. It’s a sure sign that the high transmission coatings are doing their job, by letting virtually all the light enter the scope, rather than reflecting some light back to your eye.
Internal light baffles: Three contrast-enhancing knife-edge internal light baffles and a specially darkened tube interior provide truly dark sky backgrounds and high terrestrial contrast. The edges of the lenses are blackened to reduce internal reflections and further improve image contrast.
Dew shield: A retractable dew shield slows the formation of dew on the lens in cold weather to extend your undisturbed observing time. It also improves the contrast, similar the lens shade on a camera lens, when observing during the day or when there is excessive ambient light at night, such as a neighbor’s backyard security light. The tube measures 24” long with the dewshield retracted and 30" long with it extended.. A slip-on metal dust cap for the dew shield is standard.
2" Rack and Pinion rotating dual-speed focuser: The precision-made no-backlash dual speed 2" rack and pinion focuser is based off our EDT line of telescopes. Very smooth, and very robust. There are two coarse focusing knobs. The right knob also has a smaller concentric knob with an 11:1 reduction gear microfine focusing ratio. This provides exceptionally precise image control during high magnification visual observing and critical 35mm or CCD imaging. The focus knobs have ribbed gripping surfaces so they are easy to operate, even while wearing gloves or mittens in cold weather.
Long focuser travel: The long 85mm (3.35") travel of the focuser drawtube helps keep the overall scope length reasonable for convenient travel and storage. The long drawtube length also permits switching between visual or photographic use with no add-on extension tubes needed. The drawtube has a scale marked in 1mm increments so you can note individual focuser positions for easy return to the correct focus when switching between visual use and photography. A drawtube lock knob underneath the focuser lets you lock in your photographic focus.
Compression ring eyepiece holders: The focuser’s drawtube terminates in a 2" eyepiece holder that uses a non-marring soft brass compression ring to hold a 2" star diagonal and/or accessories in place. The compression ring won’t scratch the barrel of your star diagonal and accessories as an ordinary thumbscrew can.
A supplied 1.25" accessory adapter slips into the 2" eyepiece holder to let you use a 1.25" star diagonal, image erecting diagonal, or photographic accessories. Like the 2" eyepiece holder, the 1.25" adapter also uses a non-marring soft brass compression ring to hold 1.25" star diagonals and accessories in place. If you are partial to 1.25" eyepieces and need an outstanding diagonal for this scope, consider the 99% reflectivity Astro-Tech 1.25" dielectric diagonal #AT1D. It's a Sky & Telescope Hot Product for 2007. An Astro-Tech 2" dielectric star diagonal #AT2D will give you the same 99% reflectivity performance with 2" eyepieces.
Tube finish: The optical tube and lens shade are finished in a white powder coat while the focuser and trim are Aston Martin Grey anodized. The scope weighs 9.1 lbs with mounting rings attached.
Tube rings and dovetail mounting plate: The 105mm o. d. body of the AT102ED comes with a pair of hinged split mounting rings and a detachable 8" long dovetail mounting plate. The dovetail plate fits directly into the head of many equatorial and altazimuth mounts. It will fit, without modification, Celestron Advanced Series and Meade LXD-75 go-to mounts; the Vixen Porta altazimuth mount; and Vixen Great Polaris and Sphinx mounts, among others. The longer length of the dovetail plate lets you balance the AT102ED more easily fore and aft in a mount’s dovetail slot. This lets you quickly accommodate changing balance conditions as you exchange an eyepiece for a camera, a 1.25" diagonal for a 2" diagonal, etc.
In addition, the dovetail plate can be unbolted from the split rings to allow you to mount the rings directly on other equatorial mounts – for example on the D-plate used on Losmandy mounts – something that is difficult to do with the short mounting foot on competitive clamshell rings. The dovetail plate also has a 1/4"-20 thread mounting hole that allows it to be installed on any suitable heavy-duty camera tripod that has a standard 1/4"-20 thread mounting bolt.
The included 27" x 12" x 8" cordura nylon case has room for some accessories and provides great protection for your telescope.
