Astro-Photography
Tripod Mounted
The simplist form of astrophotography is done with a camera and tripod,
and a collection of quality lenses. The camera must have the capability
of locking the shutter open for a few seconds so that the very low levels
of light have time to "accumulate" on the film. Tripod mounted
cameras are limited to relatively short exposures of 15 seconds or less
and a lens of no more than 100mm focal length is recommended as the stars
will begin to trail due to the Earths rotation.
Piggyback
This method requires a bracket for mounting your camera on top of your
scope. If your scope has a motor drive the procedure is easy. Swing the
scope to your target, focus at infinity, turn on the drive, open the shutter
with a cable release and lock it open. Wait ten minutes and release the
shutter. Use ISO 400 or 800 as this will allow fainter stars to be recorded
in a short period of time.
Prime Focus
The lens of the camera is removed and the camera is attached indirectly
to the main optical tube where the telescopes' optics are now the lens
of the camera. A couple of special adapters are required:- (1) a T-adapter
and (2) a T-ring, obtained to fit your camera model. Once attached to
the telescope you now have a "high power" camera lens of 700mm
to 2500mm or more depending on your particular scope
Eyepiece Projection
This involves the use of an eyepiece projection tube that is similar to
a T-adapter. An eyepiece is inserted between the scope and camera to magnify
the images going to the camera. This will allow focal lengths of 15,000mm
and more!
A DSLR camera using a T Adapter at prime focus
Webcam Astrophotography
Astro webcamming raised amateur imaging to an amazing level of quality.
The common use of nonmodified webcams are planetary, lunar and solar imaging
and double stars. Webcam hardware can be modified to long exposure times
giving good results for DSOs like nebulae and galaxies. Usually the webcam
is inserted into the prime focus of the telescope instead of an eyepiece.
Adapters that can be screwed into the 12M X 0.5 thread of a ToUcam are
available, selfmade adapters made from a 35mm film canister are an alternative.
Often the webcam is used in conjunction with a barlow lens for extended
magnification.
For more detailed information about astronomy equipment post your queries on our message board.