Kenyon Gyro Basics
The first question is why even use
gyros when there are stabilized cameras and lenses? Some of these work very
well in many situations, but one or two gyros on your existing equipment might
be cheaper and more flexible than an expensive lens which might not be readably
available. As far as I know, there are no 35mm motion picture stabilized lenses
available and I don't know of any "hard" lenses that are gyro stabilized.
I have applied gyros to cameras from
3lbs up to 35lbs. The principles are the same in every application, but the
heavier cameras are harder to support and attach to a supporting system.
As you read, if there are issues you don't understand, read on and hopefully
they will be explained or become clearer. Study the examples. I have separated
the different components of inertial camera stabilization so they can be addressed
individually. Please read
Definitions and Principles of Inertial Camera Stabilization. All of these
principles apply except rigging the gyros as counterweights at a distance.
Definitions: CG = Center of Gravity,
Camera System = Camera, gyro, hardware connecting the two and anything attached
directly. The camera system does not include the isolation and support systems.
I have found Kenyon Gyros to work
best when:
1. The camera is securely attached
to the gyro or if both are connected together by hardware, the hardware is stiff
but as lightweight as possible.
2. The gyros are mounted as close as possible to the mass of the camera. The
gyroscopic stabilization effect of a Kenyon Gyro is greater than its value as
an inert counterweight at a distance from the camera.
3. Whether the camera system is supported by hand or connected to support hardware,
it is supported at the CG or symmetrically opposed on axis with the CG of the
camera system. (Note the "trapeze" application.)
4. The camera system is dynamically balanced about the CG before the gyros are
running. The system will not seem very stable before the gyros are up to speed
but should feel balanced about the hand grip/s.
5. The isolation, connection and guidance systems have the least mass. They
can have some flexibility, but the camera system cannot.
6. If using a combination of two different size gyros, the smaller is used for
roll stability.
7. The connection system (camera system to isolation system) should have the
least friction.
8. Cables exit the camera system right under or near the CG of the camera system.
9. There is no direct eye or body contact to the viewfinder.
10. The Kenyons are up to speed after dynamic balancing. (About 7 minutes.)
11. The system design is "ergonomic" and includes making the operator
is safe, comfortable and his controls convenient.
12. The weight of the camera and gyro is supported by something other than human
arms if over four pounds total when all of the above conditions are met.
13. The CG adjustments are easy to make and parts can't come off while adjusting.
CG balancing is much more sensitive at the CG than at the extremes.
14. If more than one spring, bunji or rubber tubing is used, they are attached
symmetrically to the camera system and are of the same type and length.
One Kenyon Gyro Stabilizer will drastically
reduce vibration and jolts in 2 axes. If the gyro is in line with the lens and
the base level with base of the camera, the gyro will stabilize pan and tilt
movements, but not horizontal roll. A second gyro at a right angle and vertical
to the first gyro, will reduce horizon and double tilt stability. If there is
horizon roll with both gyros running at speed, turn the second vertical gyro
180 degrees.
Dynamically balance the camera system
before powering the gyros. It is more difficult and a bit dangerous to attach
the gyros when they are at speed. If attaching at speed, do it slowly and with
caution while securely supporting the camera system. Some of these applications
shown here do not lend themselves to convenient "parking" of the rig.
Consider lightweight protrusions that would allow the rig to be set down or
a cradle to be rested (parked) in.
When dynamically balancing the camera
system before powering up, the power cables should not hang loose but should
be supported close to the gyro so they do not tug on the camera and adversely
affect your balancing. For operation, the cables should exit below the CG of
the camera system so they don't effect the balance of the camera system.
Don't lift a heavy camera system
by the camera. The tripod mounting plate of most cameras is designed to break
away before the body of the camera is damaged. It is NOT designed for lifting
extra weight. I suggest first putting a rig on a supporting mount and then adding
the camera if possible.
Handle the gyros carefully if running
or not. If hanging them from bunji, rubber tubing or springs consider a secondary
loose safety strap so the gyros and camera can't be dropped. I prefer small
locking carabiners instead of "S" hooks.
The KS-4 weighs 2.13lbs, KS-6: 3.25lb,
and KS-8: 5.13 lbs.
When designing a gyro assisted or
an inertial stabilization system there are sources of offending motions to consider.
1. Motion from the operator's inability
to hold a camera stationary. When holding a heavy camera muscles start to "tetanus"
(fight one another) with fatigue. Supporting the weight of the camera in a favorable
operating position can reduce this.
2. Motions of the operator's body
while walking or guiding camera. The arms are excellent isolators and support
for lightweight cameras. Heavier cameras need mechanical help.
3. Motions from a vehicle that are
transmitted to the operator's body. It helps a lot to make the operator comfortable,
support his arms, and make the controls ergonomic.
4. If the camera is supported from a vehicle, motions from the vehicle effect
the support of the camera system. Springs, bearings, bunji, rubber tubing, levers
and arms can isolate these motions.
5. Wind from nature or vehicle motion.
Read and follow all the cautions
in the Kenyon instruction book. Refer to Kenyon's website for more information,
www.ken-lab.com.
© Copyright 1999-2004 Ron Dexter.
All Rights Reserved.