My first use of DeepSkyStacker with my new Canon EOS 600D DSLR ended up with a bit of a problem.

After opening my .CR2 RAW images, then registering and stacking them the resulting image was a tall narrow rectangle. I also noticed that the image resolution sizes shown in the image list was 1336×3516, rather than the correct size of 5184×3456.

After a bit of head scratching and Googling it turns out that the version of DSS I have (3.3.2) does not understand my Canon RAW format properly. This is because DSS decodes RAW files using the [1] DCRAW library by Dave Coffin, and version 3.3.2 of DSS is built using an older version of DCRAW.

The fix is to download the latest version of DSS 3.3.3 (which is a Beta) from the following link:-

[2] http://deepskystacker.free.fr/download/DeepSkyStacker333beta45.rar

This also meant I had to download [3] WinRAR to extract the files. The RAR file contains just 3 executables, which simply overwrite the files of the same name in the Program Files folder where DSS lives.

After restarting DSS it shows it is 3.3.3, and reading the set of files in again, they now show the correct dimensions for the RAW files and the final image result occupied the full screen properly.

I really like the tutorials and explanations of astrophotography principles at the [4] DeepSkyStacker website. They helped me understand the reasons, preparation and use of Darks, Flats, Dark-Flats and Bias/Offset images to reduce the noise in the image, and the kinds of settings I should try with the camera.

I also found this [5] Deepskystacker astrophotography tutorial to be very helpful.