iOptron Maksutov-Cassegrain User manual

iOptron Corporation | 6F Gill Street | Woburn, MA01801 | www.iOptron.com
iOptron®150mm
Maksutov-Cassegrain Optical Tube Assembly
INSTRUCTION MANUAL
WARNING!
NEVER USE A TELESCOPE TO LOOK AT THE SUN! Looking at or near the Sun will cause instant and irreversible
damage to your eye. Children should always have adult supervision while observing

iOptron Corporation | 6F Gill Street | Woburn, MA01801 | www.iOptron.com
Welcome to a new world of adventure!
The iOptron Rumak-type 150mm
Maksutov-Cassegrain comes with a dual
speed focuser for fine-tuning your images and
an attachable dew shield for better
performance in cold temperatures.
These instructions will help you set up and
properly use and care for your telescope.
Please read them over thoroughly before
getting started.
Getting Started
Your telescope comes fully assembled from
the factory. The optics have been installed
and collimated, so you should not have to
make any adjustments to them. Keep the dust
covers on the telescope when it is not in use.
Mounting the Telescope
The iOptron MAK 150mm is a perfect mate for
the iOptron MiniTower™ or MiniTower Pro™
goto altazimuth mount, or the SmartStar®-PR
goto equatorial mount. It has a Vixen-style
dovetail rail for mounting the scope quickly
and directly onto an altazimuth or equatorial
mount.
Use of Optional Accessories
Your telescope does not come with eyepieces
and diagonal so as to offer the greatest
flexibility in configuring it to your needs.
The 2” compression ring accessory holder
accepts 2” eyepieces, star diagonals, camera
adapters, etc. There are several accessories
that come with the MAK 150mm OTA. One is
a 1.25” compression ring adapter that slips
into the 2” holder. This lets you use optional
1.25” accessories (eyepiece, star diagonal,
camera adapter, terrestrial image erecting
diagonal, DSI-type camera, etc.) The second
is an adapter for Schmidt-Cassegrain
accessories. This lets you use any SCT
thread-on accessories you might already
have (star diagonals, camera adapters, etc.)
The third item is a standard T-adapter that
also slips into the 2” holder and lets you use a
DSLR for prime focus imaging.
Selecting an Eyepiece
Always begin viewing with the lowest power
eyepiece. (Note: a 20 mm focal length
eyepiece is lower power than a 10 mm one.)
A formula can be used to determine the power
of each eyepiece: Telescope focal length
divided by eyepiece focal length equals
magnification.
Ex. 1800mm ÷ 20mm = 90X (magnification)
Focusing Telescope
Point the telescope so the front end is aimed
in the general direction of an object you wish
to view. When you first look in the eyepiece,
the image you see may be fuzzy, or out of
focus. If so, gently turn the focus knob with
your fingers until the image becomes sharp.
Go a little bit beyond sharp focus until the
image just starts to blur again. Then reverse

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the rotation of the knob just to make sure
you’ve hit the exact focus point. You will have
to readjust the focus when aiming at subjects
of varying distances, or after changing
eyepieces. Turn the fine tuning knob for finer
adjustments.
If you have trouble focusing, rotate the focus
knob counterclockwise as far as it will go.
Now look through the eyepiece while slowly
rotating the focus knob clockwise. You should
soon see the point at which focus is reached.
(Please be patient turning the focus knob.
There are about 11 full turns from one end to
the other when using the larger/coarse tuning
knob).
Try to practice this during daytime by aiming
the main telescope tube at a land-based
target at least 200 yards away (e.g. A
telephone pole or building).
Aligning Finderscope
The supplied 8x50mm straight-through
finderscope comes with a quick-release
bracket. The dual-ring bracket has six
collimating screws for precise alignment with
the main scope optics. The quick-release
bracket slips into a dovetail mounting shoe at
the rear of the scope during use.
First, look through Main Telescope Tube and
establish a well-defined target (see focusing
telescope section). Tighten all lock knobs of
your mount (Declination, Latitude, Right
Ascension, and Horizontal Axes) so that
telescope’s aim is not disturbed. Then look
through the finderscope and adjust the six
collimation screws to center the object in the
finderscope. Now, objects located first with
the finderscope will be centered in field of
view of the main telescope.

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Specifications
Clear Aperture 150mm
Focal Length 1800mm
Focal Ratio f/12
Lens Type Catadioptric Rumak style Maksutov-Cassegrain
Resolving Power 0.77 arc seconds
Visual Limiting Magnitude 12.8
Finderscope 8x50 w/ finder ring
Dew Shield Twist-lock aluminum shield
Focuser Dual speed
Tube Length 21 3/4” (Without dew shield) 27 1/8” (With dew shield)
Tube Weight 13.4 lbs
Astrophotography T-ring adapter included for attaching a camera
Other Accessories 2” to 1.25” compression ring accessory holders;
Adapter Ring for Schmidt-CassAccessories
Dust Cover Light reducing lens cover
Gross Weight 20.2 lbs
Warranty Two year limited
Finderscope
Dual Speed
Focuser
Eyepiece
Adapter
Dovetail Plate
Dew Shield

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Revised May 2010