"There one thing that you absolutely cannot get wrong in filmmaking, and that is sound"
-Paul Sloop, Cleveland International Film Festival
Audio--it's the easiest thing to screw up, and the last thing you want to get wrong on a film. Bad audio can sink your film faster than Marvel can pump out superhero films.
Great audio is an investment. An experienced technician can make a thousand dollar film feel like it had a ten million dollar audio budget just by the way they record and mix your sound. But even if you don't have the budget to spring for a good sound tech, that doesn't mean you need to suffer with bad audio.
Here are a few measures you can take to help make sure the sound in your film stays on track.
1. Control your environment
The first step to getting good audio is preventing a situation where you'll have BAD audio. You'd be surprised how many inexperienced filmmakers choose to shoot scenes in busy intersections during rush hour traffic, outside during a windstorm, or with a marching band rehearsal one block away.
You may not have a budget for great equipment, but you CAN think ahead to avoid these kinds of situations that will have distracting incidental audio in the background.
2. Stop using your camera's microphone
DSLR cameras have revolutionized independent filmmaking, and give the average filmmaker an opportunity to make films that LOOK cinematic. However, the built-in microphone on these cameras isn't designed to provide that same level of professional audio quality, so stop trying to pretend that it does.
Audio is one situation where you generally get what you pay for, so it almost always pays to invest in good equipment. However, ANY off-camera microphone is better than trying to use what comes built in to your DSLR.
3. Get up close and personal
Most audio gets ruined because it's recorded from too far away. When you try to boost the levels in post, the result is also boosting the background noise, static and any other incidental sound besides what you intended on recording.
Always try to get the mic as close as possible to whatever it is that you're trying to record. The joke about the boom guy that's always dropping the mic into the frame when he gets tired? The reason they're doing that to begin with is so they can get in tight with mic placement. So have your boom operator muscle up and hold that mic as steady and as close as possible, while still being out of the shot.
4. Have dual system sound
While your on-camera microphone might not be well suited for film-quality audio, it does have a more practical use--to help you sync up your sound. So even though you don't want to use the audio from your on-camera mic in the final version of your film, you should still use it to record a reference track of in-sync audio on the set.
You'll have a backup just in case your primary audio recording device somehow fails, and it's also much easier to sync up the audio from your primary source with your on camera audio track in post than if you had no reference track to match it up with.
5. Use a clapper
Speaking of syncing--remember those old school movie clappers that get smacked when the director yells "Action"? They don't just make a fun movie set prop, those actually serve a function. Clappers help sync up the sound from your reference audio track with the sound track from your your primary audio recording device so all the audio stays in sync with the video.
That clap produces a distinct audio spike that makes it easy for your editor to align the audio tracks in post. If you don't have an actual movie clapper, clapping your hands can have the same effect. Do this at the beginning of each take to make it easier to line up the audio tracks when it comes time to edit.
6. ALWAYS record room tone
One trademark of bad audio is suddenly having NO audio. Room tone is the natural "white noise" that is present in any environment that you're in. You should ALWAYS record 60-90 seconds of just room tone in each location so that you can use it to mix and patch bad audio in post.
It's common practice to use digital filters during the editing process to drown out unwanted background noises that undercut your dialogue. But those same filters also take out the natural room tone as well. You want to have a separate track of room tone to mix in so there are no unnatural sound "vacuums" in your film.
Find these audio tips helpful? Get our free guide with 10 different ways you can instantly improve your film for free (or cheap) at http://www.gorillafilmschool.com/10-ways-instantly-improve-film-free-cheap/.
Gorilla Film School is an online hub which offers the resources you need to make your film or act on-camera by providing video training, workshops, templates, & tutorials, and more! You can find more articles like this one on their website: http://www.gorillafilmschool.com