Table of Contents
Advertisement
To convert degrees to feet at 1,000 yards, which is more use-
ful for terrestrial observing, simply multiply by 52.5. Continuing
with our example, multiply the angular field 2.2° by 52.5. This
produces a linear field width of 115.5 feet at a distance of one
thousand yards.
General observing Hints
When working with any optical instrument, there are a few
things to remember to ensure you get the best possible
image:
• Never look through window glass. Glass found in house-
hold windows is optically imperfect, and as a result, may
vary in thickness from one part of a window to the next.
This inconsistency can and will affect the ability to focus
your telescope. In most cases you will not be able to
achieve a truly sharp image, while in some cases, you
may actually see a double image.
• Never look across or over objects that are producing
heat waves. This includes asphalt parking lots on hot
summer days or building rooftops.
• Hazy skies, fog, and mist can also make it difficult to
focus when viewing terrestrially. The amount of detail
seen under these conditions is greatly reduced. Also,
when photographing under these conditions, the pro-
cessed film may come out a little grainier than normal
with lower contrast and underexposed.
• If you wear corrective lenses (specifically glasses), you
may want to remove them when observing with an eye-
piece attached to the telescope. When using a camera,
however, you should always wear corrective lenses to
ensure the sharpest possible focus. If you have astigma-
tism, corrective lenses must be worn at all times.
celestial observing
With your telescope set up, you are ready to use it for observ-
ing. This section covers visual observing hints for both solar
system and deep sky objects as well as general observing
conditions which will affect your ability to observe.
observing the Moon
Often, it is tempting to look at the Moon when it is full. At this
time, the face we see is fully illuminated and its light can be
overpowering. In addition, little or no contrast can be seen
during this phase.
One of the best times to observe the Moon is during its partial
phases (around the time of first or third quarter). Long shad-
ows reveal a great amount of detail on the lunar surface. At
low power you will be able to see most of the lunar disk at
one time. Change to higher power (magnification) to focus in
on a smaller area. Choose the lunar tracking rate from the
StarSeeker's MENU tracking rate options to keep the moon
centered in the eyepiece even at high magnifications.
lunar observing Hints
• To increase contrast and bring out detail on the lunar sur-
face, use eyepiece filters. A yellow filter works well at improv-
18
ing contrast while
a neutral density
or polarizing filter
will reduce over-
all surface bright-
ness and glare.
observing the
Planets
Other fascinating
targets include
the five naked
eye planets. You can see Venus go through its lunar-like phas-
es. Mars can reveal a host of surface detail and one, if not
both, of its polar caps. You will be able to see the cloud belts
of Jupiter and the great Red Spot (if it is visible at the time you
are observing). In addition, you will also be able to see the
moons of Jupiter as they orbit the giant planet. Saturn, with its
beautiful rings, is easily visible at moderate power.
Planetary observing Hints
• Remember that atmospheric conditions are usually the limit-
ing factor on how much planetary detail will be visible. So,
avoid observing the planets when they are low on the horizon
or when they are directly over a source of radiating heat, such
as a rooftop or chimney. See the "Seeing Conditions" section
later in this section.
• To increase contrast and bring out detail on the planetary
surface, try using color eyepiece filters.
observing the sun
Although overlooked by many amateur astronomers, solar
observation is both rewarding and fun. However, because
the Sun is so bright, special precautions must be taken when
observing our star so as not to damage your eyes or your
telescope.
Never project an image of the Sun through the telescope.
Tremendous heat build-up may result inside the optical tube.
This can damage the telescope and/or any accessories
attached to the telescope.
For safe solar viewing, use a solar filter that reduces the
intensity of the Sun's light, making it safe to view. With a filter
you can see sunspots as they move across the solar disk and
faculae, which are bright patches seen near the Sun's edge.
solar observing Hints
• The best time to observe the Sun is in the early morning or
late afternoon when the air is cooler.
• To center the Sun without looking into the eyepiece, watch the
shadow of the telescope tube until it forms a circular shadow.
• To ensure accurate tracking, be sure to select solar tracking
rate.
observing Deep sky objects
Deep sky objects are simply those objects outside the bound-
aries of our solar system. They include star clusters, planetary
nebulae, diffuse nebulae, double stars and other galaxies out-
Advertisement
Table of Contents
