Celestron XLT series - Manual (Page 33)

After looking at the night sky for a while you may want to try photographing it. Several forms of photography are
possible with your telescope, including terrestrial and celestial photography. Both of these are discussed in moderate
detail with enough information to get you started. Topics include the accessories required and some simple techniques.
More information is available in various books on the subject matter.
Below is described the traditional photographic methods with traditional equipm
igital cameras have become very popular and you can use this latest technology to take images through telescop
ent. During the last several years,
es and
it is re Lunar and
Planetary es for
fantasti
In addition
a camera -
but not jus s state-of-the-art
equipm y or mirror lock up. Here are the mandator eatures a
camera needs for celestial photography. First, a “B” setting me exposures and this excludes point
and shoot cameras and limits the selection to SLR c ost common type of 35mm camera on the market
today.
Second, the
s use the battery to
keep the sh
closes, whether osure or ot. Look for a camera that has a manual shutter when
operating in the time exposure mode. Canon, Olympus, Nikon, Pentax, Minolta, and others have made such camera
bodies.
ty of
is not
00-percent functional. The light meter, for example, does not have to be operational since you will be determining the
d
latively simple. In addition, CCD cameras (specifically made for astrophotography as well as
photography have become more economical for hobbyists to procure and have opened new avenu
c images.
to the specific accessories required for each type of celestial photography, there is the need for
t any camera. The camera does not have to have many of the features offered on today'
ent. For example, you don't need auto focus capabilit y f
which allows for ti
ameras, the m
“B” or manual setting should NOT run off th battery. Many new electronic camera
utter open during time exposures. Once the batteries are drained, usually after a few minutes, the shutter
you were finished with the exp
e
n
The camera must have interchangeable lenses so you can attach it to the telescope and so you can use a varie
lenses for piggyback photography. If you can't find a new camera, you can purchase a used camera body that
1
exposure length manually.
You also need a cable release with a locking function to hold the shutter open while you do other things. Mechanical
and air release models are available.
P P i i g g g g y y b b a a c c k k P P h h o o t t o o g g r r a a p p h h y y
se you are photographing with a low power lens and
ng
tonian telescope, use
e piggyback adapter screw located on the top of the tube mounting ring. For the Schmidt-Cassegrain
phy, it should done from a dark sky observing site. Light
pollution around major urban areas washes out the fai t light of deep-sky objects. You can still practice
from less ideal skies.
1. Polar align the telescope (using one of the methods de cribed earlier) and start the optional motor drive.
2. Load your camera with slide film, ISO 100 or faster, or print film, ISO 400 or faster!
2a. When using digital cameras, experiment with vari us settings and read the camera instructions as each
is somewhat different than SLR cameras.
3. Set the f/ratio of your camera lens so that it is a half stop to one full stop down from completely open.
The easiest way to enter the realm of deep-sky, long exposure astrophotography is via the piggyback
method. Piggyback photography is done with a camera and its normal lens riding on top of the telescope.
Through piggyback photography you can capture entire constellations and record large scale nebulae that
re too big for prime focus photography. Becau a
guiding with a high power telescope, the margin for error is very large. Small mistakes made while guidi
the telescope will not show up on film. To attach the camera to the refractor or New
th
telescope there is an optional Piggyback Camera Mount available. The cameras have a threaded hole at the
bottom of the camera where the piggyback screw threads into.
As with any form of deep-sky photogra
be
n
s
o
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