CML - Cinematography Mailing List


Car Mount Vibration Issues

>Published : 26th June 2006

>(In Particular Related to Image Stabilizer in Sony PD150)

>I am having some vibration problems when mounting various Sony miniDV cams on a car-mount camera rig. The rig is rock-solid so that is not the problem.

>The problem occurs at/over certain speeds. I have tried turning the camera's image stabilisation mode on and off. Having it on produces the expected problems as if you had turned it on when mounting to a tripod. Turning it off, I still get the problem because as understand it the lens is still "floating" inside the camera and not stabilized using the magnets (that come into play in stabilized mode).

>Has anyone else had this problem? If so, do you know any solutions or work-arounds for it. (other than going to film or a lipstick type camera).

>John Early
Long Beach, California

>John Early wrote :

class="style11">>I am having some vibration problems when mounting various Sony >miniDV cams on a car-mount camera rig.

>I've had similar problems. It first they weren't noticeable, but as we used continued to hood mount the car they became more noticeable.

>Eventually we looked at the original footage, and we could see it happening. I don't think there is a solution except perhaps to try a soft mount, like the bean bag. we were using the suction cup mount on a Jeep. Ours was a PD 150, and I don't think it is robust enough to handle all the vibrations.

>Steven Gladstone
New York Based Cinematographer
Gladstone Films
CML East Coast List Administrator

>I ran into similar problems with a Panasonic EZ-1 (great little camera way ahead of it's time) mounted on various emergency vehicles using a 3 suction cup mount as well as the traditional hood bridge. The biggest lesson learned was that the plastic around the mounting screw was not strong enough to keep the body of the camera from flexing. It's critical to stabilize the camera from both the top and bottom securely. Carefully use a mafer or Cardolini to the top handle or my favourite, use a hot shoe to baby pin adapter commonly used to mount obie lights, then grab the pin in a c-stand arm triangulated back to your mount. This does wonders for stabilizing these flimsy little camera bodies.

>You mentioned that your mount was rock solid, if that included triangulating to a top mount then I apologise for telling you what you already know. But I've had no problems with this type of mount on the EZ-1, pd150, gl-1 or DVX100. In fact, we had one shot from the hood of a jeep that looked so smooth (gl-1 with stabilization on) that you couldn't tell the car was moving! The camera was looking up through the windshield at a cloudless sky and it looked like we were parked. We reframed and re-shot with the stabilization off and achieved the slight vibration we wanted for the story.

>Hope this helps,

>David C. Smith

>John Early asks:

class="style11">>"I am having some vibration problems when mounting various Sony >miniDV cams on a car-mount camera rig. The rig is rock-solid so that is >not the problem."

>Wind can be a problem as it can cause the lens shade to "cup" the wind, thereby vibrating it. Also 3 chip cameras can sometimes have an issue with just basic vibration.

>I've had pretty good success with PD150's, DVX100's and the like by removing everything from the camera I can...including the mic. It you really need audio, loop it!

>Depending on the type of shot you are doing, you can also deflate the tires a bit so the vehicle is slighting spongy, thereby absorbing some vibration.

>I did a race car rig once and the engine was so powerful that just racing the engine while standing still caused visible vibrations. I wound up using 1 chip lipstick cameras which really did the trick.

>That's what they use for NASCAR!

>Allen S. Facemire-DP/Director
SaltRun Productions,inc. Atlanta/Norcross, GA

>In response to John Early's car mount vibration issue...I too failed to mention just how important it is to get the camera really battened down. As it was brought up in an early response post... that little screw hole isn't big or strong enough to do much more than get the camera placed and to keep it from sliding around.

>I use ratcheted cargo straps that either go all the way around the car or just around the car door if it's door mounted; and then after it's all said and done I finish the rig off with fibre tape. I then pinch the tape together which draws the tape tighter.

>Works pretty good!!

>Allen S. Facemire-DP/Director
SaltRun Productions,inc. Atlanta/Norcross, GA

class="style11">>…I am having some vibration problems when mounting various Sony >miniDV cams on a car-mount camera rig….

>It's not just the flimsy-ness that is the problem; it's also the lack of mass.

>Adding weight to the mount helps. Ask the rigging grip to add twenty pounds of lead to the mount as close to the camera as possible. This will affect the nature of the vibration in a positive fashion.

>Adding a pick point at the top of the camera, as David S. points out, is smart rigging.

>Rigging cameras to cars is skill blending into art. And, like any other skill - you get what you pay for. Get an experienced rigger and the footage is more likely to look good. And for dozens of little reasons (tricks) you would never think of.

>David Perrault, CSC

>My experience with Prosumer Cameras on my Camera Bikes is very simple.

>I find that the nature of these cameras is that the construction of the lens system is that the zoom , focus and iris mechanisms are almost always spring loaded which means that vibration will cause problems. Non Spring loaded professional lenses escape many of these issues.

>If you cannot lock down a lens (not possible on most prosumer equipment or anything with non detachable lenses), then you will have issues.

>The best bet in using a car mount is to use the right equipment which means using manual lenses that physically can be locked down.

>A year ago I had a client who insisted in using a DVX 100A against my advise. Every 30 seconds the camera shut down and recycled because of the vibration.

>This year during the test of a FX1 a similar problem occurred with the focus . . .
"Simple is Better"

>Mark Forman
Mark Forman Productions, Corp.
Forman Camera Bikes

>David Perrault writes:

class="style11">>>Adding weight to the mount helps. Ask the rigging grip to add twenty >pounds of lead to the mount as close to the camera as possible.

>All else being equal this will lower the resonant frequency of the camera, which could INCREASE camera shake because car vibration is usually of a lower frequency than that of a camera. It will also put more stress on the mount.

>In a mounted situation, a lightweight camera is usually advantageous with respect to vibration... but what you want is to add RIGIDITY to the mount, not mass. The idea is to get the camera to effectively become one with the car, which is itself highly damped because of its mass and suspension.

class="style11">>Adding a pick point at the top of the camera, as David S. points out, is >smart rigging.

>That's a very effective way of adding rigidity; i.e., to prevent the camera from overshooting vibrationally like a whip antenna.

>Dan "loves a good mount" Drasin
Marin County, CA

>I've shot a number of car-mounted scenes with the DVX100A and never had any issue like you describe. I'd be interested in seeing the mount that was used, but we were running tapes for 40-60 minutes on highways, bumpy rural roads, etc. and never had any problem other than the occasional pothole. The director was in the back and knew to get safety takes whenever they hit a big bump.

>Are you sure it was rigged properly?

Jim Eagan
NY editor/cameraman

The wheelbase of a bike is much shorter than a car and the G forces are much higher than an automobile on most impacts. The mount I use is a 100mm Sachtler bowl on special rails with a standard 100 mm head which I have used for 13 years without any problems.

In 1996 the mount was severely tested on the Olympic Mountain Bicycling Race Course in Atlanta. I used an Arri S with primes following the athletes without any problems at all for a simulator film.

>Mark Forman
Mark Forman Productions, Corp.
Forman Camera Bikes











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