|
A
video camera of 80s vintage.
|
A
modern ultra-sensitive surveillance camera works great for astronomy.
The camera is dwarfed by the 50mm focus assembly! |
Originally
we did some experiments with a reasonably old video camera (above left)
as it has a 50mm aperture lens instead of the smaller ones that prevail
nowdays. Despite its bulk it was, for some reason, easier to mount to
the telescope than any other camera that we tried. This is not really
the ideal setup for attaching a camera to a telescope since the
telescope is effectively a giant lens anyway and should be usable
without projecting the telescope's image onto the camera's own lens.
A domestic video camera is actually
not that great for astronomy
because they are not really sensitive enough for anything except the
moon and some planets. |
We have been
experementing with ultra low light surveilance cameras that usually use
Sony's HAD
technology. As well as being able to record occultation events this
will also be very handy for "looking" through the telescope from across
the network. Using this camera we can easily record stars at 10th
magnitude and is usable down to 12th while maintaining a 50
field/second rate.
See
some work we have done with this camera. |
To
be useful, video astronomy needs a good on-screen time reference in
order to time events. To do this we use our GPS clock (below right and here
), and generate a video on-screen display (OSD) with the UTC date and
time to millisecond precision. The OSD board can be seen below left and
its display on the 4" monitor. The simplicity of the board doesn't hide
anything at all - OSD is as simple as a video sync separator and a
microcontroller.
Practical uses of this can be seen on our science
page |
GPS video
timingstamper. The text near the bottom of the screen is overlayed onto
the video by the microcontroller on the PCB. |
The GPS clock is at the top of
the left pole (the other thing is a rain gauge).
|
