Although the native file size of the 7D image is slightly larger than the Alpha 350 exported to 17.5 megapixels - remember, these are all upscaled Alpha images, to match the 7D file size - there is not a massive difference in visible detail betweem 14.2 and 17.9 megapixels in to start with. The Canon's slightly softer image rendering even at ISO 100 has produced smaller JPEG sizes when the raw conversion (all using ACR 5.5) is saved at level 10 JPEG. I expected the Canon files to contain more detail and be physically larger data sizes than the Alpha, but they were not.