You don't say when the shimmer occurs, and this could be important. I don't mean in the panning itself, but whether you are talking about the raw footage, or after you have edited it and created a new file or burned some sort of disc (Bluu-Ray, AVCHD hybrid disc or even standard definition DVD...)
But first, shimmer is very common with high definition cameras, both AVCHD like yours or HDV. Some say that AVCHD cameras are worse than HDV for this, but my eyes are not good enough to notice much difference between the two: it is all awful. The simple answer is not to pan very fast and not over a very wide angle. If you every see any professional HD footage, you will see that they prefer to let the camera sit mostly still, and have leaves waving or people or cars moving to give the idea of motion. If they pan, it is done verrrrrrry slowly and only over a few degrees.
I am talking about horizontal (left to right or right to left) panning. The shimmer does not seem to occur when doing vertical panning.
Now the other reason you could be getting shimmer relates to my first question. Your camera, when shooting interlaced video, uses Upper Field First as the field order. And this must be maintained throughout the project, including in the final video you produce (and burn to disc). If for some reason, Upper Field First gets converted into Lower Field First, then you will also get shimmer in horizontal pans, and what they call 'jaggies' -- jagged edges on vertical lines like the edge of buildings, light poles etc.
But I suspect you are getting the fast pan shimmers...!
