ORION TELESCOPES & BINOCULARS 9823 Installation and operating instructions

ADDENDUM
IN 183 Rev C 03/19
(#9823 shown)
Collimation of Orion Maksutov-
Cassegrain Telescopes
Español
Francais
Deutsche
Italiano
➊Pour obtenir le manuel d'utilisation
complet, veuillez vous rendre sur le site Web
OrionTelescopes.eu/fr et saisir la référence
du produit dans la barre de recherche.
➋Cliquez ensuite sur le lien du manuel
d’utilisation du produit sur la page de
description du produit.
➊Wenn Sie das vollständige Handbuch
einsehen möchten, wechseln Sie zu
OrionTelescopes.de, und geben Sie in der
Suchleiste die Artikelnummer der
Orion-Kamera ein.
➋Klicken Sie anschließend auf der Seite mit
den Produktdetails auf den Link des entspre-
chenden Produkthandbuches.
➊Para ver el manual completo, visite Orion-
Telescopes.eu y escriba el número de artí-
culo del producto en la barra de búsqueda.
➋A continuación, haga clic en el enlace al
manual del producto de la página de detalle
del producto.
➊Per accedere al manuale completo, visitare il
sito Web OrionTelescopes.eu. Immettere the
product item number nella barra di ricerca
➋Fare quindi clic sul collegamento al manuale
del prodotto nella pagina delle informazioni sul
prodotto.
Corporate Offices: 89 Hangar Way, Watsonville CA 95076 - USA
Toll Free USA & Canada: [phone]
International: [phone]
Customer Support: [email protected]
Copyright © 2020 Orion Telescopes & Binoculars.All Rights Reserved. No part of this product
instruction or any of its contents may be reproduced, copied, modied or adapted, without the
prior written consent of Orion Telescopes & Binoculars.
AN EMPLOYEE-OWNED COMPANY

Collimation is the alignment of a telescope’s optics with its
mechanical axis. Your Maksutov-Casegrain’s optics were colli-
mated at the factory and should generally not need adjustment
unless the telescope has been handled roughly. This manual
describes how to test the collimation of your telescope and pro-
vides step by step instructions for proper alignment should that
be needed.
I. Star-Testing the Telescope
Before you start adjusting the primary mirror of your telescope,
make certain that it is actually out of collimation by performing
a star test.
Take your telescope out at dusk and let it acclimate to the out-
side temperature; this usually takes 30-60 minutes. When it is
dark, point the telescope upwards at a bright star and accurately
center it in the eyepiece’s eld of view. Slowly de-focus the image
with the focusing knob. If the telescope is correctly collimated,
the expanding disk should be a circle (Figure 1). If the image
is unsymmetrical, the scope is out of collimation. Also, the dark
shadow cast by the secondary mirror should appear in the very
center of the out-of-focus circle, like the hole in a donut. If the
“hole” appears off-center, the telescope is out of collimation.
If you try the star test but the bright star you have selected is
not accurately centered in the eyepiece, the optics will always
appear out of collimation, even though they may be perfectly
aligned. It is critical to keep the star centered during the star test!
II. The Collimation Screws
On Orion Maksutov-Cassegrain telescopes only the primary mir-
ror’s tilt can be adjusted. The secondary mirror is xed in place
on the inside of the meniscus lens and cannot be adjusted.
To adjust the tilt of the primary mirror, you will use six collima-
tion screws on the rear cell of the telescope. On the smaller
Maks, the six screws are evenly spaced: three large screws that
alternate with three smaller screws (Figure 2a). On the larger,
150mm and 180mm Maks, the six screws are arranged in three
close pairs, with each pair consisting of one large and one small
screw (Figure 2b). The large and small collimation screws
work together to adjust the tilt of the primary mirror in a “push-
pull” fashion. One must be loosened and the other tightened by
equal amounts in order to adjust the mirror’s tilt.
The collimation screws are Allen head screws; you will need
metric Allen wrenches to turn these screws (sizes needed are
stated in the procedures below). Metric Allen wrench sets are
available at many hardware stores or on the internet.
III. The Collimation Procedure
The procedure for collimating an Orion Maksutov-Cassegrain
will be slightly different depending on whether it has the colli-
mation screws in three close pairs (for the 150mm and 180mm
Maks) or it has them evenly spaced (for the 90mm, 102mm,
and 127mm Maks). We will rst describe the procedure for the
smaller Maks, then in Section B we will cover the procedure for
the larger Maks.
A. Collimating the Orion 90mm, 102mm, and
127mm Maksutov-Cassegrains
Follow this procedure for Maksutov-Cassegrains having six
equidistant (evenly spaced) collimation screws on the rear cell,
as in Figure 2a.You will need a 3mm and a 2mm Allen wrench
to turn the collimation screws.
This procedure should be done indoors, with the telescope
pointed at a white wall in a well-lit room. Remove the diagonal
and eyepiece and look into rear opening of the optical tube (also
remove the dust cover from the front of the tube). Try to keep
your eye centered with respect to the rear opening of the tube
as best as possible. Using an Orion Collimating Eyepiece or a
Cheshire eyepiece will aid greatly in keeping your eye centered
and is strongly recommended.
If your telescope is out of collimation, the view will resemble
Figure 3a. A properly collimated scope will resemble Figure
3b. The direction of the misalignment in your telescope may dif-
fer from Figure 3a, but the diagram gives you the general idea
of how things will look.
Locate the black crescent near the outer edge of the eld of
view. The appearance of such a black crescent indicates that
the telescope is out of alignment. Note which way the front of
the telescope would need to move in order to “ll” that black
crescent and resemble Figure 3b. Then look at the back end
of the telescope and locate the collimation screw that is in the
Figure 2. a) Orion 90mm, 102mm, and 127mm Maks have six
evenly spaced collimation screws on the rear cell, whereas
b) Orion 150mm and 180mm Maks have three close pairs of
collimation screws.
a b
Figure 1. A star test will determine if a telescope’s optics are
properly collimated. An unfocused view of a bright star through the
eyepiece should appear as illustrated on right if optics are perfectly
collimated. If circle is unsymmetrical, as in illustration on left,
scope needs collimation.
Out of collimation Collimated
2

direction that the front of the telescope needs to move, or basi-
cally, the direction of the black crescent.
For example, if the view resembled Figure 3a, then you would
want to move the front opening of the telescope down.Thus, the
collimation screw you would start with would be the screw on
the bottom as shown in Figure 4a. Your actions now depend
on whether this collimation screw is a small or large screw.
Please note that you will be working to adjust the mirror cell by
keeping all the screws not too loose and not too tight.
If the collimation screw is a large screw
1. Using the 3mm Allen wrench, turn the large screw
clockwise a small amount, no more than 1/4 of a turn
(Figure 4a).
2. ow, with the 2mm Allen wrench turn the two adjacent small
screws (Figure 4b) counterclockwise no more than 1/4
turn.
3. Locate the small screw that is 180° opposite the rst screw
(Figure 4c) and turn it clockwise no more than 1/4 turn.
4. Turn the two large screws adjacent to the small screw
(Figure 4d) counterclockwise no more than 1/4 turn.
5. Repeat the above steps until the black crescent shrinks
in size and nally disappears.You will need to repeat this
procedure (or the small screw procedure below) starting
with a different screw if the black crescent appears in a
location other than at the bottom of the eld of view as in
this example.
If the collimation screw is a small screw
Follow these steps if the screw closest to the direction of the
black crescent is a small collimation screw. It’s basically the
same as the above procedure except that you start with a small
screw, then adjust the two adjacent large screws, etc.
1. Using the 2mm Allen wrench, turn the small screw
counterclockwise a small amount, no more than 1/4 turn.
2. Now, with the 3mm Allen wrench, turn the two adjacent
large screws clockwise no more than 1/4 turn.
3. Locate the large screw that is 180° opposite the rst screw
and turn it counterclockwise no more than 1/4 turn.
4. Turn the two small screws adjacent to the large screw
clockwise no more than 1/4 turn.
5. Repeat the above steps until the large black crescent
shrinks in size and nally disappears.You will need to
repeat this procedure (or the large screw procedure above)
starting with a different screw if the large black crescent
appears in a location other than at the bottom of the eld
of view as in this example.
Once this collimation procedure has been successfully complet-
ed, a star test should show concentric rings with the dark sec-
ondary mirror shadow perfectly centered, as in Figure 1(right
side).
B. Collimating the Orion 150mm and 180mm
Maksutov-Cassegrains
Follow this procedure for Maksutov-Cassegrains having three
close pairs of collimation screws on the rear cell. Figure 2b
shows the back of the 180mm Maksutov-Cassegrain. You will
need a 4mm and a 2.5mm Allen wrench to turn these screws.
Remove the diagonal and eyepiece and look into rear opening
of the tube (also remove the dust cover from the front of the
tube!). This should be done indoors, with the telescope pointed
at a light-colored wall in a well-lit room. Try to keep your eye
centered with respect to the rear opening of the tube as best as
possible. Using an Orion Collimating Eyepiece or a Cheshire
Front of
telescope
Secondary
mirror
Secondary
reflection of
inside
of tube
Reflection of
your eye in
secondary
mirror
Black crescent =
reflection of inside of
tube (misalignment)
Reflection of
your eye in
secondary
mirror
Secondary
mirror
Front of
telescope
Figure 3. a) If the telescope’s optics are out of alignment the view
through the rear opening of the telescope will resemble this. b) With
the optics properly aligned the view through the rear opening of the
telescope will look like this.
c) Turn the small screw that is 180° opposite the first screw
clockwise no more than 1/4 turn. d) Turn the two large screws
adjacent to the small screw counterclockwise no more than 1/4
turn.
a) Using the 3mm Allen wrench, turn the large screw clockwise a
small amount, no more than 1/4 of a turn. (Note, actual selected
alignment screw will vary.) b) Now, with the 2mm Allen wrench,
turn the two adjacent small screws counterclockwise no more
than 1/4 turn.
a b
Figure 4. Collimation Sequence
a
c
b
d
3

eyepiece will aid greatly in keeping your eye centered and is
strongly recommended.
If your telescope is out of collimation, the view will resemble
Figure 3a; if it is properly collimated the view will resemble
Figure 3b. The direction of the misalignment in your telescope
may differ from Figure 3a, but the diagram will give you the
general idea of how things will look.
In Figure 3a, note the black crescent at the outer edge of the
eld of view. The appearance of such a black crescent indicates
that the telescope is out of alignment. Note which way the front
of the telescope would need to move in order to “ll” that black
crescent and resemble Figure 3b. Then locate the pair of col-
limation screws on the back of the scope that is closest to the
direction that the front of the telescope needs to move. So for
instance, if the black crescent you see is like that pictured in
Figure 3a – on the bottom – then you would start with the pair
of screws closest to the bottom, as in Figure 5.
Each pair of screws acts independently from the other pairs. So
for instance, you may only need to adjust one pair of screws to
bring the primary mirror into proper collimation. On the other
hand, you may nd you need to adjust two pairs or all three
pairs.
1. For this example, starting with the bottom-most pair of
collimation screws, rst tighten (turn clockwise) the large
screw in the pair by no more than 1/4 turn, then loosen
(turn counterclockwise) the adjacent small screw by no
more than 1/4 turn.
2. Then look into the rear opening of the tube and determine
if the black crescent has reduced in size, increased in size,
or been completely “lled”, i.e., disappeared. If the crescent
has reduced in size, continue
adjusting the same pair of
collimation screws in the same
manner – tightening the large
screw by a small amount and
loosening the small screw by
the same amount – until the
crescent has been completely
“lled.”
3. If the crescent has increased
in size, the optics have been
moved further out of alignment.
To correct this, reverse what
you did in step 1 by tightening
the small screw and loosening
the large one in the pair by
up to 1/4 turn, to undo the
previous adjustment. Then adjust one or both of the other
two pairs of collimation screws to try to shrink the black
crescent until it disappears.
You will need to repeat this procedure starting with a different
pair of collimation screws if the black crescent appears in a loca-
tion other than near the bottom of the eld of view as in this
example.
It will take some trial and error to get a feel for which screw pairs
to adjust and by how much in order to nail the perfect collima-
tion! But keep at it and you will eventually succeed.
Again, collimation should only be attempted if you have
confirmed the telescope is actually out of collimation after
performing a star test!
Figure 5. If the view
inside the tube shows
the black crescent at the
bottom, as in Figure 3a,
then the first adjustment
should be to the pair of
collimation screws closest
to that direction, as
indicated here.
Corporate Offices: 89 Hangar Way, Watsonville CA 95076 - USA
Toll Free USA & Canada: [phone]
International: [phone]
Customer Support: [email protected]
Copyright © 2020 Orion Telescopes & Binoculars.All Rights Reserved. No part of this product
instruction or any of its contents may be reproduced, copied, modied or adapted, without the
prior written consent of Orion Telescopes & Binoculars.
AN EMPLOYEE-OWNED COMPANY
One-Year Limited Warranty
This Orion product is warranted against defects in materials or workmanship for a period of one year from the date
of purchase. This warranty is for the benet of the original retail purchaser only. During this warranty period Orion
Telescopes & Binoculars will repair or replace, at Orion’s option, any warranted instrument that proves to be defective,
provided it is returned postage paid. Proof of purchase (such as a copy of the original receipt) is required. This war-
ranty is only valid in the country of purchase.
This warranty does not apply if, in Orion’s judgment, the instrument has been abused, mishandled, or modied, nor
does it apply to normal wear and tear. This warranty gives you specic legal rights. It is not intended to remove or
restrict your other legal rights under applicable local consumer law; your state or national statutory consumer rights
governing the sale of consumer goods remain fully applicable.
For further warranty information, please visit www.OrionTelescopes.com/warranty.
4