7
system, leading to overexposure. For planetary imaging, it’s best to manually adjust
the exposure.
From the tabs on the left, you can also adjust the gain, gamma, contrast, and satura-
tion, among other variables such as color shifts. Gain allows you to make the chip
more sensitive at the same exposure value, at the expense of more electronic noise
in the image. Try to keep the gain fairly low in order to produce a smooth image.
First adjust the exposure value, and if
needed, then try adjusting gain to produce
the desired image.
Astronomical Imaging
Now that you’re familiar with basic camera
and software operation, it’s time to take the
SS-V out at night under the stars to capture
some astronomical images. We recom-
mend starting with the Moon, as it is easy
to acquire into the camera’s field of view,
and typically does not require stacking of
multiple exposures as planetary images do.
Imaging the Moon
Imaging the Moon is much like imaging ter-
restrial objects during the day. Since the
exposure is very short, it is not critical that
the telescope be precisely polar aligned.
When the moon is past half full, it is hard to
get detail due to the tremendous glare off
of the lunar surface. Most detail, even on
a sliver of a moon, will be at the termina-
tor (that tiny thin line between the shadow
and light, see
Figure 6
). To get more of
the moon in the image, a focal reducer
will need to be used. For close-ups of cra-
ters use a Barlow lens (see “Using Focal
Reducers and Barlow Lenses”).
Imaging Planets
The best planetary images will be obtained
by stacking (combining) many individual
images in order to improve image con-
trast, brightness, and detail
(Figure 7, 8)
.
A great way to obtain images for stacking
is to take several seconds of video of the
planet, then break the video into individual
frames for stacking. Since the SS-V has a
video mode, you can literally obtain hun-
Figure 6.
The moon’s surface detail
looks the best along the terminator.
Figure 7.
Jupiter with Ganymede
and shadow in transit.
Left.
Live image
Right. 500 frames Aligned, stacked
and enhanced using Registax Image
Processing Software (Windows). Image
taken with Orion 180mm Mak-Cass
telescope.
Figure 8.
Saturn.
Left.
Live image
Right. 100 frames Aligned, stacked
and enhanced using Lynkeos Image
Processing Software (Mac OS X). Image
taken with Orion 180mm Mak-Cass
telescope.