Between Midnight and 1:30 am I was able to do my first true piggyback shooting with the XSi mounted to the Celestron 9.25 Edge. I was tracking and polar alignment was pretty good for 2 minute exposures.
I began by focusing using Liveview on Arcturus. Then I moved to the Lagoon Nebula and took 10 light frames and darks. Lens was zoomed to 55mm and ISO 1600 for 2 minute exposures tracking for a total of 20 minutes.
Next I moved to Deneb and refocused in Liveview after which I took 5 lights of the North American Nebula and some darks. Lens was zoomed to 35mm and ISO 1600 for 2 minute exposures tracking for a total of 10 minutes.
Processing in DSS this morning showed the lens picked up the top of the OTA and the finder scope requiring that I crop the final picture from DSS before processing. Future piggybacking will require mounting closer to front of scope.
Other lessons learned is I need a longer USB 2.0 cable to go from camera to laptop, need to cover the laptop screen in red cellophane and provide a hood over it while imaging to reduce the effect on night vision. I also need to tie down all the cables running from the scope to my work table.
After processing, I was satisfied with these first results but saw that I should have checked focus on the Lagoon shots before taking the lights. Somehow I think the focus was a little off. I also think ISO 800 and shorter shots with more lights will improve the noise a lot. But it is a start!