I had a mishap with my 7D while cleaning the sensor and it is now scratched, well what I believe to be the AA filter is scratched. Is the AA filter removable/replaceable? I am extremely happy and always have been with my 7D's image quality and I am a little anxious that a new sensor will bring the image quality down. I have been told by a well known repairer that this isn't the case, that I would have to replace the whole sensor+filter pack, but from what I see from your photo sets, it seems to be that you can replace just the filters. Am I right? Thank you so much in advance.