Two new Astro-Tech EDX Triplet APOs have been introduced by Astronomics – the Astro-Tech AT90EDX f/6 Triplet APO and the Astro-Tech AT130EDX f/7 Triplet APO. The telescopes are an offshoot of the company’s popular Astro-Tech AT90CFT.
As Astronomics’ Mike Bieler notes about the scopes, “The EDX series started off as the AT90CFT. The 90CFT has fantastic optics even being referred to as a desert island scope. Pretty high praise. However, some people just don’t like carbon fiber and wanted a more traditional looking scope. So, back to the drawing board. I wanted the best optical set I could get my hands on and deliver guaranteed optics at a fair, if not great, price. I also wanted to make some changes, so it was not just a reskin of the 90CFT. First came the body of the scope, I went with our white and Aston Martin grey trim. Then I went to the focuser and made it larger. From there I made some changes to the tube rings and it now includes a Losmandy style dovetail as standard equipment. The one thing we didn’t touch was the optical set. It has been tremendous. I also wanted to make a larger scope, so the AT130EDX became a thing. It uses the same optical glass the 90 does and comes with the same .95 Strehl optical guarantee. It is a simply awesome telescope series.”
Each of the Astro-Tech EDX Triplet APOs use an FCD-100 ED (Extra-low Dispersion) glass center element in combination with two mating elements for sharp images that are high in contrast and free from spurious color (chromatic aberration). All three lens elements are slow polished for smooth surfaces, with less scattered light. Fully multicoated are included on all surfaces with the latest antireflection materials for exceptionally high light transmission and excellent contrast. As the Astronomic team notes, “Light transmission is so high that the optics seem to virtually disappear when viewed from head on.”
The optical tubes are constructed out of aluminum with Astro-Tech’s signature grey anodized metal trim and focuser body. Contrast-enhancing knife-edge light baffles in the optical tube and focuser provide truly dark sky backgrounds and high terrestrial contrast. In addition, the edges of the objective lens are blackened to eliminate contrast-reducing stray internal reflections.
The Astro-Tech AT90EDX comes with a dual-speed 3.2″ rotating rack and pinion focuser and the Astro-Tech AT130EDX with a dual-speed 3.7″ rack-and-pinion focuser (see more later in the article on each).
The self-storing retractable dew shield/lens shade slows the formation of dew on the lens to extend observing time. It also improves visual and photographic contrast by shielding the lens from off-axis ambient light (the neighbor’s yard light, moonlight, etc.)
Dual split hinged tube rings are supplied for each optical tube. The rings are lined with white felt that will not stain the white finish of the scope over time. A Losmandy-style dovetail is bolted to the bottom of the tube rings. The scopes also come with a handle on the top of the tube rings to help with carrying and mounting the optical tube.
Each of the Astro-Tech EDX Triplet APOs comes standard in a padded soft case with a carry handle and shoulder strap for transportation and general protection purposes. The soft case has ample padding to protect your scope and has five cutout spaces for various accessories like a diagonal or the optional .8x reducer/field flattener. A slip-on metal dust cap is standard as well.
Astro-Tech AT90EDX
The AT90EDX 90mm f/6 triplet is a very compact refractor for the serious observer and traveler. It specs out at 3.5″ (90mm) aperture, 540mm focal length and f/6 triplet lens while only measuring about 18″ long with the focuser and dewshield retracted for storage and travel.
The scope is 20.2″ long with dew shield extended and 17.5″ long with dew shield retracted. The Dew Shield diameter is 122mm and the tube diameter is 104mm. The OTA weighs in at 12.2 pounds with rings and handle.
The AT90EDX is an exceptional grab and go scope for observing and imaging – both within the solar system and out to the furthest reaches of infinity. Its images of subtle low-contrast lunar and planetary details are razor-sharp, with realistic and highly saturated color. Those images are free from chromatic aberration of any type thanks to the ED element in the scope’s triplet optics.
The Astro-Tech AT90EDX comes with a beefy dual-speed 3.2″ rotating rack and pinion focuser: There are two coarse focusing knobs. The right knob also has a smaller concentric knob with a 10:1 reduction gear microfine focusing ratio. This provides exceptionally precise image control during very high magnification visual observing, and during critical imaging sessions. All focus knobs are ribbed, so they are easy to operate, even while wearing gloves or mittens in cold weather. Multiple internal baffles in the focuser drawtube assure high contrast. The focuser comes standard with two Vixen style finder shoes as well as a built in Camera Angle Adjuster to really help frame perfect images.
The focuser drawtube ends in a 2″ eyepiece holder that uses a non-marring twist lock compression ring to hold a 2″ star diagonal and accessories in place. The compression ring won’t scratch the barrel of a star diagonal and accessories as an ordinary thumbscrew can. Also supplied is a 1.25″ twist lock eyepiece holder that slips into the 2″ compression ring holder to let you use a 1.25″ star diagonal or image erecting diagonal. Like the 2″ eyepiece holder on the eyepiece holder rotation mechanism, the 1.25″ adapter also uses a non-
Astro-Tech AT130EDX
The Astro-Tech AT130EDX offers 130mm (5.12″) aperture, 910mm focal length, and an f/7 focal ratio. The OTA is 20.75 lbs and it tops out at 24.55 lbs with tube rings, dovetail, and handle.
The dual speed 3.7″ rack-and-pinion focuser offers two coarse focusing knobs. The right knob also has a smaller concentric knob with a 10:1 reduction gear microfine focusing ratio. This provides exceptionally precise image control during high magnification visual observing and critical imaging. The focuser also has a payload capacity of 15 pounds, so even the heaviest load will not be an issue.
The focus knobs have ribbed gripping surfaces so they are easy to operate, even while wearing gloves or mittens in cold weather. The focuser has 100mm of travel as well as a millimeter scale on the drawtube to let you return to an approximate focus when switching between visual and photographic setups. A lock knob under the focuser lets you lock in your photographic focus.
The 3.7″ 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 the knob on the top of the focuser housing, 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 includes 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. 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 than the focuser rotation system and will use this method of adjusting the viewing angle exclusively.
The focuser’s 3.7″ drawtube terminates in a 2″ eyepiece holder that uses a non-marring 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 compression ring to hold 1.25″ star diagonals and accessories in place.
You can learn more about the Astro-Tech EDX Triplet APOs here.
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