Mountain Lion doesn't accept DSC RX100 AVCHD files

With the HX9V and NEX-5 I find the easiest way to get video files on to the Mac is to put the SD card into my MBP then use the search bar to look for .mts then normally use Clipwrap to place my file into an .mov wrapper before editing on iMovie.

For quickness, I sometimes just use iSysoft iMedia Converter to perform simple video authoring straight from .mts files.

Seems to get the job done