The popularity of shooting with HD-capable D-SLR (digital single-lens-reflex) cameras has resulted in a whole new range of audio challenges. In a nutshell, the audio on the new D-SLRs leaves something to be desired. Those in search of killer sound to go with their amazing HD images acquired with these new cameras have some major challenges ahead.
PRO-Quality Sound With D-SLRS
Q I recently began shooting a project with my new Canon EOS 5D Mark II about the club scene in New York. I often shoot interviews in noisy clubs and concert halls. I know enough that I need to have the microphone in close to the interviewees, but it still sounds bad no matter where I place the microphone. How can I record professional-quality sound with my camera?
A It sounds as if you’re shooting in some challenging environments for sound. I recently bought a Canon EOS 5D Mark II for an upcoming project, and I, too, have experienced the same sound quality that you’re describing. In comparison to professional sound recording gear, both professional and consumer video cameras have always featured sub-par sound quality. It has become common knowledge that still cameras like the Canon EOS 5D Mark II, Nikon D90 and Panasonic Lumix DMC-GH1 can shoot amazing-quality HD video, but feature less than desirable audio for many users’ requirements. The built-in microphones that these cameras feature are designed to simply record the ambient sound, but when professional-level sound quality is required, no built-in mic will suffice.
The Interface. When shooting with the Canon EOS 5D Mark II, you still need a way to convert the balanced XLR connections used on pro microphones to an unbalanced 3.5mm audio connection that the 5D Mark II can accept or an unbalanced 2.5mm connector that the Panasonic GH1 features if you’re shooting with that camera. Two candidates for efficiently converting the balanced audio into a signal that a D-SLR’s unbalanced audio connector can deal with are the new BeachTek DXA-5D and the juicedLink CX231. Each of these adapters has its own unique features, but the most important one is that both adapters allow you to monitor the sound being sent to the camera via headphones. Most of the new video-capable D-SLRs don’t have a headphone jack, so it’s impossible to hear what the camera is recording. Without monitoring what the camera is recording, the process of recording high-quality audio becomes difficult, if not impossible.
One unique feature on the BeachTek DXA-5D is an AGC Disable feature to reduce preamplifier noise during quiet moments. It allows you to override the AGC (automatic gain control) in the audio circuit of the Canon EOS 5D Mark II by feeding it a high-frequency tone that isn’t audible in most circumstances, fooling the 5D Mark II AGC into keeping the audio input at a constant level. The BeachTek also features built-in audio level meters.
The juicedLink CX231 allows you to interface with professional condenser/dynamic microphones and line level signals so it can accept your microphones, as well as line level output from a mixer, which I would think could be handy for your shoots at concert venues. The CX231 also has three gain settings, a three-position L/C/R pan switch and 48v and 12v phantom power, allowing battery savings when using microphones that don’t require the full 48v for phantom power.
Next Step: Double-System Sound Recording. For the ultimate in sound quality, don’t use the audio from your D-SLR. Double-system sound recording involves using a separate recording device to capture your soundtrack. In the recent past, double-system sound conjured up images of heavy, large and expensive Nagra analog tape recorders, DAT recorders and film cameras.