Astro-Tech AT126EDQ f/7 Quad Refractor

This Astro-Tech AT126EDQ ED refractor has:

• 126mm f/7 fully multicoated four-lens/two-group refractor
• two ED lens elements
• amazing flat field astrophotographic capabilities and a 44mm image circle to boot
• dual-speed 2" rack-and-pinion focuser with 10:1 ratio fine focusing
• 2" and 1.25" non-marring compression ring accessory holders
• rotating camera angle adjuster
• split mounting rings with a handle and mini Vixen saddle plate with Vixen-style dovetail
• sliding lens shade
• finderscope mounting shoe

This unique apochromatic ED quad refractor astrograph has a four lens/two group fully-multicoated optical system. It uses an ED element in its apochromatic triplet objective lens, and has a separate field-flattening proprietary ED lens set.

The Astro-Tech AT126EDQ astrograph provides an exceptionally flat field for very wide deep space images that are sharp edge-to-edge, with no need for a separate field flattener. While original EDQ designed primarily as an astrograph, the AT126EDQ is just as adept visually as it is photographically.  So you have the best of both worlds!

The optical designers have been hard at work trying to supply you with a system that covers all the bases. The result of the four element design with two ED elements is the finest possible control of spurious color, for images that are free of all vestiges of the annoying faint color halos around bright objects.

Those exceptional optics are even more impressive when you consider the package they come in. The finely-machined AT126EDQ has a dual speed 3.2" rack-and-pinion focuser with a microfine 10:1 fine-focusing ratio. The standard equipment camera angle adjuster rotates a full 360° for the most pleasing photographic compositions. The supplied 2" and 1.25" accessory holders use non-marring brass compression rings that won't scratch your accessory barrels. The focuser also has a variety of threads for you to use as you wish.  From the basic 2” compression ring to the metric threads of M63, M54, and M48.

Features of this Telescope . . .

Apochromatic quadruplet ED refractor optics: the objective lens is a 126mm (4.96") aperture, 882mm focal length, f/7 focal ratio optical system using one ED element to reduce spurious color halos and fringing. In addition, there is a separate flattener using an ED element to eliminate the curved field typical of fast focal ratio doublet and triplet refractors. Stars are focused and point-like to the edges of the field. This built-in field flattener eliminates the need to buy the separate external field flattener that most refractors need to provide flat field images.  However, you can purchase the additional .8x reducer if you require a faster system.

Fully multicoated optics: All lenses have the latest state-of-the-art antireflection multicoatings matched to their glass types on all air-to-glass surfaces for high light transmission and excellent contrast.

Dew shield: 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 17.67 pound (including tube rings, dovetail, and handle) AT126EDQ measures 28.6" long with the dew shield retracted, and is 34.7" long with it extended.

Dual speed 3.2" rack-and-pinion focuser with 2" accessory holder and 1.25" accessory adapter, both with compression rings: The precision-made rack-and-pinion focuser has dual-speed focusing. There are two coarse focusing knobs. The right knob also has a smaller concentric knob with 10:1 reduction gear fine focusing ratio. This provides exceptionally precise image control during critical imaging sessions. The focus knobs have ribbed gripping surfaces so they are easy to operate, even while wearing gloves or mittens in cold weather.  The focuser is also electronic focuser compatible for products such as the ZWO EAF.

The 3.2" focuser drawtube terminates in a built-in camera angle adjuster as standard equipment. It is not an optional extra-cost accessory, as it is with some other scopes. The camera angle adjuster lets you rotate the 2" accessory holder to line up a camera in either a landscape or portrait orientation (or any orientation in between). A knob on the camera angle adjuster lets you lock the focuser at whatever angle provides the most pleasing photographic composition.

The focuser drawtube has a scale marked in 1mm increments so you can note individual focuser positions for easy return to the approximate correct focus when switching between visual use and photography or when switching between cameras. A lock knob under the focuser lets you lock in your photographic focus. The dual thumbscrew 2" drawtube has a 2" accessory holder that uses a non-marring soft brass compression ring to hold 2" accessories in place. The compression ring won't scratch the barrel of your accessories as an ordinary thumbscrew can.

A standard equipment 1.25" accessory adapter slips into the 2" accessory holder to let you use a 1.25" star diagonal, image erecting diagonal, or photo accessories. Like the 2" accessory holder, the 1.25" adapter also uses a non-marring soft brass compression ring to hold 1.25" accessories in place. 

Tube finish: The optical tube and lens shade are finished in a durable matte black anodize. The focuser and trim are black anodized with a few red appointments.

Tube rings and dovetail: The AT126EDQ comes with a pair of felt-lined hinged split mounting rings with M6x1 thread mounting holes in the top and bottom of each ring, plus a Vixen-style dovetail as well as a handle with a mini vixen saddle plate. Supplied mounting bolts let you install the rings on the supplied dovetail or on an optional Losmandy-style "D-plate" dovetail for using the AT126EDQ on an equatorial mount.

Other supplied accessories: A slip-on metal dust cap is standard. There is a dovetail shoe on the upper portion of the focuser of the optical tube for installing an optional finder or imaging accessory.  You telescope also comes in a cordura nylon style carry case with cutouts for various accessories.

Technical Details