Zhumell Tachyon 25x100 User manual

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OWNER’S MANUAL
ASTRONOMICAL BINOCULARS
ZHUMELL TACHYON 25X100 ASTRONOMY BINOCULARS

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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 view.

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ENJOYING YOUR
ZHUMELL ASTRONOMICAL BINOCULARS
1. Caring For Your Binoculars
2. Using Your Binoculars
3. Terrestrial and Astronomical Viewing
4. Astronomical Observation Tips
5. Cool Views
6. Astronomy Terminology
7. Warranty
i. Tripod Mounting
ii. Interpupillary Distance
iii. Center and Diopter Focus
i. Selecting a Viewing Site
ii. Seeing and Transparency
iii. Dark-Adapting
iv. Tracking Celestial Objects
i. The Moon
ii. The Planets
iii. The Stars
iv. Deep-Sky Objects
v. Starhopping

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Zhumell binoculars are precision optical instruments designed
for ease of use and versatility in their application. Your Zhumell
binoculars are 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 binoculars, 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 binoculars. Please let us know about
your experiences; we would like to hear your feedback.
Enjoy your Zhumell.
CARING FOR YOUR
ZHUMELL ASTRONOMICAL BINOCULARS

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WARNINGS
• Never look at the sun through your binoculars. Doing so can
cause permanent damage to your eyes, including blindness.
• Always be sure your binoculars are properly held, secured,
or stored.
• While viewing objects at distance, be sure to be aware of
what’s going on around you to prevent harm to yourself or
to your binoculars.
CARE
• When cleaning binocular lenses, use included lens cloth or other
soft, lint-free cloth.
• Use lens cleaner or diluted isopropyl alcohol to remove dirt and
smudges - other chemicals may damage your equipment. Always
apply solution to a lens cloth first, never directly to the lens.
• Store binoculars in a moisture-free area. Be sure to dry your
equipment before packing it up.
• Always use lens caps when binoculars are not in use.
• Always store your binoculars in a protective case to avoid
accidental damage.
CARING FOR YOUR
ZHUMELL ASTRONOMICAL BINOCULARS

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INTERPUPILLARY DISTANCE
Interpupillary distance is the distance between the eyepieces of a
binocular. Easy adjustment will ensure that your binoculars are giving
you the view you want. To adjust interpupillary distance, follow these
simple steps:
1. Hold binoculars in the normal viewing position
2. Grasp each barrel firmly
3. Gently move the barrels closer together or farther apart until you see
a single circular field
4. When your view appears as a single circle, the interpupillary distance
is correct. Note the settings for easy adjustment in the future.
To get the most from your Zhumell astronomical binoculars, be
sure to understand and properly use these features. Doing so will
lead to the most satisfying experience possible from your new
optical equipment.
TRIPOD MOUNTING
Zhumell astronomical binoculars are far too large to hold
comfortably in your hands while viewing. For most applications,
use the included tripod adapter as follows:
1. Slide the tripod adapter until the tripod base fits between the
binocular barrels
2. Securely tighten the tripod adapter
3. Screw a standard .25-inch #20 tripod base screw into the
threaded socket on the adapter
4. Adjust as needed
USING YOUR
ZHUMELL ASTRONOMICAL BINOCULARS

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EYEPIECE FOCUS
Your Zhumell binoculars have individual eyepiece focus, which allows
for greater control over your view. Each eyepiece is focused using
the diopter ring directly behind the lens. To bring your binoculars into
focus, follow these steps:
1. Choose a distant or astronomical object on which to focus.
2. Close your left eye or cover the left objective lens and turn the
right diopter until the object is in perfect focus.
3. Close your right eye or cover the right objective lens and turn the
left diopter until the object is in perfect focus.
4. When viewing with both eyes, the object should now be crystal-
clear. If it is not, make individual adjustments as needed.
USING YOUR
ZHUMELL ASTRONOMICAL BINOCULARS

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TERRESTRIAL AND ASTRONOMICAL VIEWING
Your Zhumell binoculars are equipped for both large-magnification
terrestrial viewing and astronomical viewing purposes. Although
they are light enough to hold in your hand, we recommend
these binoculars be mounted to a tripod for best results. At high
magnification, even the smallest movement of the binoculars
results in a large jolt to the view.
To use your binoculars for land-based viewing, mount to a tripod
and point the binoculars at the object you’d like to see. Adjust the
focus knobs to bring the object into clear view.
To use your binoculars for astronomical viewing, read the following
guide to achieve viewing success.
SELECTING A VIEWING SITE
The ideal site for using your binoculars for astronomical viewing
is in the middle of nowhere. Most users don’t have access to the
darkest of skies, however, so select a site that is both far from light
pollution and practical for travel. Avoid street lights, yard lighting,
rooftops, and chimneys, and never observe through an open
window indoors. Be sure your site is out-of-town or very dark and
has clear view of a large portion of the sky.

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ASTRONOMICAL OBSERVATION TIPS
SEEING AND TRANSPARENCY
Atmospheric conditions are of the utmost importance when
considering viewing conditions for your astronomical binoculars.
These conditions are commonly referred to as “seeing.” When seeing
is good, star twinkling is minimal and objects appear steady in your
lenses. Seeing is best overhead, worst at the horizon, and generally
better after midnight. You can’t see the stars without looking through
the atmosphere, so the clearer the air and the higher your altitude, the
better seeing conditions you will encounter.
A reliably quick way to judge seeing conditions is to look at bright stars
about 40° above the horizon. If the stars appear to twinkle, there is
significant atmospheric distortion and viewing at high magnification will
not be ideal. If these stars are steadily bright, chances of successful
viewing at high magnification are much better.
Judging the transparency of the air is also important in determining
viewing conditions. The best air is free of moisture, dust, and smoke,
which tend to scatter light, reducing a viewed object’s brightness.
How many stars can you see with your naked eye? If you are unable
to see stars of magnitude 3.5 or dimmer, transparency in your area is
poor. A good indicator star for this test is Megrez (mag. 3.4) - the star
in the Big Dipper connecting the handle to the dipper. If Megrez is not
visible, elements in the air will negatively affect your view.

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DARK-ADAPTING YOUR EYES
When you go out into the dark, your eyes need time to adjust. You
will initially be able to see only a fraction of the stars and objects your
eyes are capable of. Remain in the dark (don’t look at any lights or
cell phones) for at least 30 minutes, and your eyes should be around
80% of their full dark-adapted sensitivity. Every time bright light
comes into your eye, the dark-adapting process will start over.
When eyes are fully dark-adapted, you will probably still need to see
what you’re doing. Use a red-light flashlight to maneuver around the
area. A regular flashlight covered in red cellophane will work, but red
LED lights are best.
ASTRONOMICAL OBSERVATION TIPS
TRACKING CELESTIAL OBJECTS
The Earth is always rotating about its polar axis, completing one full
rotation every 24 hours. This is what defines our “day”, and we see it
in the apparent movement of sun and stars throughout each rotation.
In the same way that the sun rises and sets each day, the stars in
the sky rise and set each night. The motion translates to a rate of
approximately .25° per minute, or 15 arc-seconds per second.
This is commonly referred to as the sidereal rate.
As you observe any celestial object, remember that it is in motion. You
will need to continuously update your binocular position throughout a
viewing session, most easily done using your tripod adjustments.
As an object begins to leave your field of view, adjust your position in the
correct direction and bring the view back to center.

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ASTRONOMICAL OBSERVATION TIPS
Remember, your binoculars achieve a high level of magnification,
which shrinks your field of view accordingly. Objects will appear
to move faster at high magnification, and frequent positional
adjustments will need to be made.
THE MOON
The Earth’s moon is one of the easiest and most rewarding targets
at which to point your binoculars. Its rocky, cratered surface is close
enough to be rendered in some detail, and allows for satisfying
exploration. The best time for lunar viewing is during its partial
phases, when shadows fall on the craters and canyon walls to give
them definition. Even though the full moon may look like a
tempting target, the light is too bright and the definition too low for
optimal viewing.
THE PLANETS
The planets are beautiful and popular targets for astronomers, but
they can be more difficult to keep track of than the stars or moon.
Planetary position charts can readily be found online or in any
astronomical publication. Sun and Moon aside, the brightest objects
in the night sky are Venus, Mars, Jupiter, and Saturn. The apparent
size of planets can be quite small, but high-power binoculars provide
an adequately enjoyable view.
COOL VIEWS WITH YOUR
ZHUMELL ASTRONOMICAL BINOCULARS

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JUPITER
Jupiter is our solar system’s largest planet. Through your binocs,
you can easily see the planet and observe the changing positions
of its four largest moons: Io, Callisto, Europa, and Ganymede.
With the right conditions, you may be able to see cloud bands
wrapped around the planet and the famous Great Red Spot.
SATURN
This infamously ringed planet can be a fantastic sight through
your binoculars. The tilt-angle of the rings varies over a period
of many years, so they may be seen edge-on (like a thin line) or
broadside (like giant “ears” on each side of the planet). You will
need a good steady atmosphere to achieve a worthwhile view
of Saturn. If you look closely enough, you can see the Cassini
division - a thin, dark gap in the rings. You can also often make
out one or more of Saturns moons, including the largest - Titan.
VENUS
At its brightest, Venus is the most luminous of all the planets - so
bright that it is occasionally visible in full daylight. Venus appears
as only a thin crescent at its brightest, and it is never found far
from morning or evening horizon. No surface detail can be seen
on Venus as it is surrounded by dense cloud cover.
MARS
Mars makes a close approach to our planet once every two
years, which is the best time to observe it. With your binoculars,
you’ll be able to see a salmon-colored disk marked with dark
patches and possibly a whitish polar ice cap. Surface detail on
Mars is only observable during prime conditions with a high-
power magnification.
COOL VIEWS WITH YOUR
ZHUMELL ASTRONOMICAL BINOCULARS

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THE STARS
Through your binoculars, stars will appear much as they do to the
naked eye - as tiny points of light against a dark sky. Even powerful
binoculars cannot magnify stars to appear as anything more than
these pinpoints. You can, however, enjoy the different colors of their
glow and locate many beautiful double- and multiple-stars.
Two popular targets are the “Double-Double” in the constellation Lyra
and the two-color double star Albireo in Cygnus.
DEEP-SKY OBJECTS
With dark skies, ideal viewing conditions, and powerful astronomical
binoculars, you can observe a number of amazing objects outside
our solar system - commonly referred to as “deep-sky objects”.
These include star clusters, galaxies, gaseous nebulas, and more.
With primary conditions, your binoculars are well equipped to gather
the light necessary to view these objects, but you will need to find a
viewing site well away from light pollution and give your eyes plenty
of time to fully dark-adapt. As you continue to view, your eyes will
become trained, and more and more subtle details from these objects
will become apparent. Don’t expect to see color, however, as human
eyes are not sensitive enough to distinguish color from faint light.
COOL VIEWS WITH YOUR
ZHUMELL ASTRONOMICAL BINOCULARS
STARHOPPING
Starhopping is the most common and simplest way to reliably track
down objects in the night sky. It uses relative positioning, beginning
at a star with a known location and progressing to other stars closer
and closer to the destination object. It’s been used for hundreds of
years, and - with practice - will never let you down when finding an
object. Starhopping can be very difficult at first, so be patient and
keep trying!

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COOL VIEWS WITH YOUR
ZHUMELL ASTRONOMICAL BINOCULARS
You will need a small number of additional resources to successfully
employ starhopping as your night-sky positioning technique. A star
chart or atlas that shows stars to at least magnitude 5 is required.
Choose one that shows the positions of many deep-sky objects
to give yourself a wealth of options. If you don’t already know the
positions of the constellations in the night sky, you will need a
planisphere as well.
Begin by choosing brighter deep-sky objects as your destination.
The brightness of an object is measured by its visual magnitude;
the brighter an object, the lower its magnitude. Choose an object
with a visual magnitude of 9 or lower. Most beginners start with
the Messier objects, some of the brightest and most beautiful
deep-sky objects, first catalogued about 200 years ago by French
astronomer Charles Messier.
Using your star chart, determine in which constellation your
object lies and locate that constellation in the night sky. Turn your
binoculars to face this general direction. Find the brightest star in
this constellation and center your view on it. Consult your star chart
again, and determine the next brightest star between your currently
focused star and your object destination. Move your binoculars
slightly to focus and center this next star. Continue on this course,
using each star as a guidepost for the next, until you reach the area
in the sky in which the object of your hunt should be seen. Center
the object and bring it into focus. You’ve just found a deep-sky
object. If the object is still not in view, retrace your starhopping
steps and start again. Remember, expertise in this hobby will
require both patience and practice.
Good luck out there!

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ASTRONOMY TERMINOLOGY
DECLINATION (DEC.) - The astronomical
equivalent of latitude. Declination describes
the angle of a celestial object above or below
the celestial equator. The sky over the northern
hemisphere has a positive declination. The sky over
the Southern hemisphere has a negative declination.
For example, Polaris (the North Star) which lies nearly
directly over the North Pole, has a declination
value of 90°.
RIGHT ASCENSION (R.A.) -
The astronomical equivalent of longitude. Right
ascension measures the degree of distance of
a star to the east of where the ecliptic crosses
the celestial equator. R.A. is measured in hours,
minutes, and seconds as opposed to degrees. It
is different than the term “meridian”, which is used
in referring to lines of longitude. Right ascension
is referred to in “hour circles”. There are 24 hour
circles of right ascension which run from the north
to south celestial poles.
CELESTIAL EQUATOR - The celestial equator is
the line of declination which lies directly above the
Earth’s equator. The celestial equator lies halfway
between the north and south celestial poles and
serves as the 0° point in measuring declination.
ECLIPTIC - The ecliptic is the apparent path of
the sun through the sky over the course of the
year. Since we view the sun from different angles
throughout the year, it appears to move in relation
to other stars. The vernal (spring) and autumnal
(fall) equinoxes lie at the points where the ecliptic
intersects the celestial equator. The vernal equinox
is where right ascension is at 0h (hours). The
autumnal equinox can be found at 12h R.A.
ZENITH - The zenith is the point in the celestial
sphere directly above your head. The zenith varies
depending upon your location. In general, the
declination point of your zenith is equal to the
latitude at which you are standing on Earth.
EPHEMERIS - The ephemeris of a planet or the sun
or the moon is a table giving the coordinates of the
object at regular intervals of time. The coordinates
will be listed using declination and right ascension.
Other information such as distance and magnitude
may be listed in ephemerides (plural of ephemeris).
ALTITUDE - The altitude of a celestial object is the
angular distance of that object above the horizon.
The maximum possible altitude is the altitude of an
object at the zenith, 90°. The altitude of an object
on the horizon is 0°. Altitude is measured from your
point of observation and does not directly correlate
to points on the celestial sphere.
AZIMUTH - Azimuth is the angular distance
around the horizon measured eastward in degrees
from the North Horizon Point. Thus, the North
Horizon Point lies at an azimuth of 0°, while the
East Horizon Point lies at 90°, and the South
Horizon Point at 180°. Azimuth is measured from
the point of observation and does not directly
correspond to points on the celestial sphere.
ANGULAR DISTANCE - Angular distance is the
size of the angle through which a telescope tube
or binocular aiming at one object must be turned in
order to aim at another object. If you must rotate the
equipment from the zenith to the horizon, the angular
distance between the two points would be 90°.

WARRANTY
Zhumell products are designed to provide you with the highest quality and
best value available, which is why we’re proud to offer a world-class warranty
on all of our products. All Zhumell binoculars are covered by a 25-year
no-fault warranty.
To obtain warranty service, the damaged equipment must be returned
to Zhumell. Our Customer Care associates will be happy to assist you in
completing this return to get your Zhumell in working order as quickly as
possible. There is a $15 surcharge associated with warranty returns to cover
return shipping and handling.
For more information, contact information, and to download the Zhumell
Warranty Return Form, please visit http://www.zhumell.com.