Astro-Tech AT6M Manual

astro-tech
A T 6 M
Thank you for choosing the 6" f/12 Astro-Tech AT6M
Rumak-type Maksutov-Cassegrain catadioptric optical
system.
This instruction sheet will provide you with informa-
tion on how to get the most out of your new Maksutov-
THE PARTS OF YOUR AT6M
8 x 50mm finder
in quick release
bracket
Dust cap
Aperture .................................................... 150mm (6")
Focal Length .................................................. 1800mm
Focal Ratio ............................................................. f/12
Optical Type .......... Rumak-type Maksutov-Cassegrain
Mirrors ..................................... both BK7 optical glass,
aluminized and overcoated with quartz
Corrector Lens ............ BK7 optical glass, multicoated
Secondary Mirror Obstruction ..... 57mm in diameter,
Resolving Power
(Dawes' Limit)
Visual Limiting Magnitude .................. 13.4 maximum
Your Astro-Tech AT6M Maksutov-Cassegrain is usable for day
and night viewing simply by adding a star diagonal and eyepiece. Any
brand of eyepiece can be used, from a 2" 55mm for the lowest prac-
tical magnification (33x) to a 6mm (300x) for very high power use.
Both 2" and 1.25" accessory adapters are supplied that thread onto
the rear cell of your AT6M to let you use optional 2" or 1.25" star
diagonals, image erecting diagonals, photo accessories, etc.
The focal length of your AT6M is ideal for high resolution/high power
views of the Moon, planets, binary stars, and globular star clusters.
Excellent views of the brighter nebulas, galaxies, and comets are also
routine over a wide range of magnifications.
To calculate the magnification of an eyepiece on the AT6M, divide
the scope's focal length in mm by the eyepiece focal length in mm.
For example, a 10mm eyepiece in your AT6M will give you a magnifi-
cation of 180x (1800mm/10mm = 180).
Astronomical Observing: The theoretical maximum usable power
available from this telescope is 360x, although this requires a 5mm
Astro-Tech AT 6M Maksutov-Cassegrain Specifications
38% by diameter, 14.4% by area
.......... 0.77 arc seconds
from Astronomy Technologies
Cassegrain optical tube, and how to properly maintain
your telescope so it can give you a lifetime of observing
and imaging enjoyment.
Please familiarize yourself with your scope's parts and
functions before operating it for the first time.
Thread-on
2" accessory
holder
Collimation
screw covers
(2 of 3)
Slip-fit
T-adapter
Slip-fit 1.25"
accessory
adapter
Vixen-style dovetail
(under optical tube)
T-adapter
Thread-on
SCT adapter
1.25" accessory adapter
Tube Diameter ................................. 6.7" (170mm) o. d.
Tube Length
Tube Weight
Mounting System ........ 7.85" long Vixen-style dovetail
Focuser ............... 28-turn knob moving primary mirror
Finder ........... 8 x 50mm stright-through dark crosshair
Lowest Usable Power ............... 33x (55mm eyepiece)
Highest Terrestrial Power ...... 100x (18mm eyepiece)
Highest Practical Power ........... 300x (6mm eyepiece)
Theoretical Maximum ............... 360x (5mm eyepiece)
eyepiece that provides a narrow and very dim 0.42mm exit pupil. A
more practical maximum magnification for astronomical viewing with
the AT6M would be 225x, using an 8mm eyepiece. Keep in mind that
seeing conditions play an important role in how high a magnification
you can use on any given night. Only very good seeing conditions
(clear skies and calm air) will support viewing at 225x and above.
Under less than ideal conditions, lower powers in the 100x to 150x
range provide more consistently usable and pleasing images.
The widest possible field of view is about 1.5°, which can be
achieved with a 2" 55mm (33x) Plössl eyepiece.
Astrophotography: The long focal ratio of the AT6M does not
lend itself easily to long exposure deep space imaging. However, the
AT6M does an outstanding job of lunar and planetary imaging, either
using a DSI-type CCD solar system imaging camera or eyepiece pro-
jection with a DSLR camera or CCD imager.
Terrestrial Observing: The AT6M can be used for long distance
daytime birding and nature studies if mounted on a suitable high
8 x 50mm finder
in quick release
(with 2" accessory adapter)
... 14.2 lbs. (6.45 kg)
(with finder & 2" adapter)
finder in quick release bracket
bracket
2" accessory
holder
Focus
knob
SCT
adapter
.... 21.5" (546mm)