Drop this tiny video camera into a telescope's eyepiece holder
and you're ready to image the Moon and planets in color.
BRING UP THE SUBJECT OF MAKING color video recordings of the Moon and
planets, and most amateur astronomers will conjure up thoughts of
holding the family camcorder to the eyepiece of a telescope. Banish such
thoughts! The new Astrovid Color PlanetCam from Adirondack Video
Astronomy (AVA) is far better than any camcorder for color imaging
through a telescope, and it looks nothing like a camcorder. Indeed,
there are eyepieces that are larger, heavier, and cost more than
Unlike a camcorder, however, Planet Cam has no onboard recording
capability. It's a high-quality color CCD camera with manual gain,
contrast, and shutter controls in a package a little bit larger than a
box of 35-millimeter film. PlanetCam's output is a standard NTSC
composite video signal, which can be viewed or recorded on a
user-supplied monitor or videocassette recorder (VCR). For imaging the
Moon and planets, its design is right on target. It's a little
camera that gives big images.
I can't imagine a telescope so small as to have balance
problems when PlanetCam is slipped into the eyepiece holder. The
camera's cube-shaped body measures about 2 inches (50 mm) on each
side and weighs 6 ounces (190 grams). The supplied 1 1/4-inch adapter
screws into C-mount threads on the camera body.
PlanetCam's 1/4-inch-format CCD has a 768-by-494 array of
slightly rectangular pixels about 5 microns across. This small chip is
the key to PlanetCam's success as a planetary imager, since it
doesn't require a telescope of long focal length to produce a large
on-screen image and reach the theoretical resolution limit of a given
aperture. The AVA Web site (www.astrovid.com) gives a simple formula for
calculating the pixel scale of a CCD imaging system:
s = 205 X p / efl
where s is the pixel size in arcseconds, p the pixel size in microns,
and efl the effective focal length of the telescope in millimeters.
There is general consensus among experienced planetary imagers that a
good pixel scale to shoot for is about 1/2 arcsecond with
black-and-white CCD cameras. This is almost exactly the pixel scale
obtained when PlanetCam is attached to an 8-inch f/10 telescope without
any additional eyepiece or Barlow projection. Color cameras, however,
have less resolution than implied by pixel size, and thus perform best
with a somewhat longer focal length.
PlanetCam is completely user-adjustable in its fundamental
image-capturing parameters, including gain, contrast (called gamma in
the world of video imaging), shutter speed, and color balance. Separate
knobs on the back of the camera body control the gain and color balance.
When you turn the color-balance knob clockwise, the image appears bluer,
while an opposite turn reddens the image. This is PlanetCam's
so-called white-balance adjustment, since there is no automatic setting.
Four small DIP switches on the back of the camera control image
sharpness and contrast. The pair labeled "aperture" actually
control the sharpness of the image. They offer four modes--soft, normal
(or unsharpened), hard, and most. Another pair labeled "gamma"
adjust the contrast, which can be set at values of 0.2, 0.45, 0.60 and
1.0. The higher numbers produce lower contrast, while the 0.2 setting
will make flat scenes snappier. The four switches are small but can be
worked with a fingernail.
Less accessible is another set of DIP switches on the top of the
camera body beneath a small cover. You reach these switches by removing
two small screws securing the cover. There are eight switches, but the
first four serve no function. The next three select shutter speeds, and
the last switch toggles the camera between a positive and negative image
(note that this is a negative color image, not a view with black stars
on a white background). There are preset shutter speeds of 1/60 and
1/1000 second and an "automatic" setting, which is a variable
speed controlled by the amount of light falling on the CCD. Most people
will need a magnifier to read the numbers on these tiny switches. A
small jeweler's screwdriver works well for changing their settings.
The product shown is the exact item up for sale. Please email us any questions you may have concerning this listing.
Why Buy Your Next Telescope from CCTS?
1. CCTS Quality Control
Every product we receive is physically and optically
inspected by our experts for proper collimation and flawless operation. We
take the time to make sure that the product you receive is the best
instrument you can get.
2. Customer Support
At CCTS, the
owners, Jeff and Greta, take a hands-on approach to customer service. They
will personally make sure that your order is filled promptly and
courteously. You will NEVER feel that your hard earned money is spent
unwisely with a company that is too busy to take the time to see that you
are serviced well.
3. The Best Extended Warranty in the
CCTS provides customers with an elite level of service
unlike any other company. Purchasing an Extended Service Contract from us
means that you making an intelligent investment in the future of your
We offer the most comprehensive AND the lowest priced
warranties in the business:
How about a 3 year extended warranty for only $49.95 on
a $2000.00 telescope or camera?
None of our competitors even OFFER extended warranties!
Protection for your equipment after the manufacturer's
warranty expires. AND...
You can transfer the contract to a new owner!
AND... OF COURSE... LASTLY:
4. We are Never Undersold!
Filed under: Eyepieces & Accessories