astro-tech
AT 1 0 2 E D
from Astronomy Technologies
Thank you for choosing this Astro-Tech AT102 ED high-
performance ED refractor.
The images from its 709mm focal length f/6.95 ED (Extra-
low Dispersion glass element) air-spaced doublet optics are
virtually color-free, even at high magnifications.
Its package of standard features – a dual-speed Crayford-
style focuser, an illuminated multiple reticle finder, tube rings
with a separate Vixen-style dovetail, hard case, and more –
Aperture .................................................... 102mm (4”)
Focal Length .................................................... 709mm
Focal Ratio ..........................................................f/6.95
Objective Type .... air-spaced doublet with ED element
Optical Coatings................................ fully multicoated
Resolving Power (Dawes’ Limit) ...... 1.14 arc seconds
Visual Limiting Magnitude .................. 12.5 maximum
Light Grasp (versus the eye) ............................... 212x
Field Stops ............ 3 knife-edge baffles in optical tube
Focuser ....................................... dual-speed Crayford
with 10:1 reduction ratio fine focus;
2” and 1.25” compression ring eyepiece holders;
360° rotating camera angle/observing angle adjuster
Focuser Travel ....................................... 3.35” (85mm)
with millimeter scale on drawtube for repeatable focus
Finder ........ non-magnifying illuminated multiple reticle
is unsurpassed at its sensible price. We believe you will
agree that the performance and features of your AT102ED
make it an exceptional value.
This sheet will provide you with information on how to
get the most out of your new scope, and how to maintain
it so it can give you a lifetime of observing enjoyment.
Please familiarize yourself with the parts and functions
of your AT102ED before operating it for the first time.
Astro-Tech AT102ED Apochromatic Refractor Specifications
Lens Shade ........................ retractable, with lock knob
Objective Lens Cover............................. slip-on metal
Tripod Mount ............... hinged split rings with dovetail
for Astro-Tech, Celestron, Meade, and Vixen mounts
Tube Diameter .......................................... 105mm o. d.
Tube Length (lens shade retracted) ........ 23” (584mm)
Tube Length (lens shade extended)..... 27.5” (699mm)
Optical Tube Weight .......................... 7.3 lbs. (3.32 kg)
Weight (w/dovetail, rings, finder) ..... 10.1 lbs. (4.59 kg)
Case .................... lockable aluminum-frame foam-fitted
hard case, with carrying handle
Case External Dimensions ......... 28.75” x 9.75” x 8.5”
Lowest Usable Power ..............
17.5x (40mm eyepiece)
Highest Terrestrial Power ..........
101x (7mm eyepiece)
Highest Practical Power .............
177x (4mm eyepiece)
Theoretical Maximum Power ..
203x (3.5mm eyepiece)
Retractable
dew shield
Tension adjustment
and lock knob for
focuser drawtube
Locking collar for
360° rotatable focuser
Detachable dovetail to fit Astro-Tech,
Celestron, Meade, and Vixen mounts
Split tube rings
PARTS OF THE AT 102ED
Left coarse focus knob
Fine
focus
knob
Focusing scale on
focuser drawtube
1.25”
eyepiece
adapter
1.25”
eyepiece
lock knob
Dust cover
1.25” eyepiece
lock knob
Brass
compression
ring
Right
coarse
focus
knob
1.25”
eyepiece
adapter
Alternate
finder
mounting
location
(slotted
head)
2” eyepiece
holder
Multiple reticle
illuminated finder
Multiple reticle
illuminated finder
Tube ring
lock knobs
Dust seal
Tube
rings
Lock knob for
retractable
dew shield
Hex-head
screws (do
not adjust)
2” eyepiece
lock knob
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