Astronomy Technologies Astro-Tech AT80LE Product Manual

astro-tech A T 80 LE
Thank you for choosing our Astro-Tech AT 80 LE high-
performance apochromatic doublet ED refractor.
Its carbon fiber tube and dew shield are exceptionally
durable, with excellent thermal characteristics. The dew
shield is oversized, with a 124mm o.d. compared to the
80mm lens diameter.
This assures that tube currents, which typically follow
the walls of a telescope tube, will have a minimal effect
on your images as the AT80LE cools down to ambient
temperature. You can begin serious observing with an
AT80LE sooner than you can with an aluminum tube
80mm doublet with a conventional dew shield design.
PARTS OF THE AT80LE
Fine
focus
2" eyepiece
knob
lock knob
Right coarse
focus knob
1.25"
eyepiece
lock knob
Tension
adjustment
knob for
focuser drawtube
Dust cover
Aperture .............................................. 80mm (3.1")
Focal Length ...............................................480mm
Focal Ratio ........................................................ f/6
Objective Type ...... doublet using Ohara FPL-53 glass
Optical Coatings ........................... fully multicoated
Resolving Power
(Dawes' Limit)
Visual Limiting Magnitude .............. 12.0 maximum
Light Grasp
(versus the eye)
Field Stops ... 2 glare-reducing baffles in optical tube,
Focuser ............................ dual-speed Crayford-style
with 10:1 reduction ratio fine focus;
2" and 1.25" compression ring eyepiece holders
Focuser Travel ............ 2.9" (74mm), with millimeter
and inch scales on drawtube for repeatable focus
Optical Tube Material .......................... carbon fiber
Dew shield
lock knob
90mm split rings,
Lock knob
with 1/4"-20 thread
for focuser
mounting holes
drawtube
top and bottom
Brass compression ring
1.25" eyepiece
lock knob
Astro-Tech AT 80 LE Refractor Specifications
......... 1.45 arc seconds
................................ 131x
one at front of dew shield
from Astronomy Technologies
The images from the AT80LE's fully-multicoated 480mm
f/6 ED doublet optical system (using premium Ohara glass
and an FPL-53 extra-low dispersion element) are virtually
color-free, even at very high magnifications. We believe
you will find that the visual and photographic performance
of your AT 80 LE doublet 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.
Retractable
Mounting points for
dew shield
optional finder
2" eyepiece
holder
1.25" eyepiece
adapter
Optical Tube Diameter ......................... 90mm o. d.
Tube Length
Tube Length
Weight
(optical tube only)
Weight
(with rings and 1.25" adapter)
Lens Shade ... retractable carbon fiber, with lock knob
Objective Lens Cover ......................... slip-on metal
Mounting Rings ............ dual 90mm felt-lined hinged
split rings with 1/4"-20 thread mounting holes
Case ............................. aluminum-frame foam-fitted
Case Dimensions ............................. 20" x 7.5" x 9"
Lowest Usable Power ............ 12x (40mm eyepiece)
Highest Terrestrial Power ....... 80x (6mm eyepiece)
Highest Practical Power ........ 160x (3mm eyepiece)
Theoretical Maximum ........... 160x (3mm eyepiece)
Left coarse
focus knob
1.25" eyepiece
lock knob
Dust cap
1.25"
eyepiece
adapter
......... 15.5" (394mm)
(lens shade retracted)
.......18.75" (476mm)
(lens shade extended)
..................5.15 lbs. (2.34 kg)
... 6.55 lbs. (2.98 kg)
lockable hard case, with carrying handle
Focusing
scales on
focuser
drawtube
Fine
focus
knob
Right
coarse
focus
knob
2" eyepiece
lock knob