Guide to Audio
This three part series is about how to unlock professional audio on your DSLR camera. In Part 1 we established the importance of good sound – you can get away with a bad picture and good sound, but not the opposite. And as a one-product dedicated sound solution, a Rode VideoMic (Mono shotgun range for speech, Stereo VideoMic Pro for everything else) plus a furry wind cover improves audio enormously and protects against wind noise.
Now this is all very well, but once you have your shiny new microphone, how do you set it up? What camera settings should you use? What mic settings are best for recording audio with your camera?
First things first: attach the mic by pushing it onto the cold shoe of your camera, screw it in to hold it securely, and connect the 3.5mm plug on the mic to the 3.5mm ‘Mic’ socket on your camera.
Some compact system cameras might only have a 2.5mm socket – if that’s the case, just grab a third-party 2.5mm to 3.5mm plug adapter. If you have XLR connectors on your camera (lucky you!) then you may be able to use a specific plug to adapt your mic to use this connection.
If your mic needs a battery, then fit it following the instructions and turn it on. If you’re out on a shoot we don’t recommend turning it off in-between shots, as this only risks forgetting to turn it on. Your battery should last for days – so just leave it on all day during a day shoot. Packing a spare is always a sensible idea!
Now, the most important step you need to take is to go into your camera’s ‘Movie Recording’ settings and ensure that this is not set to “Auto”. Using Auto mode is like having an invisible hand constantly adjusting the volume for you, trying to make everything as loud as it possibly can be. And when you’re in a quiet room, that means it’ll be amplifying background noise and hiss – not particularly desirable.
You want silence to stay silent – so you have to set this setting to manual, and adjust the recording levels ourselves.
To test this ask your speaking subject to speak, or musician to play, and adjust the camera’s input level manually to an ‘appropriate’ level. Watch the level meters (normally a green/yellow/red bar graph) while your subject is making sound, and get the meters to hit around -12dB (this is actually marked as “12” on many Canon cameras).
If you have no marking on your camera’s bar graph, as a rule of thumb, you want their audio to be nicely hitting yellow but NEVER hitting red. The idea is to not record too quiet, but reserve a little ‘headroom’ above it in case your subject gets excited! So ask them to speak or play, and tweak input levels accordingly.
Some mics may have additional switches to review: the Rode Videomics have attenuators (marked -10 or -20: and in the VideoMic these are inside the battery compartment). These make the mic less sensitive, allowing you to record really loud sounds without the audio breaking up or distorting – which is great if you’re filming a gig. For many filming situations we won’t need to use these at all – we advise never switching them on unless you can’t get your bar graph/audio meters out of the red zone without them.
If you’re using a VideoMic Pro or a Stereo VideoMic Pro, you may have spotted a +20dB setting. This makes the mic more sensitive, and outputs a nice and clean loud signal. You might find that when shooting video with a DSLR or a mirrorless, turning up the input volume will mean that the camera itself adds hiss to your video sound. That +20dB switch defeats the problem. You can turn DOWN your input levels (on Canon cameras, try all the way to zero and then up one click) and with +20dB on you’ll still see a nice audio level coming in. But that audio will be clear of hiss: here the mic is doing all the hard work, so your camera can focus on being a camera.
The final switch you may see on your mic looks like a ramp – “/” – this is a high-pass filter. What this does is remove very low bass rumble (extreme handling noise, passing cars, low ambient murmurs in a big trade show or crowd) from your footage.
This is a frequency range that’s totally apart from speech, and is considered ‘audio mud’ that you would generally do well to remove, unless you have a specific creative reason for leaving it in, such as a band recording to include low bass guitar, perhaps. Unless your job is to specifically capture bass, we’d recommend leaving it on.
So now we have our mic attached and correctly configured. But how can we push the quality of our audio even further? What if we’re still getting some hiss? What range would a mic struggle to capture audio effectively – and if we find ourselves working in this range, what’s the alternative?
Stay tuned for Part 3.