Sky & Telescope - August 2021 - 55

AUTHOR AT TELESCOPE: LAURIE REDFERN
lots and lots of shots. Bear in mind
how much better things are today than
they were for previous generations
of astrophotographers, whose storage
medium usually consisted of 36
exposures on a roll of fi lm. Back then,
you had to wait days for your results,
making the SAAS process very longterm
and expensive! Thankfully, times
have changed.
Most beginning astrophotographers
would be hard-pressed to fi ll up a single
32GB memory card in one night, let
alone one with a capacity of 64GB or
128GB. But as you become more ambitious,
that could change. A typical RAW
image fi le from a current-model DSLR
or Mirrorless camera can exceed 70MB,
and thousands of video frames will eat
up signifi cant storage.
Thankfully, memory cards are relatively
inexpensive. I always make sure I
have several available for each outing.
Don't make the single-point-failure
mistake of having just one memory card
available. Always have a spare at the
ready. Ensure it's been formatted and
tested so if you do fi ll up your primary
card or suffer a technical glitch, you're
still in the imaging game.
Choose a large memory card if you
expect a long astrophotography session
or plan to shoot video. For routine
The author preparing for a night of astrophotography
with his Takahashi telescope
and heavy-duty equatorial mount. Although
light pollution compromises the skies above
his central Virginia home, he still manages to
produce some very pleasing images despite
the local sky conditions.
imaging, I typically use a 32GB memory
card, but if I'm capturing a lunar eclipse
or an all-night meteor shower, I'll use a
64GB or 128GB card to be sure I don't
run out of storage.
You'll rarely get the photo you're
after on the fi rst try, but that's okay
when you SAAS and ensure you have
plenty of storage available.
3: Take What the Sky Gives
In the June installment of " First Exposure, "
Tony Puerzer discussed how to
work with just the equipment you have
on hand. The corollary to Tony's point is
my Tip #3: Take what the sky gives you.
Chances are you won't have steady seeing
conditions, perfect transparency, or
freedom from light pollution or moonlight.
You'll likely have to contend with
some combination of these factors each
and every outing. In time, you'll acquire
enough experience to be able to read
sky conditions well enough to make the
best of each clear night.
If you don't have your own observatory
and are a " set up and take down "
astrophotographer like me, watch the
weather forecast for a string of several
good nights in a row. This makes it possible
to leave your equipment set up to
maximize imaging time. But make sure
you have a good weatherproof cover
for your gear to protect it from the Sun
during daylight hours, or from a surprise
passing rain shower.
To help make my go/no-go decision
easier, I consult cleardarksky.com or
astrospheric.com. Both sites allow you
to enter a specifi c location and get a
detailed night-sky forecast that includes
 Left: This portrait of the famous Dumbbell Nebula (M27) in Vulpecula was recorded from the author's backyard using a Nikon D810a DSLR camera
and Takahashi telescope working at f/9.2 with a focal reducer. It is a single exposure of 4-minutes duration at ISO 5000. Right: The author captured
this view of the heart of the Milky Way during Sky & Telescope's 2019 Chile Total Solar Eclipse Tour from the incomparable skies of the Atacama Desert.
He used a tripod-mounted Nikon D810a camera and a 14mm f/2.8 lens for this 30-second exposure at ISO 3200.
sk yandtelescope.org * AUGUST 2021 55

http://www.cleardarksky.com http://www.astrospheric.com http://www.skyandtelescope.org

Sky & Telescope - August 2021

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