Posted by Bill Farnsworth on 08/21/07 05:58
> "peter" wrote ...
>>I have a cheap video tripod head that would tilt forward if the
>>camera is already slightly tilted forward, and would tilt backwards
>>if the camera is already slightly tilted backwards. The only way to
>>cope with this is to increase the tilt friction. But this makes it
>>harder to tilt smoothly; it would jerk. I'd like to balance the
>>camera so that the tilt friction can be reduced to near zero.
>>
>> The more expensive tripod head have a sliding plate to move the
>> center of gravity of the camera directly over the pivot point. I
>> don't see how this solves the problem. As long as the center of
>> gravity is *above* the pivot point, the problem is still there. The
>> solution should be to make the center of gravity lie on the same
>> axis as the pivot point, and the only way to shift the center of
>> gravity there is put a counter weight below the pivot point. This
>> is like balancing a wheel; if one side is too heavy, you put a
>> weight on the opposite side.
>>
>> But I have not seen any such counterbalance on any videographer's
>> tripod. So I wonder what the established solution is.
>>
>> Another possible solution is to use more complex mechanism to
>> create a virtual pivot point inside the camera body where the CG
>> is?
Professional fluid heads worth their salt have adjustable and or
multiple counterbalance spring mechanisms already built in. That is
why you can't see them.
The sliding plate does nothing more than make it easy to center or
"zero" the equipment's mass precisely on top of the apex of the tilt
axis. Or wherever the pivot point is needed.
The friction or drag adjustment is meant to dampen not counterbalance.
A properly set up professional fluid head will remain stationary in
most tilt angles.
Bill Farnsworth
www.billfarnsworthvideo.com
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