Instruction manual

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5. Wait for the vibration caused by releasing the shutter to diminish. Also, wait for a moment of good seeing.
6. Remove the black card from in front of the telescope for the duration of the exposure (see accompanying table).
7. Replace the black card over the front of the telescope.
8. Close the camera's shutter.
Advance the film and you are ready for your next exposure. Don't forget to take photos of varying duration and keep
accurate records of what you have done. Record the date, telescope, exposure duration, eyepiece, f/ratio, film, and some
comments on the seeing conditions.
The following table lists exposures for eyepiece projection with a 10mm eyepiece. All exposure times are listed in
seconds or fractions of a second.
Planet ISO 50 ISO 100 ISO 200 ISO 400
Moon4211/2
Mercury16842
Venus 1/2 1/4 1/8 1/15
Mars16842
Jupiter8421
Saturn16842
Table 9-2
The exposure times listed here should be used as a starting point. Always make exposures that are longer and shorter than
the recommended time. Also, take a few photos at each shutter speed. This will ensure that you get a good photo. It is
not uncommon to go through an entire roll of 36 exposures and have only one good shot.
NOTE:
Don't expect to record more detail than you can see visually in the eyepiece at the time you are photographing.
Once you have mastered the technique, experiment with different films, different focal length eyepieces, and even
different filters.
Effective Focal Length
The effective focal length of the optical system for eyepiece projection is given by this formula:
E F L Magnification DF
...
=×
where
DF
is the distance from the center of the eyepiece to the film and magnification is the focal length of the telescope
divided by the focal length of the eyepiece.
Effective Magnification
To determine the magnification when using eyepiece projection, use the equation
EM
EFL
..
...
=
50
where
E.F.L
. is the effective focal length ,
in millimeters
and
E.M.
is the effective magnification.