As advanced DSLR video technology becomes cheaper and cheaper, the idea of using a DSLR camera such as the Canon 5D Mark III to shoot professional video is quickly becoming a reality. Documentaries, commercials, and even feature films are beginning to embrace DSLR as the recording platform of choice.
Consumer solutions including the Canon Rebel T3i, Nikon D90, and others are opening doors for amateur videographers to create stunning videos on a shoestring budget. The one thing all of these cameras have in common is terrible audio.
No really, your $3,000 DSLR has a terrible microphone on it. I’m sorry, but you’re not paying for audio recording on a DSLR, and you will probably be waiting a very long time if you’re holding out for one that has a decent microphone built right in.
Here’s the deal: The microphone supplied with a DSLR is best used as a reference tool rather than an actual recording device. Below are some tips I’ve come across to help you improve how audio is recorded with a DSLR.
Magic Lantern is a free software tool that you can install on 550D, 60D, 600D, 500D, 50D, and 5D Mark III DSLR cameras. This firmware overlay (not actually a firmware replacement) adds some incredible features to many of the more popular DSLR cameras out there for video recording including a built-in automatic gain control (AGC) override.
DSLRs are notorious for having automatic gain control baked in to the firmware in a way that doesn’t allow you any actual control over how much gain is applied to your audio track. The Canon Rebel T2i is one of these devices, and for the most part recording audio through it is a nightmare, even with external microphones. If you throw Magic Lantern on, the AGC can be turned off which enables you to grab audio as it should be recorded from your microphone without the noise and hiss commonly associated with overdriven amplifiers.
I use a T3i, and while the camera does give me the ability to manually control the built-in gain, there is a sweet spot around about 5% gain and +20 db on the microphone that makes subjects 5-10 feet away sound fantastic. You have to fiddle around with your particular mic/camera combo to find the best recording settings for you, but the best setting usually doesn’t include cranking up the gain on your DSLR.
As I said earlier, recording audio from your on-board microphone should only be done as a point of reference as opposed to a primary audio source. Most DSLRs these days with HD recording capabilities come with a hot shoe that can be used to mount a shotgun microphone such as a R0de VideoMic Pro. The hotshoe itself doesn’t need to power anything on most external mics as these are typically powered by their own batteries, but the option is there should you find one that does allow the mic to share battery life with your camera.
Having an external microphone plugged in through the mini jack gives you the ability to provide good, clean audio to your video recording in a way that doesn’t require syncing them up later on. Everything is kept in one neat package for easy editing.
It’s very easy to fall into the cheap microphone trap. Low-cost and budget wireless lavaliere microphones are especially prone to screwing up a perfectly good recording, and you generally won’t discover these issues until it is too late. The same can be said for those really low-cost wired microphones that look like they could be a great way to save money and get close sound, but the reality is a hiss-ridden mess that is almost impossible to clean up in post. Not all DSLRs allow you to monitor audio through headphones, either. This brings me to my next suggestion.
Having a good, independent audio track recording apart from your video can be a very good thing. Dedicated audio editing software is typically a lot better at mastering audio for production purposes than any video editing software could be. In addition, a good audio recorder will enable you to grab multiple tracks and mix them into a single data file for easy editing, storage, and management.
A lot of professional video producers use devices such as the Zoom H4n to grab audio separate from video. These devices enable you to use an external microphone or rely on the above-average built-in microphones mounted on the device itself to capture clean audio during shooting. Even with the built-in microphones (of which many good audio recorders should have two) the audio is certain to be better than anything you could grab with the standard on-board DSLR audio tools.
Think about it this way. A better source means a better result in almost every situation. If you could choose between the DSLR firmware that rarely gives you more control than a simple volume setting or a dedicated audio device that gives you multi-track recording and plenty of amplification options, which would it be?
Use your camera’s on-board audio as a reference to help you sync the tracks. Make a loud noise by clapping your hands. This will create a visual spike on both your camera and external mic’s audio track that you can sync up before deleting the camera’s audio and linking your better source.
If anything, having two recordings of a single situation is better than one. Never underestimate the power of backups.
Boom Vs. Lavaliere Vs. Camera Mounting
Now that you’ve decided to get off the onboard audio in favor of an external or independent audio source, how do you mic it? Do you go with a boom microphone suspended above your subject, a lavaliere mic clipped to their lapel, or a shotgun mic mounted to the camera itself? To put it simply, it depends on how you’re using it.
A boom mic is a great solution for situations where you need to mic multiple people in close proximity to each other without having to deal with the directional sensitivity of a front-mounted shotgun camera or the need to multiple cables and mics with a lavaliere shoot. Booms also allow you to concentrate your audio on your subject and not on the things that might be behind them, making it easier to have a good, solid recording.
Lavaliere microphones have the advantage of being less sensitive to wind and other environmental conditions. A good wireless or decent wired mic will produce clear sound that drops off considerably beyond the individual’s own voice. In a sense, a lavaliere gives you the ability to make even outdoors shooting sound like you’re in a studio. The downsides with lavaliere microphones present themselves when the individual being filmed does a lot of fiddling with clothing and waves their arms around. It’s easy to smack, slap, or rub a lavaliere microphone which could ruin a recording.
Camera-mounted shotgun mics are a favorite among reporters and independent video producers. It enables you to capture just about anything going on directly in front of the camera, which makes it a great profile solution for solo shots as well as some interviews when the interviewer and interviewee are standing in close proximity. You have to be careful with this type of shooting, especially if you opt to avoid the tripod and hold the camera yourself. Vibrations can cause issues with your audio, background noises will present themselves more often than you’d like, and the host doing so much as turning away for a second during their presentation can add a muffled and even muted effect when you least want it.
Bottom line: Do what you feel most comfortable with. A good microphone will provide you a variety of solutions. The Rode VideoMic Pro, for example, can be mounted on the DSLR camera as well as a boom pole. This versatility will make life much easier for you while improving your overall audio quality.