Sky & Telescope - April 2021 - 56

APRIL 2021 OBSERVING
First Exposure

and ImagesPlus are just some of the
other software packages that, in the
right hands, can produce spectacular
deep-sky images. Luckily, a good set
of image data never goes bad. You can
return to it time and again as your
processing skills improve. I've gone back
to older images and have been pleasantly surprised at how my results have
improved with practice. The main thing
is to do your homework, pick one piece
of software, and stick with it so that
you master its capabilities.
Digital imaging unavoidably generates a lot of data. Don't underestimate
how much storage space your new
hobby will consume. With so many
image ﬁles, it's very helpful to develop a
consistent format for naming and organizing your data folders. A little effort
up front will make it easier years from
now to retrieve and work with your collection of older images.
With my setup, the archive for a
single ﬁnal image can consume up to
50 GB of disk space. That's why I have a
hard drive dedicated to astrophotography only. I give each imaging project a
folder named with the format: ObjectFilters-Month-Year (e.g. M57-HaRGBSept-2020). Within that folder I make
subfolders for the different types of
image data, be it " light " frames or " calibration " images. I also include a text ﬁle
containing basic information about the
equipment I used, exposure times, and
date(s) of acquisition.

Strategic Thinking
They say patience is a virtue, but as
a new astrophotographer I wanted
to shoot everything, and right away! I
would photograph up to ﬁve different
objects in a single night. Now I'm more
interested in quality over quantity. Give
me one great shot of the Heart and
Soul Nebula (IC 1805 and 1848) over a
set of mediocre images of a half-dozen
different deep-sky objects. I tend to
spend several nights on each target,
56

APRIL 2 021 * SK Y & TELESCOPE

S Sometimes it's a treat to indulge in some imaging " fast food. " You can often capture open clusters and dark nebulae in just a single night. This image of Barnard's E (B142 and B143) required
just a few hours of exposure time.

and I choose objects that transit near
local midnight, when they're highest and least affected by atmospheric
conditions. On long winter nights when
it's dark from about 6 p.m. to 6 a.m., I
might shoot two targets: one that transits around 9 p.m., and another that's
highest around 3 a.m. On short summer nights, I typically have to spend
multiple nights on a single target.
Great nights when everything goes
right can feel like a rare prize. That's
why you don't want to be adjusting
your equipment while the stars shine
invitingly overhead. I prefer to use hazy
or moonlit nights for those inevitable
maintenance tasks. You can also make
productive use of sub-par nights to test
out your equipment. For example, it's
useful to know how long an unguided
exposure you can take and still obtain

round stars, or ﬁgure out the size of
your setup's properly corrected image
circle. It's also handy to know how
often you need to refocus as the temperature drops during the night. Knowing these things can help you make the
most of your time when a really good
night comes along.
Astrophotography requires a lot of
different skills and a daunting number
of things have to go right at the same
time to achieve the ﬁnest results. Luckily, there are lots of Old Men like me
willing to share our experiences. Maybe
with the beneﬁt of this hindsight, you'll
bring back more astrophotography gold
than I did when I started!
RON BRECHER has been imaging the
sky for more than 20 years and is still
learning about astrophotography.

Sky & Telescope - April 2021

Table of Contents for the Digital Edition of Sky & Telescope - April 2021