Non-Underwater, Technical, Video Question

[Rick Inman]

This is a non-diving video question, but someone knows everything on this board, so here goes.

We shot some footage last Saturday on top of a 250' rock for a rock climbing themed commercial. The rock sits about 1/4 mile from a mountain top that has about 6 TV RF towers that feed the airways for the local stations, and the towers are in direct line of sight of the rock top where we were shooting.

Looking at the dailies, all of the shots that were hand-held are fine, but all of the shots from the tripod, or from the jib have distortion and color bleed. My guess is that the tripod/jib acts as an antenna (rubber feet, not grounded).

The hand held shots are good enough, but on very close inspection I can detect some very minor effects as well. My plan is to re-shoot everything hand held (maybe even have the cameraman take off his shoes).

Any other ideas on how to shield the camera from the RF effects?

Oh, cameras are XL1s.

Thanks!

Rick

 

[f3nikon]

The video camera has a magnetic head to record on tape this is where the problem maybe coming from. You may have some luck with a video camera feeding into a digital DVD recorder since the DVD recorder uses a laser to record or use a film camera.

May also try covering the camera with aluminmun foil with a wire connected to ground. With all that energy effecting your camera just think what is doing to your body? I hope you arent glowing in the dark by now so limit your exposure.

Good Luck

 

[MarkH]

To isolate objects from magnetic fields or rf radiation, geeks use a Faraday cage, which is basically just a metal box around the object. I don't know the size of your camera, but an empty computer case would probably work. As mentioned, a layer of aluminum foil is easy, cheap and would probably work just as well. I've heard that a wire mesh, like chicken wire can work as well. Hopefully someone who knows more can chime in and tell me if I'm full of it.

 

[pakman]

I think you need to get your whole camera team some tinfoil hats...

 

[bluesbro1982]

To isolate objects from magnetic fields or rf radiation, geeks use a Faraday cage, which is basically just a metal box around the object. I don't know the size of your camera, but an empty computer case would probably work. As mentioned, a layer of aluminum foil is easy, cheap and would probably work just as well. I've heard that a wire mesh, like chicken wire can work as well. Hopefully someone who knows more can chime in and tell me if I'm full of it.

Thats about right. Aluminum foil does a decent job, and I dunno if an XL-1 will comfortably fit into an old computer cage... Shooting handheld sounds like a fun experience that I'd rather pass on...

A Wire Mesh will only work if the mesh itself is grounded, which might be dificult to do unless you have a piton in the ground that a past climber has hammered in.

Junkyard Wars-ish Thoughts: find metal panels maybe 2 ft by 2 ft (Sides of a compuer cage held by an assistant?) and place them in line of sight between the tower antennae and the cam head so that the cam is in the "shadow" of the panels... might be able to use lighting stands or what-not to do that... Maybe use a C-Clamp usually used for lighting to atach the reflector in a fixed position atached to the jib.

even better, lighting stands with foil / metal diffusion reflectors... possibly wrap a 10K diffuser umbrella / sun reflector with some more foil and use that as the "reflector" between the camera and the radio towers. If you have a light crew on hand they probably have that kind of equipment handy that can easily be covered in foil and stuck between the side of the camera and offending RF towers.

As far as the tripod / jib goes, a ground would be good. but dangerous if the weather changes. If you have a conductive piton / spike driven into the top of the rock somewhere by the climbers, get a long piece of decently thick wire and go from the botom of the metal tripod to the ground (Jumper cables work OK, but thats a poor mans solution that assumes you are close to the ground point) DO NOT do this if there is any hint of a storm brewing... you'll instantly become the path of least resistance, and its probably something liability wont' cover when they find out that you grounded yourself with big copper cables to the rock

I'm sure I'll have some other equally stupid ideas in the future, but my best thinking leads me to say to use light stands or something to hold a fixed RF-reflector between the cam heads and the microwave towers, along with a ground.

 

[Rick Inman]

This is all good stuff, guys (especially the hats ). And yes, there are several bolts permanently anchored into the rock that would make a perfect ground. And yes, I've got mylar reflectors I could place between the camera and towers.

Looks like another pre-shooting scouting trip to test ideas is in store. I'll let you know how it works out.

Thanks!

 

[Jeff_S]

My experience is that the best solution in this kind of environment is motion picture film. It's completely analog and won't be effected by any of the RF you're dealing with. On set, we're even careful about walkie talkies near video cameras.

Grab an Arri SR, a couple rolls of 16mm film, dust off your light meter, and head back up the hill.

Jeff Seckendorf
www.OneOnOneFilmTraining.com

 

[Empty V]

The problem with shooting 16mm is having to pay for the film, processing, and telecine. I do it all the time and it's very time consuming and expensive. You live in Spokane and I'm not sure how many post houses out there that can handle something like that. I suggest some gator clips and carboard wrapped in foil. I've never had to deal with this so can't say for sure. See if adjusting the gain helps with this. The XL1 does great in lower light situations, I used to have 3 of them. You can always "fix it in post." If you're on FCP it has some great color correction tools.

Billy

 

[Rick Inman]

My experience is that the best solution in this kind of environment is motion picture film. It's completely analog and won't be effected by any of the RF you're dealing with. On set, we're even careful about walkie talkies near video cameras.

Grab an Arri SR, a couple rolls of 16mm film, dust off your light meter, and head back up the hill.

Jeff Seckendorf
www.OneOnOneFilmTraining.com

What Empty V said.

Nothing I'd love more than to work with film. But this is the last of 5 theme spots I'm shooting that all need to have the same "look" (shooting all in slow 30, 16:9), and considering that I have ZERO experience with film, it could very well suck (hummm....just clicked your link. Maybe I need one of your classes on film??). Also, the the budget is already over.

The good news is, next year we are planning a major equipment upgrade.

 

[Empty V]

Nothing I'd love more than to work with film. But this is the last of 5 theme spots I'm shooting that all need to have the same "look" (shooting all in slow 30, 16:9), and considering that I have ZERO experience with film, it could very well suck (hummm....just clicked your link. Maybe I need one of your classes on film??). Also, the the budget is already over.

The good news is, next year we are planning a major equipment upgrade.

Smart choice my friend. you definitely want your images to match. Shooting on film is a completely different world. Once you start working with film you'll have to factor in speed of lens, iso of film, filter factors, tungsten or daylight film and the list goes on and on and on.

Shooting with the slow 30 filter is a great way to gain some extra light without adding a ton of noise.

So when are you shooting and what did you decide to do?

Billy