Refractors

More Information  · Supplied Accessories  · Recommended Accessories  · Images of Some Features Price $1,595.00 $1,895.00 SAVE: $300.00 (15%) Shipping $29.95 Highest Useful Magnification 222x Visual Limiting Magnitude 12.7 Focal Length 777mm Focal Ratio f/7 Resolution 1.04 arc seconds Aperture 4.37" Net Weight 14.7 lbs. Warranty 2 years

• 111mm f/7 fully multicoated triplet apochromatic optics using an ED element and all Ohara glass
• collimatable lens cell
• dual-speed 2.7" rack-and-pinion focuser with 11:1 ratio fine focusing
• both 2" and 1.25" brass compression ring eyepiece holders
• retractable lens shade/dew shield
• long-lasting white paint finish with anodized grey trim
• aluminum-frame hard case
• two-year warranty

    With an aperture of 111mm (4.37"), this Astro-Tech AT111EDT ED triplet apochromatic refractor gathers over 18% more light than the more common size 102mm (4") refractors. Combine this extra light gathering with the Astro-Tech AT111EDT’s state-of-the-art optical multicoatings, and you have a scope that outperforms similar (but more costly) competitive 102mm and 110mm refractors – and at a price as much as $800 less than a similar competitive scope!

    Astro-Tech uses only premium Ohara glass in the apochromatic triplet optics of the AT111EDT. This results in images that are essentially totally 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.

    These exceptional optics are even more impressive when you consider the package they come in. The finely-machined scope has a dual speed 2.7" rack-and-pinion focuser with a microfine 11:1 fine-focusing ratio. The focuser can rotate a full 360° to put your camera or eyepiece in the most comfortable observing position. The supplied 2" and 1.25" eyepiece holders use non-marring brass compression rings that won’t scratch your eyepiece barrels. The Astro-Tech AT111EDT has a retractable lens shade and comes in a locking aluminum-frame hard carrying case.

    This feature-laden 111mm Astro-Tech ED triplet apochromatic refractor is priced hundreds of dollars less than competitive 102mm and 110mm scopes. At the price, and for the exceptional performance, it is an absolute steal!

    Here are some comments about the AT111EDT from an owner, Joe Nastasi of Parallax Instruments. Joe is an experienced astronomer, well-known for making some of the finest cost-no-object large aperture classical Cassegrain and Dall-Kirkham Cassegrain optical tubes and equatorial mounts available to the amateur astronomer.

    “I was in the market for a portable, high quality apochromat for my visual planetary study and decided on the Astro-Tech AT-111. I was thrilled when Pete informed me that he had one in stock! Upon receipt of the instrument, I was impressed by the quite good looks of the telescope. After performing a quick star test, it was apparent the collimation was dead on. After performing numerous other tests, I must say that the triplet optics are of the highest quality with as near perfect color correction as I have ever seen. A few nights ago, I enjoyed a few hours of excellent quality seeing and atmospheric transparency. The detail visible on Jupiter was stunning to say the least. The instrument delivered exceptional contrast and sharpness with belts and zones clearly defined. The extremely difficult swirls and polar mottling could occasionally be glimpsed. Quite extraordinary for a 4.37" telescope. In addition, the standard camera angle adjuster is a real joy, especially when using a binoviewer. All in all, I’m very pleased with this telescope and can’t wait to get my hands on the 6" that's being considered." – Joe Nastasi, Parallax Instruments

Features of this Telescope . . .

• ED apochromatic triplet refractor optics: 111mm (4.37") aperture, 777mm focal length, f/7 focal ratio three-lens optical system using an ED (Extra-low Dispersion glass) element to reduce spurious color halos and fringing to vanishingly low levels. All three lens elements are precision ground and polished from the finest quality Ohara glass. Ohara is well-known as Japan’s premier manufacturer of specialized optical glass.

• Collimatable lens cell: The push/pull lens cell is fully collimatable in the field for peak performance. A simple optional Cheshire eyepiece and your own eyes are all you need.

• Fully multicoated optics: The triplet 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: Contrast-enhancing knife-edge light baffles in the lens shade and the optical tube 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 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 tube measures a compact 23.75" long with the dew shield retracted.

• Dual speed microfine 2.7" rack-and-pinion focuser: 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 a 11:1 reduction gear microfine focusing ratio. This provides exceptionally precise image control during high magnification visual observing and critical CCD imaging. The focus knobs have ribbed gripping surfaces so they are easy to operate, even while wearing gloves or mittens in cold weather.

• Built-in camera angle adjuster: The 2.7" 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 focuser a full 360° to line up a camera in either a landscape or portrait orientation (or any orientation in between), as well as put a star diagonal and eyepiece into the most comfortable observing position. A knob on the camera angle adjuster lets you lock the focuser at whatever angle is most convenient for you.

• Extra-long focuser travel: The extra-long 138mm (5.4") travel 2.7" diameter focuser drawtube helps keep the overall scope length as short as practicable for convenient travel and storage. The tube measures only 23.75" long with the lens shade retracted, and 28" long with it extended. The extra-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 lock knob on top of the focuser lets you lock in your photographic focus.

• Compression ring eyepiece holders: The focuser’s 2.7" 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 Astro-Tech 1.25" dielectric diagonal (#AT1D). It's a Sky & Telescope Hot Product for 2007.
      An Astro-Tech guaranteed 1/10th wave peak-to-valley accuracy 2" quartz star diagonal (#AT2DQ) is recommended to deliver all of the scope’s exceptional optical performance to your eye.

• Tube finish: The optical tube and lens shade are finished in a durable high gloss automotive-style white paint, the same as that used on scopes several times the price of the AT111EDT. The focuser and trim are anodized gun metal grey. There is an anodized dark green identifying band around the camera angle adjuster portion of the focuser body.

• Tube rings: No tube rings are supplied for the 124mm o. d. optical tube, as some observers may already have rings for this size tube. If rings are needed, however, optional 124mm Astro-Tech #AT124R hinged tube rings are readily available.

• Other supplied accessories: There is a dovetail foot on the upper left side of the optical tube for installing an optional multiple reticle red dot finder (#ATF). A slip-on metal dust cap is standard, as is a dust seal for the eyepiece holder.

• Shipping/storage case: The AT111EDT comes in a locking hard aluminum-frame case with carry handle.
      Astro-Tech is one of the very few manufacturers to provide a case at no charge for protection during shipping and as a storage convenience when the scope is not in use. Unfortunately, FedEx, UPS, and the Postal Service are very good at treating packages roughly. Occasionally, your scope can arrive in perfect condition, but with the walls of the shipping case dented in transit from rough handling, or the aluminum frame sprung, rendering the appearance of the case less than pristine. Damage to the shipping case in such instances is not covered by warranty.

• Two year warranty: As an expression of the confidence Astronomy Technologies has in the quality of their products, the Astro-Tech AT111EDT triplet apo is protected by a two-year limited warranty against flaws in materials and workmanship (shipping case excluded).