Meade AT111EDT - Manual

astro -tech
AT 1 1 1 E DT

f ro m A s t ro n o my Te ch n o l o g i e s

Thank you for choosing this

Astro-Tech AT 111 EDT

high-quality apochromatic triplet refractor.

The lenses in your scope’s 777mm f/7 air-spaced triplet

optics use Ohara glass exclusively, from Japan’s finest

glass manufacturer. They include an advanced ED (Extra-

low Dispersion) element to give you images that are

virtually color-free, even at very high powers. Thanks to

its computer-optimized optical design, top quality ED

Aperture

............................................ 111mm (4.4”)

Focal Length

............................................... 777mm

Focal Ratio

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

Objective Type

.............................. air-spaced triplet

using all-Ohara glass, including an ED element

Optical Coatings

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

Resolving Power

(Dawes’ Limit)

....... 1.04 arc seconds

Visual Limiting Magnitude

.............. 12.7 maximum

Light Grasp

(versus the eye)

.............................. 251x

Field Stops

.......................... three knife-edge baffles

Focuser

.......................... dual-speed rack and pinion

with 11:1 reduction ratio fine focus;

360° rotating camera angle/observing angle adjuster;

and 2” and 1.25” compression ring eyepiece holders

Focuser Travel

................................. 5.4” (138mm);

millimeter scale on drawtube for repeatable focus

glass, and high transmission multicoatings, the optical

performance of your AT 111 EDT is exceptional indeed.

This instruction sheet will provide you with information

on how to get the most out of your new Astro-Tech

refractor, and how to properly maintain it so it can give

you a lifetime of observing enjoyment.

Please familiarize yourself with the parts and functions

of your AT111EDT before using it for the first time.

Astro-Tech AT 111 EDT Apochromatic ED Triplet Refractor Specifications

Finder

.............. optional; mounting shoe provided for

Astro-Tech multiple reticle finder or similar finder

Lens Shade

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

Lens Shade Outer Diameter

....................... 150mm

Objective Lens Cover

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

Tube Diameter

.................................... 124mm o. d.

Tube Length

(lens shade retracted)

..... 23.75” (603mm)

Tube Length

(lens shade extended)

........ 28” (711mm)

Optical Tube Weight

................. 14.65 lbs. (6.66 kg)

Case

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

lockable hard case, with carrying handle

Case Dimensions

.......................... 28” x 10.25” x 9”

Lowest Usable Power

......... 19.4x (40mm eyepiece)

Highest Terrestrial Power

....... 86x (9mm eyepiece)

Highest Practical Power

........ 194x (4mm eyepiece)

Theoretical Maximum

........ 222x (3.5mm eyepiece)

Retractable dew shield

Lock knob for

focuser drawtube

Locking knob for 360°

rotatable focuser

PARTS OF THE AT 111 EDT

Left coarse
focus knob

Fine

focus

knob

Focusing

scale on

focuser

drawtube

1.25”

eyepiece

holder

1.25” eyepiece

lock knob

Dust cover

1.25” eyepiece

lock knob

Brass compression ring

Right

coarse

focus

knob

1.25”

eyepiece

holder

Mounting shoe for

optional finder

2” eyepiece

lock knob

2”

eyepiece

holder

2”

eyepiece

holder

1.25”

eyepiece

holder