Completed SAC Trackers
Antennas site is a shot of my tracker set up
at the Hovatter Road "Antennas Site" about 100 miles from central
Phoenix, west on I-10. Lots of room for plenty of people shooting the
sky. The bad news, lots of airplanes tracking through the shots, but that
is modern life for a wide field astrophotographer.
Bob Gardner and his red tracking mount on a beautiful gold
tripod. Bob was the club president years ago.

Quad_Pod is Pete Burgraaf, the designer of the SAC Tracker,
and his "QuadraPod" mount. Certainly an inventive way to get
your tracker working.

Tracker1 thru Tracker7 are different views
of Steve Coe's tracker. It is mounted on an old Celestron tripod that
I purchased at Riverside for 20 bucks. The green tape is on the switch
for choosing "North or South" so I don't reverse the motor by
mistake. I usually add a counterweight, a jug of water will work. In one
of the images you can see an old counterweight that I have also used successfully.
Gene Lucas says to let the weight just touch the ground for stability.
I will try that. The batteries are taped onto one of the legs of the tripod
and this design needs a 6 V Lantern battery and a 9V transistor battery.
Some tips:
1. Polaris is not directly on the pole, it is one degree
from the North Celestial Pole (NCP) in the direction away from Kochab,
the bright star at the end of the Little Dipper. Just set up the hinge
axis so that it has Polaris at the edge of the view through the pipe.
Make certain that Polaris is offset in a direction away from Kochab. That
is generally down in the winter and up in the summer.
2. Bring a towel or other knee pad. Kneeling on Arizona
rocks for a while getting lined up on the Pole and lining up the image
in the camera will get to your knee caps after a while.
3. Bring fresh batteries.
4. You are doing technical work in the dark. Be obvious:
make certain the gears are turning the correct direction. Don't start
an exposure when the gear needs to be reset back to the beginning of the
curved bolt. Make certain that the lens cap is off and the cable release
is opening the shutter. Put film in the camera and make certain it is
advancing. If you are using a digital camera, make certain there is room
on the capture memory card for new images. Check the f/ratio of the lens.
I leave it to you to create new ways to make an "oops"
while photographing the night sky, there are lots of ways to mess up.
But, it always seems that enough of the shots do turn out that you are
willing to try more. So, be prepared and be persistent. |