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S&T Test Report
AstroFX Software
One of the most attractive features of
Nightscape, especially for those relatively
new to processing astronomical images,
is the included AstroFX software. It
transforms the work of making exposures
and, more importantly, the tedious
aspects of processing images, to a few
mouse clicks.
I ran the software on a recent-model Dell desktop
machine with an AMD Athlon II 2X processor, 4 gigabytes
of RAM, and Windows 7. It installed with no problems
and the software acquired the Nightscape camera the fi rst
time I started the program. Launching AstroFX brings
up an unconventional-looking screen for those who are
familiar with many camera-control and image-processing
programs. The screen does, however, remind you that it’s
This stack of 25 fi ve-minute exposures of NGC 1977, informally known as the
Running Man Nebula, north of the Orion Nebula, was made with the 12½-inch
f/4 refl ector and the Nightscape’s pixels binned 2x2.
66 May 2012 sky & telescope
As explained in the accompanying text, one of Nightscape’s biggest
strengths is the supplied AstroFX software for controlling the
camera and processing its images. All the software’s functions
are operated from a small dialog box that can be placed anywhere
on your computer screen. A Nightscape raw image before color
correction with the Stretch function is shown in this view.
a Celestron product with an orange-on-black color scheme.
Most AstroFX functions are located in a small rectangular
window that you can move to any place on your computer
monitor. There are pull-down menus for making
focus, bias, fl at, and dark frames, as well as your normal
exposures. The whole sequence of shooting and processing
images is organized into seven steps. Exposing an
image is done with functions under the Snap tab, and the
subsequent processing steps of Stack, Stretch, Smooth,
Sharpen, Saturate, and Share are listed on tabs to its right.
Each step has user adjustable sliders in addition to an
“Auto” button (more about this in a minute).
Rather than a monochrome “raw” image that some
one-shot color cameras display after an exposure, AstroFX
shows a color image, but the initial colors are far from
accurate. Most showed a greenish sky background.
Applying the Stretch function turns the colors to a more
accurate hue.
Acquiring and composing a celestial target is best done
using the camera’s quarter-resolution setting because
readout and display of the image happens in about 3
seconds. The binned pixels also have greater sensitivity,
showing the general shape and extent of brighter deepsky
objects in exposures 1 to 10 seconds long.
Once you’ve composed an image, AstroFX helps you
quickly achieve sharp focus. You do this by drawing a
mouse-selectable subframe around a single star — the
smaller the subframe, the faster the readout of the focus
images. Large digits display the star’s diameter measured
in pixels at the so-called full-width half-maximum
(FWHM) part of its intensity profi le. Sharpest focus
occurs when this value is the smallest you can make it