Whether it involves a sit-down interview or capturing an unexpected moment while following a subject around, you have to be as mindful of the documentary audio as much as the framing of the shot…unless you want to experience that painful moment when you realize you failed to capture that quote on camera. Here are ten potential mistakes you should avoid when shooting a documentary.
10 Documentary Audio Mistakes to Avoid While Filming:
1. Make sure you are holding that boom mic comfortably and still
Holding the boom mic is an effort on to itself. One can grow tired very quickly without positioning it in just the right way, especially when it feels heavier the longer one holds it. Make sure your hands are spaced about a foot apart while gripping the pole. This avoids the impulse to shuffle one’s hands along it which will be picked up on the microphone and, therefore, can ruin your recording.
Make sure the microphone is pointed down towards the sound source. And try holding the boom pole somewhere around the middle so that you can balance the weight. You may also rest the pole along the back of your neck if you want but make sure you’re well adjusted before the camera starts rolling.
2. Do not record audio directly from your camera
Or at least do not use the on-camera mic. Or, rather, the internal mic. The one that’s already built into your cam, that is. That doesn’t mean that you should never record audio directly into the cam should you be using a wireless receiver or an attachable shotgun. But it would be wise to not depend on that only. Always have an external recorder handy (like the Zoom H4N or H6, for example). And record additional audio for your documentary from there. That way if something should happen to your footage (heaven forbid) you always have that external track to depend on.
3. Make sure the microphone and wireless receiver are set to the same channel
It is an easy mistake to make while under pressure (having to quickly mic a subject with a wireless lav or boom mic that wirelessly connects to a recorder when under run-and-gun situations). Simply, remember to make sure both the mic and receiver are set to the same channel. And if they aren’t… no audio recording for you.
4. Do not place lavaliers too close to the mouth
This is something I’ve come across on many a shoot. You’re videotaping a talking head interview and, therefore, need to attach a lavalier microphone to your subject. When placing the mic too close to the mouth (say, clipping it to the top of the shirt just at the nape of the neck), you run the risk of picking up too much breath, possible wheezing and, heaven forbid, should your subject cough or is a habitual grumbler (it happens), all of that is picked up on the mic. And it picks up really loud! Keep the lav positioned somewhere between the chest and just below the neck. And you should be good to go.
Also: don’t be too concerned with hiding the lav underneath a jacket lapel, vest or sweater. If you try to hide it too much, you increase the risk of recording clothing rustle against the mic.
5. You get what you pay for
Unfortunately, there is no truer sentiment when it comes to audio recording equipment. The more you spend on a microphone, the better the quality. The less you spend… chances are you purchased yourself a fairly subpar piece of gear. Expect to spend at least $500 on a decent wireless lav system, for example.
6. Use your headphones and don’t just rely on the meter
Every audio recording device has a digital meter. This allows one to adjust the level of sound being picked up by the microphone. However, you should not depend on the meter along. Use your headphones. Actually gauge aurally how the tenor of your subject’s voice can change throughout the interview so you can adjust accordingly.
As for setting your meter, make sure the level rests between -12 and -24. Anything higher can result in some screechy, hard-to-fix-in-post sound. Especially when your subject raises his or her voice, laughs, or coughs. Anything lower sounds, well, too low.
7. Always record room tone
This is quite possibly the most easily forgotten task when it comes to recording audio on a documentary shoot, especially while producing a documentary. But it is an imperative step when recording sound for post-production purposes. Room tone acts the “bed” the rest of your audio tracks rest on when editing down an interview captured on camera. It offers a smother transition from cut to cut. Without it, it can be very challenging for your editor to pull those clips together without any jarring audio changes or skips.
8. Background noise
Avoiding background noise while shooting outdoors can be an almost impossible task, especially when your recording your subject in a populated area like a park or city street. While it’s best to not use those locations as much as possible, sometimes things are easier said than done. However, there are sounds a mic can easily pick up that are not initially noticed by the human ear. Like the fan of an air conditioning unit, for example. Or the low hum of an old refridgerator. When setting your audio levels, take that extra step of listening for nuisance noises like this. Then shut off or unplug the culprit. Sure, this may result in a very uncomfortable interior shoot on a hot summer day. But at least the recorded audio will sound perfect for your documentary.
9. Batteries, batteries, batteries
There is no such thing as too many batteries. Wireless receivers and external recorders take up a lot – and I mean a lot – of battery juice. So have at least three packets of AA, AAA, or whatever “A” batteries that are required to power your gear. And make sure that you always have three of each.
10. Remove cell phones and keep ‘em far away from the mics and receivers
Cell phones – smart or not – can cause interference to the signal moving back and forth between the receiver and your wireless mic. So… shut ‘em off and keep them far away by at least a few feet.
Why is good audio important in a documentary?
Audiences have a much higher threshold for visual errors than for bad audio. If your audience is struggling to understand the dialogue, they will get immediately frustrated as their understanding of what is going on is more strongly tied to the words being spoken. If the focus is a bit off or the composition isn’t quite great, people will generally tolerate that more if the story is compelling enough.
When you have good audio, the documentary audience feels more connected to the story. They are more engaged and following the characters. They hear the ambience of the environment, are moved by the music if present. Good sound is almost invisible. People get impacted by the effect of it without realizing it is happening. It is only when it is done poorly that it is noticed.
What to do if you make a mistake recording audio?
While some audio mistakes can be nearly catastrophic to the documentary, small errors can be corrected. If you happened to record the sound too quietly, you can apply gain to those clips. If you recorded those clips with a high bit rate and if you aren’t raising their level too significantly you can get away with it without too much trouble. However, if you need to raise the level quite a bit, you may notice it getting noise as you are also amplifying the background noise as well as raising the noise floor.
On the opposite end, if you noticed that you recorded the level too high, this is often a problem that is much harder to fix, as when you clip the audio the information is no longer there. What you can do if the audio is only clipping in a few places is get the person whose audio is clipping to go into a studio, or if you are working on the lower end of the scale, somewhere quiet without too much reverberations, and record what is known as ADR. Automatic Dialogue Replacement is when you have the person read their lines while trying to match the tone, level, and speed. Make sure to use the same microphone in more or less the same position. If you also have some room tone that you can lay underneath, this helps to cover over the mistake a bit more.
The best way to fix mistakes in audio is to be prepared before they happen and never have them happen at all.
