Celestron C4.5 - Short Exposure Prime Focus 4]

Short Exposure Prime
Focus
Short exposure prime focus photography is the best way to begin recording
celestial objects. It is done with the camera attached to the telescope without
an eyepiece or camera lens in place. To attach your camera, you need the
Celestron T-Adapter (#93634-A) and a T-Ring for your specific camera (i.e.,
Minolta, Nikon, Pentax, etc.). The T-Ring replaces the 35mm SLR camera’s
normal lens. Prime focus photography allows you to capture the entire lunar
disk or entire solar disk (if using the proper filter). To attach your camera to
your C4.5:
1. Remove all visual accessories.
2. Thread the T-Ring onto the T-Adapter.
3. Mount your camera body onto the T-Ring the same as you would any
other lens.
4. Thread the T-Adapter onto the focusing draw tube of the Celestron C4.5
while holding the camera in the desired orientation (either vertical or
horizontal).
With your camera attached to the telescope, you are ready for prime focus
photography. Start with an easy object like the Moon. Here’s how to do it:
1. Load your camera with film that has a moderate-to-fast speed (i.e., ISO
rating). Faster films are more desirable when the Moon is a crescent.
When the Moon is near full, and at its brightest, slower films are more
desirable. Here are some film recommendations:
T-Max 100
T-Max 400
Any 100 to 400 ISO color slide film
Fuji Super HG 400
2. Center the Moon in the field of your C4.5 telescope.
3. Focus the telescope by turning the focus knob until the image is sharp.
4. Set the shutter speed to the appropriate setting (see table 7-1).
5. Trip the shutter using a cable release.
6. Advance the film and repeat the process.
anemias | 15056 | 15070 | 5020 | 50% |
| Fan — | 1/60 | i/25 | 1250 | 1/80 |
Table 7-1
Above is a listing of recommended exposure times when photographing
the Moon at the prime focus of your Celestron C4.5.
Celestial Photography + 41