The B33, M42, M78 region in Orion is full of dust and other interesting stuff.
http://www.astropix.com/B33_M42_M78.html
Click on the link to see a larger version with more information.
Some of this dust is very faint so it requires a very long total integration time to record. At the same time, M42, the Orion nebula, is very bright and saturates to white in a long exposure.
Because of this tremendous range of brightness, a special high-dynamic range technique had to be used with long exposures recording the faint stuff, and short exposures recording the bright stuff. The different exposures were then composited together with layer masks in Photoshop.
This was shot with an unmodified Nikon D5300 and an IDAS LPS filter with a Nikkor 180mm f/2.8ED AIS lens working at f/3.46 with more than 300 minutes of exposure from a mag 20.7 observing site.
Yes, you can shoot faint stuff with a DSLR, but you really have to use a lot of exposure, especially for hydrogen-alpha emission with an unmodified camera.
Jerry
