-Objective: Braving record-length drives and endurance style sleep deprivation in search of dark skies.
-Equipment: Setup is based on a Celestron Newtonian telescope with an 8" reflecting mirror. Auxiliary equipment includes a motorized equatorial mount for the telescope, an auto-guider system (not quite running yet), various eye-pieces for viewing magnification, as well as hordes of adapters and eyepieces.
-Cameras: Canon 20D with IR filter conversion, Canon 450D unmodified.
-Software: Photoshop, Deep Sky Stacker.
-Techniques: Ordinary tripod shots, long exposures on the tripod, through the telescope, piggybacking, and time lapses.
Ordinary Tripod Shots
These are taken using a camera set on an ordinary tripod. In some cases, the pictures were 'stacked' using Deep Sky Stacker in order to improve signal-to-noise ratio.
Tripod Long Exposures
Using 'bulb' mode on the camera, badass pictures can be taken over long periods of time simply using a tripod. Most of these translate into 'star trail' pics, but others chronicle the movement of people and lights.
Through the Telescope
Using the Canon bayonet adapter (see telescope accessory page), we are able to essentially use the telescope as an ordinary camera lens. There are difficulties associated with this. For instance, the target, such as a distant galaxy, is very dark and requires a relatively long exposure in order to capture enough signal. Ideally, you would take an exposure which is many minutes long! Unfortunately, the exposure length is limited by the ability for your telescope's motorized mounting to accurately track the movement of the stars. By eye, the object may not appear to drift from the center of the telescope's frame, but during the coarse of a couple minutes, there is usually enough drifting to cause bluriness or trailing in the picture.
Most of our exposures when using the telescope are between one and two minutes. Traditionally, if it seems worthy, we'll take several pictures of the same object, and at the same settings. A cheap intervalometer works well for this. With 10-20 pictures, we use a software known as Deep Star Stacker (Google it) in order to 'combine the pictures' into a single picture with greatly improved signal-to-noise ratio. This can take a great picture and make it incredible -- probably the most powerful technique we've adopted yet.
All pictures are taken at 1600 ISO, and are generally the result of stacking, and additional photoshop work. We are currently taking steps towards extending our exposure up from our current two-minute maximum.
When the telescope isn't being used as a camera lens, but the camera is somehow fixed to the telescope and taking advantage of the motorized tracking mount, the term is 'piggybacking.' Using ordinary camera lenses, a long exposure no longer creates star trails, but rather tracks the sky almost perfectly. This allows for very long exposures which can be used to capture constellations, or the entire milky way.