Bruce Dorn found this on our sister site ProPhoto Coalition. Here’s the beginning:

If you’ve been following the maturation of the Canon 5D MKII as an HD video capture device, then you’ve probably heard about the camera’s limitations with regards to audio recording.

Yes, the 5D MKII does record audio via an internal microphone but that feature is so basic as to be nearly useless. There is, thankfully, an “Audio In” jack but the camera’s compact form-factor has necessitated that this input be the tiny and sometimes unreliable 3.5mm mini-jack. Most professional level audiophiles would much prefer the industry-standard XLR jacks but there just wasn’t enough room for these larger connectors.