Tuesday, August 24, 2010

Tech Tip Tuesday: Radio in your Audio?

Today I'm excited to share a Tech Tip with you that I learned from one of our mentors, Claire Beach, last week during a Reel Grrls shoot.

Our summer Apprenticeship Program for advanced students pays Reel Grrls participants a stipend to create promotional videos for local non-profits (who do not have to pay for the video they receive–pretty awesome right?!). This year, one of the videos we are creating is about women's suffrage, and will celebrate the 100-year anniversary of women receiving the right to vote in Washington State. 

Last week the Suffrage Team was setting up for an important shoot with author Patsy Clark. They had two lavalier microphones hooked up to their main camera and the audio levels looked like they were coming in fine, but when the camerawoman put on her headphones she noticed a low level of audio coming through that sounded like a BBC radio report. Huh?? That's right. Our mics were picking up a radio station!

Believe it or not, this happens all the time. Why you ask? Well, according to the internet, it can happen for lots of reasons, but this is probably the one we were dealing with: "Sound systems are made up of several pieces of electronic equipment as well as a lot of wiring. Each run of wire is potentially an antenna."

So the wires of our microphones were acting as antennas, picking up a radio station and broadcasting it through our video camera. Yikes! So, how do we get rid of it? Well, Claire had a neat trick to "shield" the connectors on the mic cables:

That's right, regular old aluminum foil! In fact, this particular foil Claire kindly rescued from her lunch. We wrapped the foil around each area where the metal shields surrounded our XLR plugs. Then the camerawoman, RG participant Julia Levy, listened for the radio station again:

It worked! With the mic cables shielded, our valiant RG team went ahead and filmed an excellent interview with Patsy Clark. Foil saved the day!

Don't forget, there are lots of different reasons why your mic might pick up a radio station, so use the bounty of the internet to explore further if this tech tip doesn't solve the problem for you the next time you come across it. Still, it might be a good idea to add a little piece of foil to your filmmaker's emergency kit (I know you have one!) just in case.

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