SBIG ST-4K, 1800s total exposure 10/3/13 Lake San Antonio, CA
This was an attempt to get a much deeper exposure of this famous supernova remnant in Taurus. While we succeeded in improving the signal-to-noise ratio, the focus is not quite as sharp as is in our original attempt. The 'nonlinear' version allows the outermost structure to be seen. Visually, the surface brightness is low, and I could see only a diffuse glow and not the filaments.
Starshoot DSCI, 13 exposures, 30s each 9/25/08 Lake San Antonio, CA
This is the famous supernova remnant in Taurus. The surface brightness is rather low, and it is difficult to see any structure visually. This object could benefit from more (or longer) exposures, but already the main features (red filaments and green/gray diffuse glow) are apparent.
53 exposures, 10s each 9/25/08
Here is another Crab Nebula image, obtained using 10s exposures. It looks similar to the 30s image, but the background noise is a bit worse.