Sound is one of the main problems in using DSLRs for professional filmmaking. There are no XLR audio inputs and manual control over audio levels (if available at all) is often buried in menus. Sync sound is no so important in commercials and promos but in documentary it is as vital to capture clear audio on location as it is images.
I have been using the Canon 5Dmk3 increasingly in my professional documentary practice. The incredible work done by the Magic Lantern project has given the Canon DSLRs a set of tools that makes them more practical as movie cameras. Its most useful features for me are zebras for exposure highlights, focus peaking and “magic zoom” expanded focus while recording.
Some things, like sound, can’t be fixed with firmware hacks and so I recently tried using a Zoom H6 with the 5D for sit-down interviews. The latest Zoom can record up to 6 separate tracks of audio to a micro SD card – I usually just use two, a shotgun mic and a lavalier. Of course the prospect of having to sync the rushes in post is not one I relish, even though FCP X does a decent job of automating the process.
I was happy to find that the latest firmware update of the H6 allows you to reduce the line output level of the H6 to something close to a mic level for input to a camera. What this means is that the Zoom attached to the camera rig becomes a kind of audio mixer, with the amazing added benefit of recording the tracks separately (AND with a backup recording at 12dB lower). I found the sound was great. In most cases, it was fine as recorded on the camera through the Zoom but having the WAVs recorded at 48k on the Zoom itself was a great result. I’d recommend leaving the audio recording throughout since a 32 gb card seems to be able to store more than 8 hours of audio and its easy to forget to hit stop/start on the Zoom as well as the camera otherwise.
I have yet to try it on an actuality shoot, but my first experience with the H6 has been great.