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astro-tech AT 80 EDT

from Astronomy Technologies

Thank you for choosing our Astro-Tech 

AT 80 EDT

 high-

performance apochromatic triplet ED refractor.

While some observers might doubt that you can get

apochromatic performance from an 80mm scope that is

as inexpensive as the Astro-Tech AT80EDT, we can say

only that seeing is believing.

The images from its fully-multicoated 560mm f/7 ED

(Extra-low Dispersion element) premium Ohara glass

triplet optics are virtually color-free, even at high

Aperture

.............................................. 80mm (3.1”)

Focal Length

...............................................560mm

Focal Ratio

........................................................ f/7

Objective Type

.............. triplet using Ohara ED glass

Optical Coatings

........................... fully multicoated

Resolving Power

 

(Dawes’ Limit)

....... 1.45 arc seconds

Visual Limiting Magnitude

.............. 12.0 maximum

Light Grasp

 

(versus the eye)

.............................. 131x

Field Stops

......... glare-reducing baffle in optical tube

Focuser

.............................dual-speed Crayford-type

with 11:1 reduction ratio fine focus;

2” and 1.25” compression ring eyepiece holders;

360° rotating camera angle/observing angle adjuster

Focuser Travel

................................... 3.1” (80mm),

millimeter scale on drawtube for repeatable focus

Lens Shade

............................................ retractable

magnifications. At its low price, we believe you will find

that the visual and photographic performance of your

AT 80EDT triplet is little short of remarkable.

This instruction sheet will provide you with information

on how to get the most out of your new refractor, and

how to properly maintain your scope so it can give you a

lifetime of observing enjoyment.

Please familiarize yourself with your telescope’s parts

and functions before operating it for the first time.

Astro-Tech AT 80 EDT Apochromatic Triplet Refractor Specifications

Objective Lens Cover

.........................slip-on metal

Tripod Mount

.. removable combination L-bracket and

dovetail for direct mounting on Celestron, Meade,

and Vixen equatorial mounts; two 1/4”-20 thread

mounting holes for photo tripod use

Tube Diameter

...................................... 90mm o. d.

Tube Length

 

(lens shade retracted)

..... 17.75” (451mm)

Tube Length

 

(lens shade extended)

... 20.25” (514mm)

Optical Tube Weight

................... 6.75 lbs. (3.07 kg)

Case

............................. aluminum-frame foam-fitted

lockable hard case, with carrying handle

Case Dimensions

.................22.25” x 12.75” x 8.25”

Lowest Usable Power

............ 14x (40mm eyepiece)

Highest Terrestrial Power

.......80x (7mm eyepiece)

Highest Practical Power

........ 140x (4mm eyepiece)

Theoretical Maximum

........... 187x (3mm eyepiece)

Retractable

dew shield

Lock knob for

focuser drawtube

1/4”-20 thread

tripod mounting holes

in base of reversible

bracket

Combined equatorial mount
dovetail and L-bracket
tripod mounting shoe

PARTS OF THE AT80EDT

Left coarse
focus knob

Fine

focus

knob

Focusing

scale on

focuser

drawtube

2” eyepiece

lock knob

Dust cover

1.25” eyepiece

lock knob

Brass compression ring

Mounting point for

optional finder

1.25”

eyepiece

lock knob

2”

eyepiece

holder

Locking collar for 360°

rotatable focuser

1.25” eyepiece

lock knob

Fine

focus

knob

Right

coarse

focus

knob

1.25”

eyepiece

adapter

1.25”

eyepiece

adapter

Right

coarse

focus

knob

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