Beta Cam/Arri BL Rig
This is a prototype. I have built
working models for the Arri BL that worked quite well. This one took me 2 hours
to build out of scrap and loose parts. I will discuss here some prototyping
and the principles involved at the same time.
Attaching anything to a Betacam type
camera is not easy if you don't use the factory base plate which would raise
the camera too high above the shoulder. An Arri BL or similar camera is easier
to attach to because it has a strong mounting thread ahead of the shoulder.
This crescent shaped plywood piece
(1) allows the Betacam type camera to rest directly on the shoulder (2). The
shoulder is the support system (SS) and connection system (CS) for the camera
system (camera and counterweights). The SS and CS where the camera rests on
the shoulder, is also ideally at the CG of the whole camera system including
counter weights (3). There is little isolation other than the flesh above the
shoulder bone. A mock shoulder like a rounded block of wood on a light stand
will help for tuning the balance of the counterweights. Provide a slack safety
strap from an above support to avoid accidentally dropping the camera. I used
plywood for this prototype because it is easy to cut and parts can easily be
attached or moved with drywall screws.
I left the tubes (4) intentionally
longer to avoid cutting them too short too soon. The tube should be as light
and stiff as possible to make the counter weights more effective. I used welded
Speedrail © TEE fittings (5) in front / top, but Speed Rail © crosses
would work well as they are very strong without modification and symmetry about
the pipe center is not important here as it is in horizontal rigs. A finished
model could be 1/4" aluminum plate with the pipe stubs bolted through the plate.
This plywood prototype makes a good template for an "more professional" aluminum
As I cut the plywood I found out
what clearances were needed for the camera's right zoom handgrip (6) and around
the right shoulder. The plywood or aluminum crescent piece should not touch
the shoulder. Every Betacam camera presents its challenges to mounting without
the supplied base plate.
These bar bell weights (3) are only
1-1/2 pounds each, but do a lot at that distance to stabilize the camera. The
center holes of the iron gym weights were turned out on a lathe to the size
of the tube.
Guiding the camera at a distance
from the camera with the left hand (7) provides a lot of leverage to control
the camera. This is similar to the extended support camera rig.
With practice this arrangement works
quite well and provides much more stabilization than a camera alone on the shoulder.
Watch your clearances around people and going through doors.
With your right hand on a normal
forward Betacam zoom handgrip it is best to hold the lower horizontal bar toward
the rear with the left hand (7) to balance the control of the whole unit more
symmetrically about the CG.
For an Arri BL you will have to be
concerned about light leak to the film back through the eyepiece if the eye
is any distance from the eyepiece.
© Copyright 1999-2004 Ron Dexter. All Rights Reserved.