skyandtelescope.org • JUNE 2020 67
objects were, big and beautiful. That night convinced me
video was the cure for my observing blues.
Getting Video Eyes
There was more to that camera than just sensitivity. Normal
video cameras only expose for^11 / 3030 second — far too brief to
pull in dim targets. By the late 1990s, however, manufac-
turers had broken through the^1 / 3030 -second barrier, and as
the decade ended several astronomy-oriented companies
were offering video cameras that could expose for as long as
15 seconds per video frame.
So, what kind of equipment do you need to get started in
2020? An astronomical video camera, of course, and unlike
the 1990s, today you can choose from models that produce
analog video or those that generate digital data. Digital cam-
eras are more versatile and allow for easy interfacing with a
computer. However, I believe it’s still best to begin with an
analog camera if your main goal is to see detail in deep-sky
objects. In my experience, analog cameras are still more sen-
sitive than their digital counterparts.
An analog camera can also be economical. The Revolution
Imager (revolutionimager.com), for example, is a complete
kit that includes a color CCD camera, small monitor, remote
control, 0.5× focal reducer, battery power pack, cables, and a
telescope adapter — all for less than $300.
I’ve tested one of the Revolution Imager kits, and while the
camera’s maximum exposure is only a little more than 5 sec-
onds, it’s quite sensitive and capable of easily showing more
than can be seen with an eyepiece. I was amazed when the
faint Horsehead Nebula in Orion showed up on the monitor
despite the distinctly average skies over my backyard.
If you want to go à la carte, the main source of stand-
alone astronomical video cameras is the Canadian company
MallinCam (mallincam.net). While it offer a full line of
digital models, it continues to sell analog units, including
one I’ve used for years, the MallinCam Xtreme. Not only does
it offer unlimited exposure times, its larger chip (compared
to one found in the Revolution) makes framing objects easier.
The video sensor is also cooled to reduce the effects of ther-
mal noise. MallinCam’s package includes cables, power sup-
ply, and a telescope adapter, but no monitor. While the cost
for the Xtreme is about $1,300, that’s still less than many
dedicated astronomical cameras.
If you need to purchase a monitor for your chosen setup,
be sure to pick one that’s capable of displaying analog video.
Most camera models output composite analog video, and
while digital HDMI is the current video standard, many TVs
and some monitors still feature analog inputs.
Even expensive video cameras have relatively small chips
compared to DSLRs or astronomical CCD cameras. That’s
why it’s vital to use a telescope with a short focal length to
ensure the fi eld of view is large enough to include a range of
deep-sky objects. I’ve found 600 to 800 mm is a good focal
length for most video work. I use an f/3.3 focal reducer with
my 8-inch Schmidt-Cassegrain telescope (SCT) to bring its
2,000-mm focal length down to 660 mm — perfect for video.
Suitable focal reducers are easy to fi nd and often inexpen-
sive. Because video detectors are quite small, the reducer’sqPACKAGE DEAL The economical Revolution Imager kit includes a
color monitor, battery pack, color long-exposure video camera, focal
reducer, cables, and remote control.uWIRED FOR VIDEO A Go To telescope with video imaging equipment
requires plenty of power and a seemingly endless number of cables and
connections. A methodical approach during setup pays dividends when
it comes to troubleshooting problems, should they occur.