Celestial Photography - Celestron C4.5 Instruction Manual

CELESTIAL PHOTOGRAPHY
40
Celestial Photography
After looking at the night sky for awhile you may want to try photographing
it. Several forms of celestial photography are possible with your Celestron
C4.5 telescope. Two of the most common forms of celestial photography, in
order of difficulty are short exposure prime focus and eyepiece projection,
both of which can be done from urban areas. Each of these is 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 some of the publications listed at the end of this manual.
In addition to the specific accessories required for each type of celestial
photography, there is the need for a camera — but not just any camera. The
camera does not need to have many of the features offered on today's state-
of-the-art equipment. For example, you don't need auto focus capability or
mirror lock up. Here are the mandatory features a camera needs for celestial
photography. First, a B' setting which allows for time exposures. This
excludes point and shoot cameras and limits the selection to SLR cameras,
the most common type of 33mm camera on the market today.
Second, the 'B' or manual setting should not run off the battery. Many new
electronic cameras use the battery to keep the shutter open during time
exposures. Once the batteries are drained, usually after a few minutes, the
shutter closes, whether you have finished with the exposure or not. Look for
a camera that has a manual shutter when operating in the time exposure
mode. Olympus, Nikon, Minolta, Pentax, Canon and others have made such
camera bodies and some still do!
The camera must have interchangeable lenses so you can attach it to the
telescope. If you can't find a new camera, you can purchase a used camera
body that is not 100-percent functional. The light meter does not have to be
operational since you will be determining the exposure length manually.
The camera should, however, allow you to select the shutter speed.
Use a cable release with a locking function to hold the shutter open while
you do other things. Mechanical and air releases are available.