Sky & Telescope - June 2022 - 62

SKETCH TEXTURE: HAPPYKANPPY / SHUTTERSTOCK.COM; HAND-DRAWN
STROKE: MADDYZ / SHUTTERSTOCK.COM
Sketching Primer
KEEP YOUR PAPER IN PLACE I used three clipboards for sketching
the Cygnus Loop at the eyepiece. Since I made four eyepiece sketches,
one clipboard did double duty. The blue tape holding down the corners
of the tracing paper templates was essential to keeping the paper flat
while sketching for whenever a breeze came up.
are 15 inches by 16 inches. While comfortable for me to hold
at the scope, you may find a different size works better.
Finished Pencil Drawing
I'll usually make a finished pencil drawing directly from my
eyepiece sketch, but the Cygnus Loop required an extra step
(see S&T: Sept. 2021, p. 28). I needed to place the separate
eyepiece sketches of all five Veils (distinct parts of the Loop)
at their correct relative sizes and positions, so I created a fullsize
template of the Loop on a 32-inch-square piece of vellum
paper at the proper scale using an art projector. This allowed
me to accurately transfer all the detail I'd recorded in my eyepiece
sketches to the finished pencil drawing. An art projector
The Benefits of Sketching
at the Eyepiece
1. The process of sketching forces your attention on an
object more intensely than any other method. Drawing
something - anything - requires your eye-brain system
to wake up and really see every detail.
2. The more sketching at the eyepiece you do, the better
you get at it, yes - but the real payoff is that you see
more. This is what makes you a better observer, and over
time you will come to see way more than you thought
possible.
3. It's gratifying to go through your notebook a year after
starting to see how your sketches have improved, and
how much more you've learned to see.
62 JUNE 2022 * SKY & TELESCOPE
OPAQUE PROJECTOR IN ACTION I projected a photo of the Cygnus
Loop onto a large piece of paper taped to a window. After lightly tracing
the outline of each Veil with a pencil, I completed the template of the
Loop. The photo that's being projected is a negative image that I found
online and printed at 5 inches by 7 inches.
displays a printed picture on a wall at more or less any scale.
After finding a negative photo of the full Cygnus Loop online,
I printed it at 5 inches by 7 inches and placed it under the
projector as shown in the photo above.
After adjusting the projector to get the proper size, I lightly
sketched the outline of the Loop on the vellum to complete
the template. Then I settled in to draw all the details from
my separate eyepiece sketches onto the template. Watching
the drawing come alive with everything I'd seen through my
scope was a wonderful experience.
The finished drawing was made with a mechanical pencil
with 0.7-mm HB lead - the same one I use at the eyepiece -
a cleaning bag, and an eraser pencil. That, and my little finger
for smudging.
Digital Rendering
Making a digital version of the finished drawing is usually as
simple as putting it in a flatbed scanner. But for drawings that
are too large, photography is the answer. Sounds easy, right?
Yes, but no. The drawing must be nearly perfectly illuminated
so there's no brightness gradient. This requires setting
up a temporary studio in order to get the lighting just right.
After what always seems like too much effort, it's then time
for some computerized image processing. Even if you have
no interest in digitizing your drawings, it's still a good idea
to scan or photograph your work - a digital backup will be
invaluable if the original ever gets damaged or lost. Plus, digital
renditions are easy to share with others.
My goal with image processing is to turn my pencil drawing
into a rendering that looks as much like what I saw in the
eyepiece as I can manage. I find this step hugely satisfying,
and it's what you see in my observing articles. I use the free
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Sky & Telescope - June 2022

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