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Astrophotography, Care and maintenance – Orion 9877 User Manual

Page 14

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Determine in which constellation the object lies. Now, find the
constellation in the sky. If you do not recognize the constella-
tions on sight, consult a planisphere. The planisphere gives
an all-sky view and shows which constellations are visible on
a given night at a given time.

Now, look at your star chart and find the brightest star in the
constellation that is near the object you are trying to find.
Using the finder scope, point the telescope at this star and
center it on the crosshairs. Next, look again at the star chart
and find another suitably bright star near the bright star cur-
rently centered in the finder. Keep in mind that the field of view
of the finder scope is approximately 7°, so you should choose
another star that is no more that 7° from the first star, if possi-
ble. Move the telescope slightly, until the telescope is cen-
tered on the new star.

Continue using stars as guideposts in this way until you are at
the approximate position of the object you are trying to find
(Figure 14). Look in the telescope’s eyepiece, and the object
should be somewhere within the field of view. If it’s not, sweep
the telescope carefully around the immediate vicinity until the
object is found.

If you have trouble finding the object, start the starhop again
from the brightest star near the object you wish to view. This
time, be sure the stars indicated on the star chart are in fact
the stars you are centering in the eyepiece. Remember, the
finder scope (and main telescope eyepiece, for that matter)
gives an inverted image, so you must keep this in mind when
starhopping from star to star.

Terrestrial Viewing

The SkyView Pro 127mm not only excels at astronomical
observing, it’s great for terrestrial (land) viewing too. The
equatorial mount, however, is not well suited for land viewing
due to its motion about R.A. and Dec. axes instead of altitude
(vertical) and azimuth (horizontal) axes. Because of this, we
recommend removing the optical tube from the SkyView Pro
mount and placing it on an appropriate photo-style tripod.
Connect the optical tube to a photo tripod by threading the tri-
pod’s 1/4"-20 shaft into the hole on the tube’s mounting block.

The included mirror star diagonal, while preferred for astro-
nomical observing because of its viewing angle and better
resolution, is not optimal for land viewing because it inverts
images from left-to-right. We recommend purchasing an
optional 45° correct-image diagonal for terrestrial observing;
it provides a more comfortable viewing angle for land viewing
and an image that is oriented the same as the naked eye. In
addition, an optional correct-image finder scope will be useful
for aiming the optical tube.

For terrestrial viewing, it’s best to stick with low power eye-
pieces that yield a magnification under 100x. At higher pow-
ers, images rapidly lose sharpness and clarity due to “heat
waves” caused by Sun-heated air.

Remember to aim well clear of the Sun, unless the front of the
telescope is fitted with a professionally made solar filter and
the finder scope is covered with foil or some other completely
opaque material.

8. Astrophotography

With an optional camera adapter, the SkyView Pro 127mm
EQ becomes a 1540mm f/12.1 telephoto lens for a single-lens
reflex camera. For long-distance terrestrial or astronomical
photography, you need only a T-ring for your specific camera
model. The T-ring attaches to your camera and threads onto
the eyepiece adapter (first remove eyepiece and diagonal),
coupling the camera body to the telescope. Use the camera’s
viewfinder to frame the picture. Use the telescope’s focuser to
focus the image.

You may want to consider using a remote shutter release
instead of the shutter release on the camera. Touching the
camera can vibrate the system and blur the resulting photo-
graphic image.

9. Care and Maintenance

Transporting

The included padded carrying case provides an excellent way
to transport the optical tube and its accessories. Loosen the
safety thumbscrew and the mounting plate securing knob and
remove the optical tube from the mount. Make sure to have a
firm grip on the tube as it releases from the mount. To place
the optical tube in the case, the eyepiece, diagonal, finder
scope and bracket must be removed from the tube. When
removing the eyepiece and diagonal, remember to first

Figure 14.

Starhopping is a good way to locate hard-to-find

objects. Refer to a star chart to map a route to the object that uses
bright stars as guideposts. Center the first star you’ve chosen in the
finder scope and telescope eyepiece (1). Now move the scope
carefully in the direction of the next bright star (2), until it is
centered. Repeat (3 and 4). The last hop (5) should place the
desired object in the eyepiece.