This is a combination of 318 exposures of 15 seconds each with the camera pointing straight up. Total exposure time was ~ 1:46:02. The gaps in the ISS trail are due to image save time.
North is at the top. East is to the left. (Opposite of how a map works, because you're looking up. =P )
The ISS passed through in the first few minutes of exposure. You can also see the SKYMED 2 satellite faintly at the far right. There are also a couple of small meteors present.
I removed 4 airplanes with PhotoShop. I also used PS auto-contrast to make the blacks blacker and the brights brighter.
Camera: SX20 IS
Native Settings: Manual mode (M); ISO 80; shutter 15s; focal length 5.0mm - 28.0mm/35mm equiv.; aperture f/2.8; manual focus to infinity
CHDK Settings: Dark Frame Subtraction (DFS): off; Save as RAW (DNG): off; using default intervalometer script with interval set to zero (0) secs.
Post Processing: Averaged 5 manual dark frames; Subtracted master dark frame from each of 318 .jpgs using GIMP script (If anyone knows how to automate this in PhotoShop,
PLEASE let me know!); Removed 4 airplanes with Healing Brush and Spot Healing Brush; Combined all photos with freeware
startrails program; Ran PS Auto-Contrast on the resulting image and saved as PNG. (Converted to JPG to meet size limit here.)