› ›kelbyone.com081‹ ‹ PHOTOGRAPHY SECRETSSaturn: Nikon D3S, Celestron NexStar 8SE telescope, and TeleVue 5x Powermate.
Ninety images @ ISO 800, f/10, and 1/2.5 to 1/6.
Star field: 17–35mm lens @ f/2.8, ISO 3200, f/2.8, and 25 seconds.Wide-field image of the nebulae in the Orion constellation.
Orion’s Belt is the diagonal line formed by the three blue stars
on the left, ending with the blue star in the center nebula.My imaging telescopes. Left: Celestron NexStar 8" SCT with Alt-Az go-to mount; Center: Takahashi TSA-102 4" refractor with Celestron
CGEM equatorial mount; Right: Astro-Tech 12" Ritchey-Chrétien truss tube telescope with Takahashi EM-400 equatorial mount.DEEP SPACE: THE FINAL FRONTIER
For deep-sky targets, such as nebulae and gal-
axies, a motorized mount is a must. There are
two types: Altitude-Azimuth mounts (Alt-Az) and
German Equatorial mounts (GEM). The GEM is
the best choice for astrophotography. Once the
mount is polar-aligned, lengthy exposures can
be taken without any target movement. Expect
to pay $500–$1,500 for a quality GEM that can
handle a DSLR with long lenses and/or many tele-
scopes. To ensure smooth operation while imag-
ing, the mount’s rated weight capacity must be
twice the weight of the equipment you intend to
use, so purchase wisely.
Learning To Walk
Deciding how to shoot deep-sky targets will deter-
mine equipment selection that will, in turn, dictate
the size, quality, and detail of the targets being
imaged. Wide-field images can be captured with a
DSLR, a modestly priced 80mm (3") refractor tele-
scope, and a Celestron Advanced VX GEM mount
(30-lb load capacity). Not counting the camera,
your investment would run approximately $1,500–
$2,000 by the time you add desirable accessories
such as dew heaters and an autoguider.
This photo (right) is an example of what’s pos-
sible with this setup, including the accessories. I
shot a total of 160 images at various shutter speeds
ranging from 10–45 seconds at ISO 1600, and 10
images with 1–3 minute exposures to layer in a sky