There is obviously a need to use external audio recorders when you need to record more than two channels or when you need the absolute highest quality sound.
However, for most situations, recording directly to the camera is far simpler and will result in very high quality audio. This is especially true when only voices are recorded.
I think there is a myth out there that you cannot record quality audio to any DSLR camera – this is simply not true. We get calls every day from people who have quickly tired of the need to record audio separately and are then faced with the issue of having to sync everything in post. Most people are surprised at how good the in-camera audio can be once everything is set up correctly.
Since the camera’s preamplifiers are relatively noisy at high gain, the key to clean audio is in reducing the gain as much as possible. The lower the gain, the lower the noise. You can then use a low noise external preamplifier, such as the one built- into our popular DXA-SLR ULTRA, to provide clean gain to the camera. This will result in a very high signal to noise ratio, comparable to a typical external digital audio recorder.
It’s also very important to record at the proper levels. Too high and you will cause clipping and distortion, too low and you’ll be close to the noise floor and will pick up excessive hiss. A recording level of around -12dBFS on the VU meter is the sweet spot for the best signal-to-noise ratio, so having one of these devices is a must.
Cameras are getting better at recording audio all the time. When the Canon EOS 5D Mark II first came out it was a real challenge to record good audio on it. It had an awful AGC circuit, which would pump up the noise of the preamps on every quiet spot, no VU meters to check levels, no headphone jack to monitor audio and a limited frequency “Most people are surprised at how good the in-camera audio can be once everything is set up correctly” response. Now with cameras like the Panasonic GH4, which have full manual audio controls, limiters, VU meters, headphone monitoring and an excellent frequency response for wide bandwidth sound, it’s very easy to record professional audio directly to the camera. Best of all – no syncing is required! We’re all about simplicity. We make things easy for users to get great audio on their camcorder or DSLR, and that’s what audio adapters are all about.