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Helpful
Hint
Once the worm gear is indexed, it will not need to be positioned again until the telescope is turned-off. So, to give yourself more
time to prepare for guiding, it is best to restart PEC recording after the worm gear has found its index.
6.
After 8 minutes PEC will automatically stop recording.
7.
Point the telescope at the object you want to photograph and center the guide star on the illuminated cross hairs and you
are ready to play back the periodic error correction.
8.
Once the drive's periodic error has been recorded, use the Playback function to begin playing back the correction for
future photographic guiding. If you want to re-record the periodic error, select Record and repeat the recording
processes again. The previously recorded information will be replaced with the current information. Repeat steps 7
and 8 to playback the PEC corrections for your next object.
Does the PEC function make unguided astrophotography possible? Yes and no. For solar (filtered), lunar, and piggyback (up to
200mm), the answer is yes.
astrophotography. The optional Reducer/Corrector lens reduces exposure times making the task of guiding a little easier.
When getting started, use fast films to record as much detail in the shortest possible time. Here are proven recommendations:
Ektar 1000 (color print)
Konica 3200 (color print)
Fujichrome 1600D (color slide)
3M 1000 (color slide)
Scotchchrome 400
T-Max 3200 (black and white print)
T-Max 400 (black and white print)
As you perfect your technique, try specialized films, that is films that are designed or specially treated for celestial photography.
Here are some popular choices:
Ektar 125 (color print)
Fujichrome 100D (color slide)
Tech Pan, gas hypered (black and white print)
T-Max 400 (black and white print)
There is no exposure determination table to help you get started. The best way to determine exposure length is look at previously
published photos to see what film/exposure combinations were used. Or take unguided sample photos of various parts of the sky
while the drive is running. Always take exposures of various lengths to determine the best exposure time.
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Your CPC makes an excellent telephoto lens for terrestrial (land) photography. Terrestrial photography is best done will the
telescope in Alt-Az configuration and the tracking drive turned off. To turn the tracking drive off, press the MENU (9) button on
the hand control and scroll down to the Tracking Mode sub menu. Use the Up and Down scroll keys (10) to select the Off option
and press ENTER. This will turn the tracking motors off, so that objects will remain in your camera's field of view.
Metering
The CPC has a fixed aperture and, as a result, fixed f/ratios. To properly expose your subjects photographically, you need to set
your shutter speed accordingly. Most 35mm SLR cameras offer through-the-lens metering which lets you know if your picture is
under or overexposed. Adjustments for proper exposures are made by changing the shutter speed. Consult your camera manual for
specific information on metering and changing shutter speeds.
Reducing Vibration
Releasing the shutter manually can cause vibrations, producing blurred photos. To reduce vibration when tripping the shutter, use a
cable release. A cable release keeps your hands clear of the camera and lens, thus eliminating the possibility of introducing
vibration. Mechanical shutter releases can be used, though air-type releases are best.
However, even with PEC, off-axis guiding is still mandatory for long exposure, deep sky
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