Well, Avid doesn't do 1080p60. In fact, very few NLE's do. Although Avid MC has added some plug-ins, actually background converters for AVCHD editors to solve the incompatibility problem, the importing process are unbelievably slow. Here I advice you to change the 60p AVCHD from NEX 6 to a friendly editing format and import the converted video to Avid MC for further editing. Thus you won't meet any error and get a headache. Apply this a professional tool Mac AVCHD to DNxHD Converter to do the fast conversion, you will get the best quality as you need. Please trust it.
Guide: Make Sony NEX-6 MTS/M2TS files editable in Avid Media Composer on Mac
Step 1: Download and install the Mac MTS/M2TS Converter on your Mac; Launch it to import the NEX-6 MTS/M2TS files for transcoding.
Step 2: Select Avid Media Composer > Avid DNxHD(*.mov) as output format via hitting the Format bar.
Step 3: You’d better click Settings to set video size to 1920*1080, frame rate to 30fps for easy editing to get the best quality for editing and playing on Mac OS X.
Step 4: Click the Convert button to start to convert Sony NEX-6 MTS to DNxHD on Mac.
Tip: Join several MTS/M2TS files together via checking the “Merge into one” box before the conversin.
When the conversion ends, you can smoothly import Sony NEX-6 60p footage to Avid MC after you locate the output DNxHD .mov video.
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