deepsky index

Deep-sky Index .

Techniques.

Imaging deep-sky objects requires a good equatorial mount and stable drive system. With film one will make longer exposures (30 minutes to 1 hour) than with CCD cameras where a number of shorter exposures are made and then later combined.

During the exposure, accurate guiding on a star is necessary. One can do this visually with a separate guidescope or with autoguiders such as the SBIG ST-4 or STV on a guidescope or off-axis guider. Some amateurs have adapted webcams for guiding. The SBIG ST-7 through 10 and the STL series incorporate a separate guiding chip which allows guiding using the same telescope as is used to image the object. Some Starlight Xpress cameras can selfguide via the Star2000 module, the newer SXV range can be equipped with a secondary external guider.

For colour images on grayscale CCD sensors, an image has to be made trough Red, Green and Blue filters (RGB) or through Cyan, Magenta and Yellow filters (CMY). These images are later combined into a colour image. Sometimes a long exposure grayscale image is added as a Luminance layer, providing better resolution and signal.

Click here to see My Messier Album.

Other Deep-Sky objects:

22/11/1998 The Horse-head nebula.

NGC 891 : 11/10/1998 + 11/10/2001 + 15/08/2007

17/01/1999 NGC 1973.

13/02/1999 NGC 2359 (Thor's Helmet).

22/11/1998 and 29/03/2002 NGC 2392 (Eskimo nebula).

10/01/1999 Detail in the Rosette Nebula.

13/02/1999 NGC 2905.

02/05/1999 Supernova in NGC 2841.

20/08/1999 PN NGC 6543 (Cat's Eye Nebula).

28/2/2000 IC443.