The images from its 550mm f/6.8 ED air-spaced doublet optics are virtually color-free, even at very high magnifications. While the color correction of the AT80ED qualifies it as a true apochromatic scope, we don’t claim it is quite the equal of a multiple thousand dollar Takahashi, Astro-Physics, or TMB refractor. However, the optics of this compact telescope are so good that you’ll have trouble telling it from one of those ultra-premium scopes. At its low price, its optical performance is little short of astonishing.

The AT80ED is an 80mm (3.1”) aperture, 550mm focal length, f/6.8 focal ratio air-spaced doublet. It uses an ED (Extra-low Dispersion glass) element to reduce spurious color halos and fringing to vanishingly low levels. The objective lens uses the latest state-of-the-art antireflection multicoatings on all four 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.

There are ten contrast-enhancing light baffles in the optical tube, for 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.

The AT80ED’s precision-made Crayford-style focuser has dual focusing speeds. There are two coarse focusing knobs. The right knob also has a smaller concentric knob for an 11:1 ratio reduction gear microfine focusing. This provides exceptionally precise image control during high power visual observing or 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. The focuser 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 lock knob under the focuser lets you lock in your photographic focus.

The focuser drawtube terminates in a 2” eyepiece holder with a soft brass compression ring to hold 2” star diagonals and camera adapters in place. The compression ring won’t scratch the barrel of your star diagonal as an ordinary thumbscrew can. The supplied 1.25” eyepiece adapter slips into the 2” drawtube and also uses a non-marring soft brass compression ring to hold 1.25” star diagonals and accessories in place.

The AT80ED has a removable L-shaped dovetail mounting shoe/tripod adapter. The 1.75” wide x 2.85” long mounting shoe is sized and shaped (with slanted sides) to fit the dovetail slot on the head of many equatorial mounts. It will fit, without modification, Celestron CG-5 and Advanced Series mounts, Meade LXD-75 mounts, and Vixen Great Polaris and Sphinx mounts, among others.

In addition, the mounting shoe has two 1/4”-20 thread mounting holes that allow it to be installed on any camera tripod that has a standard 1/4”-20 thread mounting bolt. The two mounting holes allow you to balance the weight of a camera or heavy 2” eyepieces and accessories. The front hole balances the scope for 1.25” diagonal and 1.25” eyepiece use with the lens shade extended. The rear hole balances it when a camera or a 2” diagonal and 2” eyepiece are mounted. Cork pads on the underside of the mounting shoe help keep the scope from swiveling when mounted on a tripod.

Two hex head bolts hold the mounting shoe in place on the 90mm diameter optical tube. This allows the shoe to be removed and reversed to better balance very tail-heavy accessory combinations. Removing the mounting shoe also lets you install the 90mm diameter tube of the AT80ED in optional mounting rings for use on an equatorial mount or as a piggyback photoguide or super finder.

A self-storing 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 to the effect of 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 scope measures 18” long with the dew shield retracted and 20.75” long with it extended.

The optical tube is available in your choice of either a black or blue anodized finish to suit your personal preferences. Both colors are set off by a black focuser and gloss black trim. A slip-on metal dust cover is standard. The AT80ED comes in a foam-fitted 22.5” x 12.5” x 7.5” aluminum-frame hard carrying case that has cutouts for the scope, a 1.25” or 2” star diagonal, and up to five eyepieces (three 1.25” and two 2”).

If this Astronomy Technologies AT80ED was just another 80mm refractor, the quality of its apochromatic optics alone would still make it a superb value. Add the premium features – like the dual speed microfine focuser, your choice of colors, and a hard case – and you have a scope that has no equal at its very affordable price.

As an expression of the confidence we have in the quality of our Astronomy Technologies products, the Astro-Tech AT80ED is protected by a two-year limited warranty against flaws in materials and workmanship.