Astrotech 111mm f/7 White Refractor Telescope
This 111mm triplet refractor from Astrotech has an increase of 18% light transmission when compared to a 102mm refractor ota. This telescope is a huge investment, as it can save you a maximum of $800 dollars for a telescope with better optics and light transmission as opposed to other refractors with similar apertures. Featuring Ohara glass, this refractor delivers sharp images that can avoid chromatic aberration.
Astrotech has packaged this refractor with two new and important accessories. They've reduced the aluminum tube from 124mm to 114mm and have added a dual-speec 2.7" Crayford focuser (11:1 focusing ratio) which makes this 11.2 pounds instead of 15. The focuser can rotate 360° to place your camera and/or eyepiece as desired and the 2" and 1.25" eyepiece holders feature non-marring compression rings to safely mount your eyepieces. Since unwanted external light can also be a problem, the Astrotech AT111EDT also has retractable lens shades.
Joe Nastasi - Parallax Instruments
“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.”
- ED Apochromatic 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.
- 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 114mm diameter 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. A lock knob keeps the dew shield from sliding when the scope is pointed at the zenith.
- Dual speed microfine 2.7” linear Crayford focuser - The newly-designed precision-made Crayford 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. The focuser drawtube has 80mm of travel and has a scale on top to let you return to an approximate focus when switching between visual and photographic setups. A tension knob under the focuser lets you adjust the focuser to accommodate varying equipment loads and lock in your photographic focus. The new linear bearing focuser has a polished stainless steel drive rail that runs the length of the underside of the drawtube. The focuser’s stainless steel drive shaft presses on this drive rail to move the focuser, rather than having the hard steel drive shaft press directly on (and wear out) the softer aluminum drawtube as with conventional Crayford focusers. The steel drive rail rides in a self-lubricating track that extends almost the entire length of the focuser body. The drive rail and its attached drawtube are thereby supported over most of their length at all times, rather than by a conventional Crayford focuser’s two sets of small contact area roller bearings. This system distributes the drive force evenly over the entire drawtube, without concentrating it on a few small contact points. The result is a very rigid drawtube with essentially zero flexure and no wear (much less flat spots or uneven wear) on the focuser drawtube.
- Two built-in camera angle adjusters - The 2.7” focuser can be rotated 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. Simply loosen a knob on the top of the focuser, rotate the focuser to whatever angle is most convenient for you, and then tighten the knob to lock the focuser at the desired angle. In addition to the entire focuser rotating, the focuser drawtube’s 2" eyepiece/accessory holder is itself a built-in camera angle adjuster that lets you quickly make final small adjustment tweaks to the angle of your camera or star diagonal without having to disturb the heavier focuser proper. This camera angle adjuster is standard equipment, not an optional extra-cost accessory, as it is with some other scopes. A knob on the 2" eyepiece/accessory holder lets you unlock the accessory holder, rotate it to the desired final angle, then lock it in place at whatever angle is most convenient for you. Many observers will find this camera angle adjuster to be even more convenient that the focuser rotation system and will use this method of adjusting the viewing angle exclusively.
- 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 1.25" 99% Reflectivity dielectric mirror diagonal). It's a Sky & Telescope Hot Product for 2007. An Astro-Tech guaranteed 1/10th wave peak-to-valley accuracy 2” quartz star diagonal (#AT2DQ1 one-piece machined 2" diagonal with 1/10th wave quartz mirror). Machined out of a single block of aluminum, with premium coatings, it 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.
- Tube rings - No tube rings are supplied for the 114mm o. d. optical tube, as some observers may already have rings for this size tube. If rings are needed, however, optional 114mm Astro-Tech #AT114R hinged tube rings are readily available.
- Other supplied accessories - There is a mounting point 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).
|Name||Astro-Tech - White 111mm f/7 ED Triplet Refractor Telescope|
|Highest Useful Magnification||222x|
|Limiting Stellar Magnitude||12.7|