9
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 10
). 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 contrast,
brightness, and detail (
Figure 11
).
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 SSUEII has
a maximum frame rate of 30 frames per
second at maximum resolution, you can literally obtain hundreds of images for
stacking in seconds! You save time by taking one video instead of dozens of indi-
vidual pictures!
Since you will be taking multiple images over a period of time, it is important you
have a decent polar alignment in order to keep the planet within the field of view
of the camera. To this end, having a motor drive (at least single-axis) will also be
helpful. Otherwise, you will periodically need to rotate the R.A. slow-motion knob to
keep the planet within the camera’s field.
Tips
Focusing
One of the hardest things to do in planetary imaging is achieving good focus. You
can make this process easier by simply watching the
Live Video
window to focus.
Depending upon the viewing conditions you may notice that the image goes in and
out of focus
-
this is due to viewing conditions. This is to be expected and one of
the reasons why post processing software can bring out the best in your captured
images. Focus as best as possible with the average frame being at best focus to
ensure more in focus frames than out of focus. Image processing software can
then be used to select the best frames to combine for best results.
Refocus often throughout your imaging session. This ensures at least some of your
images will have an excellent focus. It is also not uncommon for telescope move-
Figure 10.
The moon’s surface detail
looks the best along the terminator.
Figure 11.
Planetary Stacking.