Astro-Tech ED Four Element 65mm f/6.5 Apochromatic Refractor
- 65mm f/6.5 fully multicoated four-lens/two-group (triplet/singlet) refractor
- two ED lens elements, including an FPL-53 element in the objective
- 110mm of backfocus
- amazing flat field astrophotographic capabilities
- 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 Vixen-style dovetail
- sliding lens shade with lock knob
- finderscope mounting shoe
- two-year warranty
This unique apochromatic ED quad refractor astrograph has a four lens/two group/two ED element fully-multicoated optical system. It uses an FPL-53 element in its apochromatic triplet objective lens, and has a separate field-flattening proprietary ED singlet lens at the rear of the optical tube.
The very sensibly-priced Astro-Tech AT65EDQ astrograph provides an exceptionally flat field for very wide DSLR and CCD deep space images that are sharp edge-to-edge, with no need for a separate field flattener. While designed primarily as an astrograph, it can also be used visually with a 1.25” star diagonal and eyepieces.
To see an image taken by Jason Blaschka showing the wide field imaging capabilities of the AT65EDQ, click here or on the feature image link below showing the Lagoon and Trifid nebulas. M31, the Andromeda Galaxy and its companion galaxies, is another of Jason’s AT65EDQ images. Click here to see it or click on the feature image link below.
To see an impressive image of the North American Nebula showing the flat field capability of the AT65EDQ, taken by Luke Leege, click on the NGC7000 feature image links below. Click here or on the 433kb medium size version below first, to get an overall impression, then click here or on the 1.6mb version below and examine the tight stars in the corners of the image, showing the scope’s flat field capability. The original image is 16mb in size. The NGC700 image was take by Luke using a Canon EOS 7D DSLR camera. Luke took 12 five minute exposures and 7 ten minute exposures with appropriate darks and flats. He combined them using Deep Sky Stacker freeware and processed the result in Photoshop CS3
Another good example of the AT65EDQ’s capability in the hands of an experienced astrophotographer is Jeremy Vandermeer’s image of the Rosette Nebula, also found in the feature images links below. It was taken from the light-polluted suburbs of Chicago. Jeremy combined 47 separate 240 second exposures taken with a modified Canon T1i to produce the final image, which we think compares quite favorably with professional images taken with much larger and more expensive scopes. Jeremy said about the AT65EDQ, “this scope is great.” So is Jeremy’s image.
Can you take images as good as these with a 65mm scope? At the low price of the AT65EDQ it won't cost you a fortune to try your hand at wide field astrophotography.
Other manufacturers often use FPL-51 ED glass or its equivalent in their more-expensive triplet designs to keep their manufacturing costs down, or use FPL-53 in a simple doublet. In comparison to this approach, Astro-Tech uses a more-expensive true FPL-53 ED (Extra-low Dispersion glass) element in the triplet objective lens of the modestly-priced AT65EDQ. 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. In addition, a fourth lens of a proprietary ED type acts as a field flattener for wide field imaging.
Those exceptional optics are even more impressive when you consider the package they come in. The finely-machined AT65EDQ has a dual speed 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.
If this Astro-Tech AT65EDQ was simply a top-quality 65mm FPL-53 ED doublet system, it would be fairly priced. But – a 65mm fast focal ratio quadruplet astrograph using true FPL-53 glass, with a dual-speed 2” rack and pinion focuser and a built-in ED field flattener at this price . . . is the kind of super value only Astro-Tech can give you!
Features of this Telescope . . .
- Apochromatic quadruplet ED refractor optics: the objective lens is a 65mm (2.56”) aperture, 420mm focal length, f/6.5 focal ratio triplet using an element of high quality FPL-53 ED (Extra-low Dispersion glass) to reduce spurious color halos and fringing to vanishingly low levels. In addition, there is a separate ED glass singlet lens at the rear of the optical tube that acts as a field flattener 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.
- 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 4.75 pound AT65EDQ measures a very compact 13” long with the dew shield retracted, and is only 14.25” long with it extended.
- Dual speed 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 DSLR 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 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 62mm (2.44”) travel 2” diameter 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. If you are partial to 1.25” eyepieces and need an outstanding diagonal for this scope, consider the Astro-Tech 1.25” dielectric diagonal (#AT1D). It's a Sky & Telescope Hot Product for 2007. Most 2” star diagonals will not reach infinity focus with the AT65EDQ with either 1.25" or 2" eyepieces, so a 1.25” diagonal is recommended for visual use.
- Tube finish: The optical tube and lens shade are finished in a durable textured powder coat, the same as that used on scopes three times the price of the AT65EDQ. The focuser and trim are black anodized.
- Tube rings and dovetail: The AT65EDQ comes with a pair of felt-lined 80mm hinged split mounting rings with 1/4”-20 thread mounting holes in the top and bottom of each ring, plus a Vixen-style dovetail. Supplied mounting bolts let you install the rings on the supplied dovetail or on an optional Losmandy-style “D-plate” dovetail for using the AT65EDQ on an equatorial mount. They will also let you attach the rings to optional Vixen- or Losmandy-style dovetail adapters for piggybacking the AT65EDQ on top of a larger scope. A 1/4”-20 thread mounting hole in the Vixen-style dovetail will let you mount the AT65EDQ on an optional standard photo tripod for use as a terrestrial spotting scope or telephoto lens.
- 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.
- Two year warranty: As an expression of the confidence Astronomy Technologies has in the quality of their products, the Astro-Tech AT65EDQ quadruplet astrograph is protected by a two-year limited warranty against flaws in materials and workmanship.
|Name||Astro-Tech - ED Four Element 65mm f/6.5 Apochromatic Refractor|
|Manufacturer Part No||AT65EDQ|
|Telescope Aperture||3" and Under|
|Highest Useful Magnification||140x|
|Optical Tube Weight||5.65 lbs.|
|Resolution||1.78 arc seconds|