Walkie-talkies and the XL2

[Eric Elliott]

Had a weird problem on a shoot this weekend that I thought I'd share.

The image from one of our cameras was "jumping" just after we started rolling. The AD on the monitors was yelling, "Who's bumping the camera?" It turned out that when the director keyed the transmit button on his walkie while leaning over the camera, it somehow affected the circuitry of the image stabilizer, causing the image to jump. When he took a step away from the camera the problem went away.

Just a heads-up.

[Andrew Wills]

Ya, same thing as mobile phones aint it? I think (don't quote me on this) its the electromagnetic current that runs through devices like that that pull or push the image in strange directions. You can also get it from large batteries near monitors or TV's.

[Laurence Kingston]

Yeah, somebody posted recently about this with the Sony cameras as well.

[Bill Porter]

Did you check the tape later? I'm curious whether it actually did affect the image stabilizer or whether it only affected what was outputted to the monitor.

[Eric Elliott]

Yep, it was on the tape, too.

[Bill Zens]

Out of curiousity, was his walkie talkie a Nextel brand? They send out an RF signal that will cause interference with your equipment, whether sending or receiving, or just talking on the phone. Your description sounds just like the Nextel RF interference pattern.

[Greg Boston]

Originally Posted by Bill Zens

Out of curiousity, was his walkie talkie a Nextel brand? They send out an RF signal that will cause interference with your equipment, whether sending or receiving, or just talking on the phone. Your description sounds just like the Nextel RF interference pattern.

Bill,

This problem isn't limited to Nextel. Most all cell phones periodically transmit a signal to let the cell system know their location. It started with the digital phones. If the received signal goes away, the phone will transmit as it searches for a new tower. That's why your cell phone battery will drain quickly if you are in an area of poor coverage.

=gb=

[A. J. deLange]

Nor is it limited to cell phones. Any device which radiates electromagnetic energy, intentionally or unintentionally, has the potential to interfere with other electronic devices. Conductive elements of the victim device act as antennas and there is often some circuit element which will rectify the rf picked up by the "antenna" thus introducing unwanted currents into the circuit. It is part of the equipment designer's art to render devices immune to this EMI but note the use of the word "art". This is why the airlines make you turn everything off in the initial and terminal phases of flight. AFAIK no computer, cell phone or CD player ever has interfered with aircraft nav gear but the fear is that it might.

[Greg Boston]

Originally Posted by A. J. deLange

Nor is it limited to cell phones. Any device which radiates electromagnetic energy, intentionally or unintentionally, has the potential to interfere with other electronic devices. Conductive elements of the victim device act as antennas and there is often some circuit element which will rectify the rf picked up by the "antenna" thus introducing unwanted currents into the circuit. It is part of the equipment designer's art to render devices immune to this EMI but note the use of the word "art". This is why the airlines make you turn everything off in the initial and terminal phases of flight. AFAIK no computer, cell phone or CD player ever has interfered with aircraft nav gear but the fear is that it might.

Very true. I can't have my XL-2 powered up in proximity to my HDTV when receiving OTA signals because it tears up the picture. Obviously, the XL-2 is the radiator in this equation. Oh the stories I could tell about strange things that happen when rf energy gets into devices that it's not supposed to be in. :-)

-gb-

[James Emory]

Yep. Laurence, you're probably referring to this thread.

www.dvinfo.net/conf/showthread.php?t=35565