Here's another Eagle Nebula. Took this late last night. You can also see the serpant on the topleft 7 x 169 second exposure stacked in registax. Processed in Photoshop CS. Darks auto subtracted.
I don't see any sign of coma in this pic - the DSI has a very small sensor so I don't think coma is an issue. If you were going to do wide fields with a DSLR I think you would need a coma corrector as the sensor is so much bigger.