Orion 7220 User manual

Orion 70mm Multi-Use
Finder Scope
#7220
INSTRUCTION MANUAL
Providing Exceptional Consumer Optical Products Since 1975
IN 497 Rev. C 06/14
Customer Support:
www.OrionTelescopes.com/contactus
Corporate Offices:
89 Hangar Way, Watsonville CA 95076 - USA
Copyright © 2012-2014 Orion Telescopes & Binoculars
All Rights Reserved. No part of this product instruction or any of its
contents may be reproduced, copied, modified or adapted, without the
prior written consent of Orion Telescopes & Binoculars.

2
Congratulations on your purchase
of the Orion 70mm Multi-Use Finder
Scope (MF70).
The finder scope is an invaluable tool
for finding objects in the night sky. It is
a miniature telescope that mounts onto
a larger telescope. Because of its low
magnification and wide field of view,
it is much easier to first locate and
center an object in the finder scope
before subsequent viewing through the
main telescope. To properly install and
use your finder scope, please read this
instruction manual.
70mm Multi-Use Finder Scope (MF70)
The MF70 is a large aperture finder scope. Its large 70mm aperture captures
twice the amount of light than a conventional 50mm finder scope.
The light gathering power can be calculated as follows:
Divide the telescope aperture (in mm) by 7mm (dilated pupil diameter of a
young person) and squaring the result.
50mm Finder Scope = (50/7)² = 51x
70mm Multi Finder = (70/7)² = 100x
Hence the MF70 captures twice the amount of light than a conventional 50mm
finder scope
Figure 1. The Orion 70mm Multi-Finder (MF70).
Figure 2. Field of view (FOV) using
the MF70 with a 15mm Eyepiece
(approximately 4 degrees FOV).

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With its fast focal ratio (f/4) the MF70
can be used as a wide field of view
(FOV) telescope or as a very bright
finder scope or guide scope.
Field of View (FOV)
It is important to understand that a
wide field of view is what makes a
finder scope a special tool. It allows
viewing a vast portion of the skies with
low magnification.
Use a low power eyepiece to get the
best FOV with the Multi-Finder. We
recommend an eyepiece focal length
of 15mm. This will give about 18x
power which is good for resolving faint
stars and even to observe some deep
sky objects.
Reaching Focus With the 70m Multi-Finder
The MF70 has a very limited focus range of approximately 0->15mm. Some eye-
piece and diagonal combinations may not come to focus.
The light path distance of the MF70 is approximately 80mm therefore you will
need to select an accessory and diagonal combination that is within this required
spacing distance in order to achieve focus.
Generally the rule is: if focus cannot be reached with a particular combination of
eyepiece and diagonal then it is recommended to change the diagonal for a 90
degree prism diagonal which requires much less focus travel than other diago-
nals (Figure 3 & 4). The eyepiece may also be exchanged for one with a smaller
focus travel requirement (Figure 5).
When used as a finder scope we recommend using a 90 degree prism diagonal
with eyepieces. When used as a guide scope we recommend using a 90 degree
Figure 3. If more in-focus travel is required a 90 degree Prism Diagonal may be required.
A 45 degree Prism Diagonal requires more in-focus than any other diagonal.
Figure 4. Example diagonal types and
their associated focus travel distance.
Diagonal Focus Distance Chart
Brand/Type
Focus
Distance
(mm)
Orion 90 degree prism 74
Orion 90 degree mirror 94
Orion 45 degree prism 102
Vixen 1.25” Prism 63
Takahashi 1.25” Prism 64
Baader T2 Prism (Zeis) 67
Celestron 1.25” Prism 67
Vernonscope 1.25” Silver mirror 73
Teleview 1.25” Everbrite Dielectric 78
Astro-Tech 1.25” Dielectric 94

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mirror diagonal with guide camera.
When used as a terrestrial spotting
scope for near objects we recommend
using a 45 degree prism diagonal.
Getting Started
The MF70 comes fully assembled.
You only need to use a standard 1.25”
diagonal prism/mirror (not supplied)
and a standard 1.25” low power eye-
piece (not supplied) to start using it.
The MF70 can also be used in several
configurations.
Start by installing the MF70 into
the dovetail base of your telescope
(Figure 6). Tighten the dovetail base
thumbscrew in order to securely attach
the MF70 to your telescope.
Insert the diagonal prism/mirror into
the helical focuser (Figure 7). Use the
eyepiece thumbscrew to secure the
diagonal.
You are now ready to choose from
a variety of accessories such as
eyepieces and reticle eyepiece for
visual or photography work, or a guide
camera such as the Orion StarShoot
AutoGuider for guiding.
Focusing the Finder Scope
Loosen the rotation locking thumb-
screw so that the helical focuser can
rotate to adjust focus.
Loosen the eyepiece thumb screw
and hold the diagonal (with eyepiece)
with one hand to keep the diagonal in
place against the helical focuser. Since
adjusting focus rotates the helical
focus, the diagonal too would rotate if
it was locked down with the eyepiece
thumbscrew.
With the other hand rotate the helical focuser until focus is reached. Using one of
the included spacers provides a nice grip to turn the helical focuser or the eye-
Figure 5. Example eyepiece types and
their associated focus travel distance.
Eyepiece Focus Distance Chart
Brand Model
Focal
Length
(mm)
Focus
Distance
(mm)
Orion Ultrascopic 35 -12
Orion Sirius Plossl 32 21
Orion Sirius Plossl 20 0
Orion Sirius Plossl 10 0
Explore
Scientific 82 Degree 4.7 6
Celestron Plossl 9 -8
Meade SWA 16 5
Meade SWA 24 3 1/2
Baader Hyperion 31 -17
Pentax XO 5.1 -0
Pentax XW 20 -0
Pentax XW 10 0
Pentax XW 5 0
Pentax XW 3.5 0
Takahashi LE 12.5 -0
Takahashi LE 30 -3
Takahashi LE 7.5 0
Takahashi LE 5 1/2
William
Optics UWAN 16 2 1/2
Tele Vue Ethos 8 -5 1/2
Tele Vue Plossl 40 12
Tele Vue Plossl 32 4 1/2
Tele Vue Plossl 32 4 1/2
Tele Vue Panoptic 24 5 1/2
Tele Vue Panoptic 19 5 1/2
Tele Vue Plossl 15 6
Tele Vue Plossl 11 6

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piece thumbscrew itself can be used
as a lever to adjust focus.
When focused is reached lock down
the eyepiece thumbscrew. Tiny adjust-
ments can be made before finally lock-
ing down the rotation locking thumb-
screw to lock the focuser position. The
thumbscrew should only be slightly
tightened to avoid damage to the inter-
nal threads.
Use the Multi-Finder As a
Large Aperture Guide Scope
Small aperture finder scopes offer
low weight and a low cost solution for
guiding with a guide camera. They are
however limited by the light gathering
capability.
The MF70 boasts a huge 70mm aper-
ture. This will have a dramatic effect on
the amount of stars seen by the guide
camera, and increases the chance to
get a suitable bright star for guiding.
Due to its large aperture, light weight
design and ability to be accurately
centered, the MF70 makes an excel-
lent guide scope.
Cameras normally have a very small
back focus requirement and therefore
a long extension/spacer or mirror
diagonal should be used in order to
reach focus.
This same setup will also work with
CCD cameras to turn your MF70 into
a wide field astrograph.
Use the Multi-Finder As a Small
Astrograph
At f/4 the MF70 provides very bright
images. Use a dedicated astrophotography camera, such as the StarShoot G3
camera, with the MF70 to get deep sky images of wide nebulosity or star field of
the Milky Way.
Figure 6. Installing the MF70 in the
Dovetail Base.
Figure 7. Multi-Finder with a low power
Eyepiece.
Figure 8. Multi-Finder with a reticle
eyepiece for precise centering.

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The MF70 can even be used with a
DSLR camera by using the T-threads
on the MF70 to attach the camera
(Figure 10).
The light path distance of the MF70
is approximately 80mm so you need
to calculate the required spacing dis-
tance in order to achieve focus with
the camera.
For a DSLR camera, with T-thread
adapter, a 25mm spacer is required
(not included).
We recommend using the #05528
Orion T-thread Spacing Ring Kit or
the #05326 Orion Variable 12-17mm
T-thread Spacer Ring to get the best
spacing combination.
For the StarShoot AutoGuider or the
StarShoot G3, the required spacing
is approximately 70mm. This can be
accomplished by using the camera
with a mirror diagonal.
How to Use the Provided
Spacers (7mm & 15mm)
The spacers are used to add addi-
tional spacing. This might be neces-
sary for certain mirror diagonals that
require the focuser to be too far out.
Adding the spacer provides more sta-
bility to the mechanism (Figure 11).
The spacers may also help to provide
a grip to adjust the helical focuser.
Remove the eyepiece thumbscrew
from the focusing tube (Figure 12).
Thread the spacer to the focusers
T-threads and re-insert the eyepiece
thumbscrew (Figure 13)
Lock the spacer with the locking
thumbscrew (Figure 14). This prevents the spacer from getting loose. If required,
combine the two extenders to reach maximum spacing of 22mm.
Figure 9. MF70 with StarShoot
AutoGuider guide camera.
Figure 10. Small Astrograph use with a
DSLR (for full frame cameras there may be
some vignetting on the frame edge).
Figure 11. MF70 with 15mm spacer
added.

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We recommend using the #05528
Orion T-thread Spacing Ring Kit or
the #05326 Orion Variable 12-17mm
T-thread Spacer Ring to reach other
additional spacing combinations.
Weight Balance
The MF70 was designed to be
extremely light weight. By adding an
optional prism/mirror diagonal and
eyepiece, the total weight can increase
rapidly. Adjust your telescope rings to
balance the telescope.
For Dobsonian telescopes you might
need to add some counterweight to
the back of the telescope to get per-
fect balance.
Adjusting the Aim of the MF70
Now that you have your installed the
MF70 and chosen one of the configu-
rations that best suits your observing
needs, it is time to adjust the aim of
your MF70.
The finder scope has a wide field of
view to facilitate the location of objects
for subsequent viewing through the
main telescope, which has a much
narrower field of view.
The finder scope and the main tele-
scope must be aligned so they point
to exactly the same spot in the sky.
Alignment is easiest to do in daylight
hours.
First, insert an eyepiece into the main
telescope and point the telescope at
an object such as the top of a tele-
phone pole or a street sign that is at
least a quarter-mile away.
Move the telescope so the target object appears in the very center of the field of
view when you look into the eyepiece.
Now look through the MF70. Is the object centered in the finder scope’s field
of view? If not, hopefully it will be visible somewhere in the field of view (FOV),
Figure 12. Removing the thumbscrew.
Figure 13. Re-inserting the thumbscrew.
Figure 14. Secure the spacer with the
locking thumbscrew.

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so that only fine adjustment of the MF70’s adjustment screws will be needed to
center it on the FOV. Otherwise you’ll have to make coarser adjustments to the
MF70’s adjustment screws to redirect the aim of the MF70.
The best method for adjusting the aim is to loosen one of the adjustment screws
while tightening another adjustment screw.
Once the target object is centered in the FOV of the Multi-Finder, look again
in the telescope’s eyepiece and see if it is still centered there as well. If it isn’t,
repeat the entire process, making sure not to move the telescope while adjusting
the alignment of the finder scope.
When the target object is centered on the FOV of the MF70 and in the tele-
scope’s eyepiece, the MF70 is aligned and ready to be used for locating objects.
Make sure all the adjustment screws are now locked down tightly so that the
MF70’s aim will stay the same as the telescope moves from target to target.
The Multi-Finder alignment should be checked before every observing session.
This can easily be done at night, before viewing through the telescope. Choose
any bright star or planet, center the object in the telescope eyepiece, and then
adjust the bracket’s adjustment screws until the star or planet is also centered in
the MF70’s FOV.
The MF70 and bracket can be removed from the dovetail base for storage, and
then reinstalled without significantly changing the Multi-Finder’s alignment.
Warning: Never look directly at the Sun with the naked eye or with a telescope
– unless you have a proper solar filter installed over the front of the telescope!
Otherwise, permanent, irreversible eye damage may result.
Caring for the Finder Scope
If you give your Multi-Finder reasonable care, it will last a lifetime. Keep the dust
cap on the finder when it is not in use. If you plan to move your telescope any
significant distance, you should remove the Multi-Finder and bracket in order to
prevent them from getting bumped. You can store the Multi-Finder in any small
padded case to protect it from damage.
Cleaning Lenses
Any quality optical lens cleaning tissue and optical lens cleaning fluid specifically
designed for multi-coated optics can be used to clean the exposed lenses of
your finder scope. Never use regular glass cleaner or cleaning fluid designed for
eyeglasses. Before cleaning with fluid and tissue, blow any loose particles off the
lens with a blower bulb or compressed air. Then apply some cleaning fluid to a
tissue, never directly on the optics. Wipe the lens gently in a circular motion, then
remove any excess fluid with a fresh lens tissue. Oily fingerprints and smudges
may be removed using this method. Use caution; rubbing too hard may scratch
the lens. For larger lenses, clean only a small area at a time.

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Specifications
Optical design Refractor
Optical diameter 70mm
Focal length 279mm
Focal ratio f/4.0
Coatings Fully coated
Glass material Crown/Flint
Resolving power 1.70arc*sec
Lowest useful magnification 10x
Mount type Optical Tube without Mount
Tube material Aluminum
Length of optical tube 8.2 in.
Weight, optical tube 1.2 lbs.
Warranty One year
WARNING: Never look directly at the Sun with the naked eye or with
a telescope – unless you have a proper solar filter installed over the
front of the telescope! Otherwise, permanent, irreversible eye damage
may result.

10
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 benefit 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 warranty 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 modified, nor does it apply to normal wear and tear. This warranty gives
you specific 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.
Orion Telescopes & Binoculars
Corporate Offices: 89 Hangar Way, Watsonville CA 95076 - USA
Customer Support: www.OrionTelescopes.com/contactus
Copyright © 2012-2014 Orion Telescopes & Binoculars
All Rights Reserved. No part of this product instruction or any of its contents may
be reproduced, copied, modified or adapted, without the prior written consent of
Orion Telescopes & Binoculars.