Audio remains an underdeveloped feature on most DSLRs -- DSLR shooters must resort to independent recorders or pre-amp devices plugged into their cameras. However, with each new model we see (small) steps in the right direction. We have yet to see a DSLR (even at the high end) that provides direct XLR inputs, but we do now have some basic control over gain levels along with headphone monitoring. While providing a comparison of the the 5DmkIII and D800's audio features, juicedLink's Robert Rozak presents his latest pre-amp device, the RM333, and how it builds off of these new features:
Here's his comparison of the two units along with his intro to the juicedLink RM333 pre-amp:
Video is no longer available: www.youtube.com/watch?v=5knI6EnRaPk
If you're new to DSLR shooting, and wondering what the purpose of a pre-amp device is, check out the audio section in the DSLR Cinematography Guide. These devices allow you to use XLR inputs along with higher quality pre-amps to record solid audio directly into your camera(rather than recording separately and synching afterwards). As pointed out in that chapter, when trying to record sound directly into older DSLR models like the 5DmkII, you sometimes had to find ways to disable built in camera features like automatic gain control. With these newer models that offer direct control over gain, you no longer have to worry about it, and with the ability to monitor on camera, it really frees up the pre-amp device to offer the basic necessary features (and thus be as small and unobtrusive as possible).
Ideally we would be able to have these controls and inputs directly in-camera, but for now we can be moderately satisfied that things are moving in the right direction and making these accessories more and more streamlined.