Meade Instruments Astro-Tech AT80LE - Manual

astro-tech AT 80 LE
from Astronomy Technologies
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.
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 80LE 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.
Astro-Tech AT 80 LE Refractor Specifications
Retractable
dew shield
Lock knob
for focuser
drawtube
90mm split rings,
with 1/4”-20 thread
mounting holes
top and bottom
PARTS OF THE AT80LE
Left coarse
focus knob
Fine
focus
knob
Focusing
scales on
focuser
drawtube
2” eyepiece
lock knob
Dust cover
1.25” eyepiece
lock knob
Brass compression ring
Mounting points for
optional finder
2” eyepiece
holder
1.25”
eyepiece
lock knob
Fine
focus
knob
Right coarse
focus knob
1.25”
eyepiece
adapter
1.25” eyepiece
adapter
Right
coarse
focus
knob
Tension
adjustment
knob for
focuser drawtube
2” eyepiece
lock knob
Dew shield
lock knob
1.25” eyepiece
lock knob
Dust cap
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) ......... 1.45 arc seconds
Visual Limiting Magnitude .............. 12.0 maximum
Light Grasp (versus the eye) ................................ 131x
Field Stops ... 2 glare-reducing baffles in optical tube,
one at front of dew shield
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
Optical Tube Diameter ......................... 90mm o. d.
Tube Length (lens shade retracted) ......... 15.5” (394mm)
Tube Length (lens shade extended) .......18.75” (476mm)
Weight
(optical tube only)
..................5.15 lbs. (2.34 kg)
Weight (with rings and 1.25” adapter) ...6.55 lbs. (2.98 kg)
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
lockable hard case, with carrying handle
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)