Nothing to gain from AGC

After many tests I accepted the fact I have to capture audio on a seperate device.

I’ve had to make affiliations for the better part of my life. I went with Sega when my cousins had Nintendo as their console of choice. I stuck with the now software-only video game company as they released the Master System, Genesis, Sega CD and 32x. Yes I had all of those systems. No, I don’t regret it. Really. I had yet another choice when the Saturn was to launch against a heavily hyped upstart in Sony’s PlayStation brand. I went out and dropped $599 on Sega’s 32-bit Saturn, wrote an article for the school paper and convinced a handful of people to hop on the Sega Bandwagon. We were a lonely bunch. Yes, I regret that. I was a Warrior fan when they traded Chris Weber for Tom Gugliotta and stuck with them through the Sprewell choke and Mookie playing hooky. Let me use that HD DVD as a frisbee because I’m popping in a BluRay. Give me WCW not the “Hitman” headlined WWF. I will supply you with charts and graphs if you tell me a PC is better than an Apple. And if I could take a picture of your face right now, it won’t be with a Canon or Nikon.

I’ve made my affiliation, for better or worse, with the Sony line of cameras. I’m loyal to them. Which is too bad, because they frustrate the hell outta me. That proprietary hot shoe is a nuisance causing me to seek obscure adapters through eBay in order to mount a simple microphone. Speaking of which, an external microphone on a Sony Alpha Camera or Nex Camcorder is a moot point because of AGC. Auto Gain Control (AGC) is the only option you have when recording audio on a Sony Camera. It means that it determines for you how sensitive the mic is. So in a noisy environment, it’ll crank the levels down so you don’t pop any speakers on playback. In a quiet environment it will push the levels up as it searches for some kind of audio to record. That’s when the real problems occur as it’ll pick up and amplify the lens motor noise and just render the audio useless. AGC will also introduce a faint humming in the background that screams amateur which is not what you want if you plop $2,000 on the a77 or Nex-VG20. It doesn’t matter if you mount an external microphone, all those unwanted noises will be picked up and recorded on the audio track.

You would think Sony’s algorithm when designing this SLT specific external microphone would cancel out lens noise. It helps but not enough to make usable audio. I personally could not tell the difference from the onboard mic when sound was placed directly in front of the camera.

Unfortunately, Canon saw this as a problem and have fixed their line of cameras through firmware updates. 3rd parties introduced Magic Lantern that gave Canon DSLR users full audio control. Nearly two years ago! The a57, a37 and a77 came out months ago and Sony chose not to address these issues. You can bypass picking up lens noise by focusing manually of course but then you can’t utilize the major selling point of the Sony’s SLT line with their blazingly fast phase detection auto focusing. I’ve tried the Rode Video Mic Pro and Sony’s own ECM-ALST1. They both suck on my a57 because they not only pick up but amplify lens motor noise.

Now most pros will record audio separately anyways. This gives them a second audio track, which is handy to have so one can serve as a back up, and the ability to control/monitor audio feeds. Something like the Zoom H2, which I use, can record audio and be synced to match the video later in post. It adds a wrench to workflow but the results are usually better than recording off a shotgun plugged into a camera, manual gain or not. But in ENG or run-n-gun type situations this won’t be an option and it’s no wonder paid work is usually done on a Canon or Nikon if shot with a DSLR. On the bright side, Sony’s xx7 line of cameras have a pretty good onboard stereo mic that makes syncing in post easier.

Rode is a standard for prosumer audio mics. This shotgun has -10db, 0 and +20db settings and they all stink on the Sony because AGC will crank up until it finds something. Usually, you guessed it – lens noise. Maybe silent films is the way to go. “The Artist” did well this year, yes?

If Sony’s history says anything then Alpha/Nex users cannot look forward to a firmware update to resolve this issue. Sony does pay attention but they usually address them in the form of a new product. It’s a shame. Audio is important, it’s 50% of the experience. You can usually take a shitty video track and with good audio, make it usable. It doesn’t work the other way around. Delving into video production has given me this unnecessary headache but I’ve made my affiliation. Hey, Sega turned out alright, right?

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