I have been doing a lot of googling to find out if someone has posted an approximate value on how much the video gets cropped on the NEX / SLT cameras. Even emailed Sony Australia but because of the current situation (Thailand flooding) and an all-out marketing campaign on the current SLT/NEX cameras, no one has gotten back to me. So I tried doing my own test using my NEX-5.
I just saw this on the manual of the NEX-5N. It is true then that what you see isn't what you get when you shoot videos using the NEX-5N. Is this a bad feature? No, it is not. I think one of the reason this is happening is to keep the aspect ration to 16:9. In fact, NEX users has the advantage of actually seeing the grid where the video would fit compared to the SLT cameras. I have friends who have tested it on their A55 and it does happen but it doesn't have any of the 'corner' markings compared to the NEX-5N.
|NEX-5N User Manual|
So, next time you are shooting videos with your NEX, be sure to check the grid first so you know that the scene you want to capture is all in the frame.