Dark Frame tests using the Canon 300D Digital Rebel

These Dark Frame tests are indicative of the noise to be expected from the sensor at exposure times of 5 and 10 minutes over the full ISO range of the sensor.  Images as displayed below are high quality jpg 200x150 pixel crops from the center of the original full-sized images.  Right Click/Save As... on the images if you wish to examine TIFF format files (175k file size).  Ambient temperature for the test was 21°C, so these results should represent close to the worse-case for noise.   All Dark Frames were taken with the lens cap on.

The Statistics are computed by ImagesPlus from TIFF 16 bit files, converted from the original Canon Raw format 12 bit image files. 

The full ISO range 100 to 1600 is covered, and two groups of tests were performed at 5 and 10 minutes exposure time.

My Conclusion: Good results can be achieved using the Canon 300D Digital Rebel for astrophotography purposes using a 5 minute exposure and up to ISO 800, or using a 10 minute exposure and up to ISO 400.  Subtracting dark frames from images of celestial objects will produce excellent resulting astronomical images.