Sky & Telescope - July 2024 - 70

S&T Test Report
as it can see stars at each of its three
calibration stops.
App Control
As noted earlier, the Dwarf II is controlled
by the DWARFLAB app. Upon
launching the app, hitting Connect first
links to the Dwarf II via Bluetooth,
then asks to connect to its 5 GHz Wi-Fi
hot spot. Once established, I found the
Wi-Fi connection was usually reliable,
working from up to 6 to 9 meters away
(20 to 30 feet) and through one wall or
glass doors.
The current version 2.1.0 of the app
contains a database of 550 targets,
including 68 stars, 52 nebulae, 98 galaxies,
and 323 star clusters. While the
latter category seems overly represented,
it mistakenly contains quite a few
objects that are actually nebulae.
Although the DWARFLAB app
database contains no comets or asteroids,
nor any means of adding them,
users can enter the RA and declination
coordinates of any targets. However, as
of this writing, the app does not include
an internal star atlas for visualizing
where targets are located and that
would allow users to " tap and go. " (The
company plans to add such an atlas in a
future update.)
The lack of any " Tonight's Best " target
list (as of early 2024) requires users
to know the sky well enough to decide
what to shoot among the hundreds of
targets on offer. Having the app provide
more information about objects
would also make using the Dwarf II
more educational and enhance its
appeal for new astronomers.
The app offers options for adjustThis
shows a stack of 120, 15-second exposures (totaling more
than 40 minutes) of the Andromeda Galaxy, M31, taken when it was
near the zenith, a worst case for tracking with an alt-azimuth-mounted
scope. The stars are trailed, and the corners show noisy artifacts.
ing the exposure time, sensor gain (the
default setting of 80 proved good),
how many subframes to shoot (up to
the maximum of 999), and whether
the internal infrared-blocking filter is
engaged (Cut) or not (Pass). I found
the latter setting best for most deepsky
objects. While these are all helpful
settings for experienced imagers, the
choices can be a source of confusion to
new users.
Most annoyingly, after completing
a target the exposure time reverts to a
default of one second (the shutter speed
the device uses for plate solving when
finding the next target). Other user settings,
thankfully, remain in effect from
target to target.
Image Quality
I tested the Dwarf II under rural skies,
but often on nights with bright moonlight
or with reduced transparency due
to wildfire smoke. I was always pleasantly
surprised by how much it could
show even under poor conditions. Citybound
users should be able to image
bright deep-sky objects that would be
hard to see visually.
However, even under clear, darkThis
image is also a stack of 120, 15-second exposures with
M31 overhead, but with the Dwarf II tipped to track as an equatorial
telescope. It needed only to be roughly polar aligned to reduce
corner artifacts and trailing for zenith targets.
70 JULY 2024 * SKY & TELESCOPE
sky conditions, I found the results to
be noisy and star images soft due to
lens aberrations. You can't expect great
resolution from a one-inch lens, and
an uncooled sensor with tiny pixels is
bound to be noise-prone.
To mitigate the worst of the noise,
Sky & Telescope - July 2024

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