Sky & Telescope - April 2024 - 68

S&T Test Report
minor tweak of the focus knob was
usually required. The only issue with
focusing turned out to be user error - I
tried to focus on a double star, showing
two overlapping Bahtinov diffraction
patterns. At first, I thought the scope
was grossly out of collimation, but I
quickly determined that double stars are
not good focusing targets!
Collimation held very well, even
after driving with the system in my car
some 320 kilometers (200 miles) to the
Stellafane Telescope Making Convention
in Springfield, Vermont, with
the last mile being bumpy dirt roads.
Indeed, collimation held rock-steady for
the several months I used the scope.
With a focal length of 456 millimeters,
the eQuinox 2 is suited to many
deep-sky objects, except perhaps small
planetary nebulae. While it can record
the entire lunar disk, the OTA's focal
length is too short for satisfying planetary
imaging. It can resolve Saturn's
rings and two bands on Jupiter, but not
much more than that.
Because the telescope has an altazimuth
mount, over time the imaging
field rotates. So, when taking a series of
exposures over an extended period, the
corners of the images may not receive
light from all exposures. As a result,
these parts of the frame will be noisier
than the center. All this is hidden when
the user chooses Frame on the Observation
page, which appears as a circular
frame that covers the noisier corners of
the field.
Electronically Assisted
Astronomy in Action
The Unistellar app's catalog has a generous
list of objects, with lots of details
for each. It also includes the ability to
move the system to any location manually
entered in either by RA and declination
or by alt-azimuth coordinates,
and even manually using the Joystick
feature. Slewing to a selected object
never took more than about 30 seconds.
The scope plate-solves a field or
two along its way to the chosen target
by moving for a few seconds, stopping
to take a pointing exposure, and then
slewing off to its final destination. It
rarely took more than three steps to
reach the desired object.
Only two things seemed to confuse
the eQuinox 2 when it attempted to
slew to a target. The first is a partly
cloudy sky. If the scope stopped on a
cloud through which no stars were visible,
it wouldn't continue on, and I had
to re-launch the slew. The other impediment
was slewing to the Moon. As the
scope approached, the imaging field was
filled with lunar glare that overwhelmed
the stars and stopped the device in its
tracks. When this happened, I could use
the Joystick in manual mode to nudge
the scope on target.
When a deep-sky object is acquired,
you can tap the Enhanced Vision button
to begin stacking images. After 10
or 15 seconds the image seen on your
handset transforms from just a few
stars to many stars plus your target. As
time goes on, more images are stacked,
and the image becomes less noisy and
displays fainter stars. Users need to
manually determine total exposure
times required and press a Camera
button to save an image of an object.
Unless you manually intervene, the
system continues to stack additional
frames. I often saved pictures at several
points while on a target.
I found the Wi-Fi connection of
the eQuinox 2 to be very reliable up
to a distance of about 30 meters (100
pLeft: The Sony Starvis IMX347 CMOS detector within the eQuinox 2 has a generous field of view - large enough to reveal any miscollimation and
even coma in the corners of the frame, as this image of M45 reveals. Careful attention to collimation can preclude many of these issues. Right: The
circular Frame option in the Observation section can mask some of these deficiencies.
68 APRIL 2024 * SKY & TELESCOPE
PETER BEALO (2)

Sky & Telescope - April 2024

Table of Contents for the Digital Edition of Sky & Telescope - April 2024