With this blog, i hope to demystify some of the audio world and help all of you out there to get the best audio recordings possible while shooting with the wonderful array of new DSLR cameras.
DSLR cameras are fantastic things, not only can they shoot amazing stills but they have the added bonus of being able to shoot high definition video too. This puts the creation of high quality video and film in anyones hands, some great films have, and are being created with DSLR’s. For example the season finale of the show ‘House’ was filmed exclusively on the Canon 5D MkII cameras, they have also been spotted being used in big budget hollywood movies for their compact size and ability to capture angles a normal hollywood film camera couldn’t.
The only downside to using a DSLR is the audio (just like most cameras unfortunately). Being primarily a stills camera with the added bonus of shooting video the audio side of things was most likely last on the list of things to add. This means that there is no standard xlr connection, no way of monitoring the audio you are recording, Automatic Gain Control (AGC which can cause a lot of noise in recordings as it lowers and raises the gain control depending on the ambient noise around) and poor A/D conversion, getting good quality and usable audio into a DSLR can be a bit of a nightmare.
When recording audio while shooting with a DSLR you have two options 1) record your audio using a separate digital audio recorder with off camera microphones or record through a dedicated mixer to camera, with both of these options you gain the ability to monitor what you are recording (i will cover this in a later blog)
2) use one of the plethora of microphones available that attach to the hotshoe and connect via the 3.5mm jack socket. You can find these types of microphones made by most major audio players from Sennheiser, Rode, Sony and even Nikon make their own.
All of the on camera microphones attach via the hotshoe, most have a -10db pad (or equivalent) for recording loud sources, a low cut filter and input their signal via a 3.5mm connector to your cameras line/mic input. They come in two flavours mono or stereo, Mono being good for speech capture and stereo being better for capturing speech and more of the ambient noise of a room or space.
When using a mono on camera microphone the signal will be recorded to both L and R channels simultaneously, if using a stereo microphone one side will record to the left and the other to the right. The reason for recording a mono signal to both channels is not just one of convenience but one of necessity as a very good safety precaution. With the Canon 7D and its 2012 firmware update, Canon 60d and 5Dmk3 DSLR the introduction of manual control of the left and right audio channels and being able to switch AGC off, you can set one side to be recording a signal of around -12 db and above while the other is set to be hitting -20db and above. This means that if you suddenly find yourself in front of something or someone incredibly loud that causes a loud peak on one channel you have a safety version on the second. This can save your bacon when it comes to editing if you are just using the on camera recorded audio and working alone. Make sure you set and check and double check your levels while filming as you can’t hear if the signal is peaking so make sure you keep an eye on your levels so you get no nasty surprises in the edit.
Now earlier i stated how you couldn’t monitor your audio inputs… well this is about to change. Rode shall be releasing the Rode Video Mic HD later this year. It comes not only with a headphone monitor output but a built in flash recording device. Thus giving you 2 choices of where to record your audio or using it as a back up option if required. With the new microphone based on Rodes ntg-3 boom microphone it should sound rather good too.
There is also a second, but lesser known option for recording and monitoring quality sound on your DSLR that is available to buy now. This comes in the form of the Lindos VM1 telescopic video microphones, its MP1 microphone pre-amp and the correct adapter for your camera. Lindos also provide an add on headphone monitoring adapter as well. This whole kit comes in at just over £200 which in my opinion is a bargain for what you get. Lindos being an audio test equipment manufacturer have really concentrated on making a microphone that has a truly flat response across the frequency spectrum in an incredibly tiny package, along with producing adapters for the most popular DSLR cameras that not only attenuate (minimise the noise from the cameras internal mic pre amp), but equalise the bass response for each cameras mic input (as they all seem to roll off dramatically on the lower end) giving you the best all round audio capture.
So there you have it, the current options for getting good quality audio into your DSLR as simply and (mostly) cheaply as possible. There are more expensive and higher quality options which i shall cover at a later date but for now i think that covers it, so go out and make some great films with some great audio.
Trinity Audio Media Solutions 