Zhumell Dobsonian User manual

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OWNER’S MANUAL
DOBSONIAN TELESCOPE
ZHUMELL Z8 DELUXE DOBSONIAN REFLECTOR TELESCOPE

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Zhumell customers know that there are plenty of ways
to experience the world. They also understand that,
however you choose to explore it, the best experience is one
that fully immerses you in the world’s most striking details.
That’s where our optics products come in. We strive to put
high-performance products in the hands of our customers
so that they can experience the world up close, with their
own eyes.
With Zhumell, you get field-tested, precision-crafted optics at
the best possible value. So even if you’re just starting out as
an amateur birder or astronomer, you don’t have to settle for
entry-level products. Zhumell customers enjoy life’s pursuits,
hobbies, and adventures in rich, colorful detail- the kind of
detail that only high-performance optics can produce.
At Zhumell, we design our binoculars, telescopes, and
spotting scopes for discerning, price-conscious users
who are uncompromising on quality. If you’re looking for
accessibly priced optics that will bring your world within
reach, you’re looking for Zhumell.
Enjoy the dob.

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ENJOYING YOUR
ZHUMELL DOBSONIAN TELESCOPE
i. Warnings
ii. Cleaning and Maintenance
iii. Collimation
1. Caring For Your Telescope
2. Specifications
3. Parts List
4. Telescope Assembly
5. Donsonian Telescope Basics
6. Viewing Through Your Telescope
7. Observation Tips
8. Cool Views
9. Astronomy Formulas
10. Astronomy Terminology
11. Telescope Terminology
12. FAQs
13. Warranty
i. Base Assembly
ii. Optical Tube Assembly
i. 1.25-inch Eyepieces
ii. 2-inch Eyepieces
iii. Altitude and Azimuth
iv. Focusing the Image
v. Cooling Fan
vi. Transportation
i. Checking and Aligning Your Finderscope
i. Selecting a Viewing Site
ii. Cooling Your Telescope
iii. Seeing and Transparency
iv. Dark-Adapting
v. Tracking Celestial Objects
vi. Selecting an Eyepiece
i. The Moon
ii. The Planets
iii. The Stars
iv. Deep-Sky Objects
v. Starhopping

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Zhumell telescopes are precision astronomical instruments designed
for ease of use and versatility in their application. As with any
telescope, Zhumell telescopes require some technical knowledge
of stellar movement and optical properties. We have provided basic
instructions for telescope use and astronomical viewing in this manual.
Your Zhumell Dobsonian Telescope is built with the highest-quality
optics and top-notch construction to provide years of reliable
functionality, but will require proper care.
If, after reading this manual, you still have questions about your
Zhumell telescope, please visit http://www.zhumell.com for
more helpful tips and contact information. Our customer service
representatives are available to address any problems you encounter
with your telescope. Please let us know about your experiences;
we would like to hear your feedback.
Enjoy your Zhumell.
CARING FOR YOUR
ZHUMELL DOBSONIAN TELESCOPE

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WARNINGS
• Do not use telescope or finderscope to look at the sun without
an appropriate solar filter. Doing so will cause permanent and
irreversible eye damage.
• Never use an eyepiece filter as a solar filter. Only solar filters will
completely cover the opening of the optical tube and provide
proper eye protection.
• Make sure no screws are loose before using telescope.
• Do not drop or shake your telescope as doing so may damage
the optics, or harm you or the people around you.
CARING FOR YOUR
ZHUMELL DOBSONIAN TELESCOPE

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COLLIMATION
Periodically, you will find that it is necessary to align the optical
components of your telescope. This procedure is called collimation.
There is no collimator included with the Zhumell Dobsonian, but regular
collimation is recommended for optimum telescope usage.
1. Remove the eyepiece from the eyepiece holder and insert laser
collimator into eyepiece holder. Secure the laser collimator by
tightening thumbscrew.
2. Turn the thumbscrew located on the side of the collimator to turn on
the collimator.
3. Look through the hole in the side of collimator to see where the laser
is reflected onto the reticle. If you cannot see the laser reflected back
onto the reticle, align the secondary mirror by adjusting the secondary
mirror collimation screws until the laser is reflected onto the inside of
the collimator.
4. Loosen 3 locking screws on bottom of optical tube (the thin ones that
stick farther out from the back of the mirror).
5. Align the laser to the center of the reticle by adjusting the 3 primary
mirror adjustment screws (the thick screws in the back of the mirror).
Do not over-turn these screws (max of ¼ turn at a time).
6. Tighten the 3 locking screws on bottom of optical tube to lock the
primary mirror into place.
USING YOUR
ZHUMELL DOBSONIAN TELESCOPE

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USING YOUR
ZHUMELL DOBSONIAN TELESCOPE
CLEANING AND MAINTENANCE
A telescope is carefully aligned during construction, and great care should
be taken to maintain this alignment over the life of the telescope. Cleaning
should be done as little as possible and then only with mild soap solution
and a soft, lint-free cloth. Do not rub elements when cleaning. Blot optical
components gently and allow telescope to air-dry. Store telescope in
its box or in a telescope case when not in use. Do not use pure alcohol
or solvents to clean any parts of the telescope. Do not remove optical
elements from the telescope as doing so may affect the alignment of
optical components when reassembled. If telescope needs realignment,
contact Zhumell or another professional.
1. Brush telescope optics with camelhair brush or blow off dust with
an ear syringe (can be purchased at any pharmacy). Do not use a
commercial photographic lens cleaner.
2. Remove organic materials (e.g. fingerprints) with short gentle strokes
using soft white tissue paper and a solution of three parts distilled
water and one part isopropyl alcohol. You may also add one drop of
biodegradable dish soap to one pint of the homemade solution. Do
not use lotioned or scented tissues as they could damage the optics
of your telescope.
3. Wipe down the outside of your telescope with a dry cloth to remove
condensation prior to packing up your telescope. Do not wipe any of
the optical surfaces. Instead, allow the optics to dry naturally in warm
indoor air prior to packing up your telescope.
4. Protect your telescope from excessive heat. For example, do not
store your telescope in a sealed car on a warm day. Excessive storage
temperatures can damage your telescope.

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SPECIFICATIONS FOR YOUR
ZHUMELL DOBSONIAN TELESCOPE
Zhumell Z8
Objective/Aperture 203 mm / 8 inches
Focal Length 1200
Limiting Magnitude 14.04
Focal Ratio F/5.91
OPTICAL TUBE ASSEMBLY
Eyepiece Format: 1.25 inch, and 2 inch
Finderscope: 8x50
Mount Type: Dobsonian
Tube Mount: Cradle Mount
Mount Adjustment: Altitude-Azimuth
Materials: Wood, Melamine
Box 1 of 2
• Dobsonian optical tube
• Plastic tube cover
• 2 silver side bearings
• Battery pack for cooling fan
• Newtonian collimator
• 32 mm eyepiece (2 inch format)
• 9 mm eyepiece (1.25 inch format)
• Moon filter (1.25 inch format)
Box 2 of 2
• 8x50 finderscope
• Handle
• 10 long black Allen screws
• 2 medium silver Allen screws
• 3 medium silver Phillips screws
• Allen wrench
• 3 black plastic feet
• 2 short black Phillips screws
• Eyepiece holder shelf
• 2 large round black wood base plates
• Lazy susan (2 metal discs with a black
plastic roller in the middle)
• One black knob, with a thick screw, spacer,
large washer, small ball bearing washer, and
small plain washer
• 2 large black wood side panels for the base
• 1 small black wood side panel for the base
Not Included
• Philips Screwdriver
• AA Batteries
All Holes have been predrilled
PARTS LIST

ASSEMBLY OF YOUR
ZHUMELL DOBSONIAN TELESCOPE
a. Base Sides (2)
b. Base Front
c. Base Plates (2)
d. Bearing Plates (3)
e. Handle (and (2) silver
Allen screws)
f. Eyepiece Tray (and (2) black
Philips screws)
g. Feet (3)
h. Long Black Allen Screws (10)
i. Allen Wrench
j. Adjustment Bolt (with (2)
washers, (1) ball bearing, and
(1) Axle Sleeve)
Unbox and gather the pieces for base assembly. You will need:
c
a
b
efhj
g
d
Zhumell Z8
Objective/Aperture 203 mm / 8 inches
Focal Length 1200
Limiting Magnitude 14.04
Focal Ratio F/5.91
All Holes have been predrilled

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BASE ASSEMBLY
STEP 1: Screw the handle onto the Base Front using the (2) pre-drilled holes on the
front. Make sure that it is secure.
STEP 3: Repeat with the Right Base Side to complete the box. Be sure that all three sides are firmly
attached and feel stable.
STEP 2: Connect the Base Front to the Left Base Side using the pre-drilled holes in the Base Front and
(2) Long Black Allen Screws
1
ASSEMBLY OF YOUR
ZHUMELL DOBSONIAN TELESCOPE
First, you will be assembling the telescope base housing. This will be the structure that holds your
scope in place.

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STEP 4: To attach the Eyepiece Tray to the Right Base, it’s easiest to turn the assembly on its side. Attach
the tray using the (2) pre-drilled holes and (2) black Philips screws. Return the base to standing position and
make sure the tray is secure.
YOU ARE NOW READY TO BEGIN THE ASSEMBLY OF THE BASE PLATE. THIS WILL BE THE PART THAT
ALLOWS YOUR BASE HOUSING AND TELESCOPE TO ROTATE IN A “LAZY SUSAN” STYLE.
STEP 5: First, the feet must be attached to the Base Plate. Choose the Base Plate with (1) center hole and
(3) holes around the edge. IMPORTANT: The feet must be attached to the side with a brass center hole.
Screw all (3) feet in place, with the wider side facing the board, using (3) medium silver Philips screws.
STEP 6: Choose the Base Plate with (1) center hole and (6) holes around the edge. Flip the base housing
upside-down and align the six pre-drilled holes with the base plate.
ASSEMBLY OF YOUR
ZHUMELL DOBSONIAN TELESCOPE

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STEP 7: Be sure the side with recessed holes is facing away from the base housing. Screw (6) long black
Allen screws into these holes until they are flush with the surface.
STEP 8: To assemble the Adjustment Bolt, hold the parts in your hand in this order: Small Washer; Ball
Bearing; Large Washer. Place them on the threaded bolt in that order, with the small washer closest to the
plastic knob.
STEP 9: Place the Base Plate with feet on level ground, feet facing downward. Insert the Axle Sleeve into
the center hole.
ASSEMBLY OF YOUR
ZHUMELL DOBSONIAN TELESCOPE

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STEP 10: Arrange the Bearing Plates with the “wagon wheel” plate sandwiched between the two light blue plates.
Place this whole assembly onto the Axle Sleeve centered on the Base Plate. Check that it rotates smoothly.
STEP 11: Pick up the Base Plate and Base Housing assembly and place it on top of the Base Plate and Bearing
Plate Assembly, aligning the center hole with the Axle Sleeve. The top assembly should now rotate freely over the
bottom Base Plate.
STEP 12: Screw the Adjustment Bolt (with washers and ball bearing) into the Axle Sleeve, through all of the
assembled base parts. This will be your means to rotate and secure your Dobsonian.
ASSEMBLY OF YOUR
ZHUMELL DOBSONIAN TELESCOPE

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ASSEMBLY OF YOUR
ZHUMELL DOBSONIAN TELESCOPE
OPTICAL TUBE ASSEMBLY
2
Unbox and gather the pieces for the Optical Tube Assembly. These are -
a. Dobsonian Optical Tube
b. Finderscope
c. Silver Side Bearings (2)
d. Laser Collimator
e. Battery Pack for Cooling Fan
f. 1.25-inch 9mm Plossl Eyepiece
g. 2-inch 30mm Plossl Eyepiece
h. 1.25-inch Moon Filter.
STEP 1: Remove the (2) bolts found on the opening on one side of the OTA. This is where you will
connect the silver Side Bearing. Align the bearing (top bolt first) and tighten into place. Repeat on the other
side of the OTA.
c
a
be
fh
g
d

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ASSEMBLY OF YOUR
ZHUMELL DOBSONIAN TELESCOPE
STEP 2: You are now ready to place the OTA onto the Base Assembly. Be sure to have the base
assembly ready to align with the OTA before you lift the optical tube. The indentations on the Base
Assembly will perfectly fit the silver Side Bearings on the OTA.
STEP 3: Locate the Finderscope Bracket on the OTA. Loosen the thumbscrew on the bracket with your
fingers and slide the Finderscope into place. Tighten the screw so that the Finderscope is secure.
You are now ready to insert an eyepiece and begin using your Zhumell Dobsonian
telescope. Continue reading for instructions and viewing tips.
STEP 1: Remove the (2) bolts found on the opening on one side of the OTA. This is where you will
connect the silver Side Bearing. Align the bearing (top bolt first) and tighten into place. Repeat on the other
side of the OTA.

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USING 1.25-INCH EYEPIECES
BASICS FOR YOUR
ZHUMELL DOBSONIAN TELESCOPE
1. The 1.25-inch is the most commonly used eyepiece format. The
measurement of 1.25 inches is the diameter of the eyepiece tube,
measured on the chrome side.
2. The eyepiece holder and Crayford focuser come already attached to the
optical tube, next to where the finderscope is mounted.
3. Remove the plastic dust cover from the eyepiece holder.
4. Loosen the silver thumbscrew closest to the eyepiece hole. (It is part of
the 1.25-inch adapter. More on this adapter in the 2 - inch
eyepiece section.)
5. Take out your 1.25-inch eyepiece. Remove the plastic covers and pull
up the rubber to use the eyecup.
6. Slide the chrome end of the eyepiece into the eyepiece holder.
7. View through the eyepiece and focus as needed. (See focusing section.)
8. To remove the eyepiece, loosen the silver thumbscrew.
9. Pull out the eyepiece from the holder.
10. Use the plastic dust covers to protect the eyepiece and focuser
during storage.

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BASICS FOR YOUR
ZHUMELL DOBSONIAN TELESCOPE
USING 2-INCH EYEPIECES
1. The 2-inch eyepiece format is the largest. 2 inches is the diameter of the
eyepiece tube, measured on the chrome side.
2. Loosen the silver thumb screw underneath the eyepiece opening.
3. Pull the adapter out of the focuser.
4. Take out your 2-inch eyepiece. Remove the plastic covers.
5. Slide the chrome end of the eyepiece into the focuser.
6. Tighten the bottom thumbscrew to hold eyepiece in place.
7. View and focus as desired.
8. To remove, loosen the thumbscrew and pull the eyepiece out of the focuser.
9. For storage, replace the adapter with the dust cover.

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ALTITUDE AND AZIMUTH
1. Your Zhumell Dobsonian is adjustable along two axes - altitude (up/
down) and azimuth (left/right). Adjustments to the telescope’s position
can be made along one or both axes at the same time.
2. Gently take hold of the end of the OTA and move it either left or right (it
will spin about its central azimuth bolt) or up and down (it will rotate on
the Side Bearings on the OTA).
3. The telescope can be positioned to view anywhere in the night sky, but
be sure to let it move naturally - never force your telescope to move.
BASICS FOR YOUR
ZHUMELL DOBSONIAN TELESCOPE
FOCUSING THE IMAGE
1. With an eyepiece in the focuser, loosen both back thumbscrews on the
left side on focuser.
2. Push or pull the focuser gently until image becomes as clear as possible.
3. Alternatively, turn the large, up-down, rack-and-pinion knobs to adjust
the focus. The black knob will adjust in smaller increments than the
large silver knobs.
4. The back thumbscrew will completely lock the focus. The front
thumbscrew will lock the push/pull ability, so that only the
rack-and-pinion knobs can be used to adjust focus.
5. Tighten both knobs to completely lock the focuser.

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BASICS FOR YOUR
ZHUMELL DOBSONIAN TELESCOPE
TRANSPORTATION
1. IMPORTANT - never try and transport both the base and OTA as a
single unit. Gently lift the OTA off the base and secure in a telescope
case for transportation. Move the base separately, as a single unit,
and handle with care.
2. If you do not have a case for your Dobsonian, let common sense
dictate your transportation storage. It is vital that the OTA does not
roll or move around at all during travel, as this will affect the telescope
alignment. Pad and secure your telescope accordingly.

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VIEWING THROUGH YOUR
ZHUMELL DOBSONIAN TELESCOPE
Never look at the sun without using a solar filter. Do not use a regular
eyepiece as a solar filter. When using a solar filter, do not remove the
full lenscap, view only through the small opening. Looking at the sun
without proper use of a solar filter can cause permanent eye damage,
included blindness.
When viewing through the telescope, the image will appear to be
upside-down and inverted. This is normal and is a result of the optical
system design. It can be corrected by using an erecting prism when
viewing, but it is not necessary to do so.
Using your finderscope will help you locate celestial much more
quickly as the finderscope is equipped with a wider field of view than
your telescope. To simplify focusing while viewing, start with the lowest
power magnification and work up to the desired power.
When viewing faint deep-sky objects, images will not show color. The
human eye is not able to distinguish the differences in color found in
such dim images. The lack of color is due to human anatomy, not any
limitations of telescope construction.