The eyepiece inserted must be able to fit into the Eyepiece Projection Camera Adapter. (The
biggest 31.7mm eyepiece allowable is 48mm in outer diameter and 90mm in length.) It is
ideal for taking close-ups of small regions of the moon and details of the planets.
FYI: Using a method of Afocal Imaging photography with a compact digital camera is also
good for taking photos of the planets. A small CCD area produces a large image of the
planets without excessively boosting magnification. This will result in a shorter exposure
time and will help to avoid the influence of atmospheric turbulence (scintillation).
Tips on Successful Photography
1. Take photos in conditions of good seeing. The seeing is how the image of a celestial
object can be seen in random turbulent motion in the atmosphere. In bad seeing, light
from the celestial object is bent or diffused and the image appears to shiver constantly.
Shooting an object at low altitude may also blur the image.
2. Use a commercially available camera cable release to release the shutter on the camera.
As the focal length of the telescope becomes longer by compound optics, it will cause
blurring by vibration even if the shutter is pressed gently with your finger.
3. Put the object precisely in focus. The focus range of an astronomical telescope is
narrow due to its long focal length. The point of the best focus varies by changes in the
outside temperature.
4. Leave the telescope outside until it becomes equivalent to the ambient temperature.
It may take one or two hours for a reflecting or catadioptric telescope to calm down the air
current inside the optical tube before start photographing.
Calculating a Focal Length and an F-number of Compound Optical System
Apply the formula below, in the box, to determine the size of a celestial object on the focal
plane and the duration of exposure.
(Example)
Telescope
: D=80mm f=910mm
Eyepiece :
LV20mm
(46x)
Camera : 35mm-size SLR camera with Pentax K-mount (Flange-back: 45.5mm)
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