Astro-Tech AT60EDP 60mm f/5 Dual ED Petzval OTA

This Astro-Tech AT60EDP refractor astrograph has:

• 60mm f/5 fully multicoated four-lens Petzval refractor
• Two ED lens elements, FCD-100 and FK-61
• 44mm corrected image circle
• amazing flat field astrophotographic capabilities
• dual-speed 2.8" rack-and-pinion focuser with 10:1 ratio fine focusing
• 48mm t-thread focuser back
• rotating camera angle adjuster
• Mounting Shoe with Vixen Style Dovetail and top handle
• sliding lens shade
• finderscope mounting shoe

This unique apochromatic ED petval refractor astrograph has a four lens fully-multicoated optical system. It uses two ED elements in its configuration, and has a wonderful flat field inherent in the petzval design.  

The Astro-Tech AT60EDP astrograph provides an exceptionally flat field for very wide images that are sharp edge-to-edge, with no need for a separate field flattener. This instrument is designed as an astrograph.  It can't be used visually.

Astro-Tech uses two ED (Extra-low Dispersion glass) elements in the optical design of the AT60EDP. The result 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 visible in lesser scopes. 

Those exceptional optics are even more impressive when you consider the package they come in. The finely-machined AT60EDP has a dual speed 2.8" 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 rear of the instrument is threaded so you can have the most secure connection possible.  The scope is as portable as portable can be.  With a tube length of 10.5" with the dew shield retracted or 12.75" with it extended, and fitting in a carry case that is 8.5" x 8.5" x 13", you surely won't notice it taking up much space wherever you go.  Weighing in at 6 pounds 14 ounces you can feel the quality of the instrument.

Features of this Telescope . . .

Apochromatic petzval Dual ED refractor optics: the objective lens is a 60mm (2.36") aperture, 300mm focal length, f/5 focal ratio petzval using two elements of ED (Extra-low Dispersion glass), one FCD-100 and the other is FK-61, to reduce spurious color halos and fringing to vanishingly low levels. The petzval design has an extremely flat field 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 eliminates the need to buy the separate external field flattener that most refractors need to provide flat field images.  The AT60EDP produces a 44mm image circle.

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 there is excessive ambient light at night, such as a neighbor's backyard security light. 

Dual speed 2.8" rack-and-pinion focuser with threaded camera connection: 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. The focus knobs have ribbed gripping surfaces so they are easy to operate, even while wearing gloves or mittens in cold weather.

The 2.8" 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 your camera allowing you frame your image however you like. A knob on the camera angle adjuster lets you lock the focuser at whatever angle provides the most pleasing photographic composition.

The 2.8" diameter focuser drawtube has a scale marked in 1mm increments, with 20mm of travel, 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 48mm t-thread back will unthread from the camera angle adjuster allowing you to thread a 28mm/2" filter into the underside of the back that you just unthreaded.

Tube finish: The optical tube and lens shade are finished in a matte black accented with a silver trim ring.

Tube rings and dovetail: The AT60EDP comes with a mounting shoe that attaches to a Vixen-style dovetail.  They will also let you attach the rings to optional Vixen- or Losmandy-style dovetail adapters for piggybacking the AT60EDP on top of a larger scope. The AT60EDP also comes with a handle for ease of mouting and carrying the instrument around.  The handle has arca-swiss capabilities.

Other supplied accessories: A slip-on metal dust cap is standard. There is a dovetail shoe on the upper left side of the optical tube for installing an optional multiple reticle red dot finder such as the Astro-Tech #ATF, using a #ATFBV base.  A carry bag is also standard equipment.

• Dust covers
• Tube rings
• Vixen-style dovetail
• Rotating camera angle adjuster
• 2" and 1.25" compression ring accessory holders
• Finder scope mounting shoe