18
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Balancing the camera
12 Balancing the Vision 30 head achieves two objectives. Firstly, when a head is correctly balanced the
operator will need a minimum amount of even effort to move the head. Secondly, once balanced, the head
and its payload can be set to any tilt position and the head will maintain this position with “hands off”.
13 The graph (Fig 2.1) illustrates the relationship between load and centre-of-gravity (C of G) height and
may be used to ascertain the suitability of the head for any given combination of camera, lens and
accessories. The shaded area of the graph corresponds to those loads/C of G heights that can be balanced
over the full tilt range. The areas to the right indicate the progressively reducing tilt range over which the head
can balance higher loads.
14 Ensure the pan bar or bars with zoom and focus controls are fitted to the platform, that the platform is
horizontal and proceed as follows:
14.1 Turn the balance adjustment knob approximately 15 to 20 revolutions in the positive (+)
(clockwise) direction.
14.2 Position the centre of gravity of the camera/lens combination over the head tilt axis by adjusting
the platform slide. Slacken two slide lock screws protruding from the right hand side plate and by
operation of either slide adjuster knob, positioned one at each end of the platform slide, position the
slide and camera/lens combination to give equal 'fall-away' or 'centring' tendency in both directions.
Relock slide in position using the two slide lock screws.
14.3 Hold the pan bar to restrain possible movement about the tilt axis and release the CENTRE
LOCK (pull out and turn) and the TILT BRAKE (lever fully counter-clockwise).
14.4 By feel on the pan bar determine whether the platform 'centres' or tends to 'fall away' forwards or
backwards.
14.4.1 If the platform 'centres' decrease balance by turning the adjustment knob counter-
clockwise until an approximate balance is achieved.
14.4.2 If the platform tends to 'fall-away' in either direction increase balance by turning the
adjustment knob clockwise until an approximate balance is achieved.
14.5 Finely trim the balance and fore and aft adjustments to achieve accurate balance throughout the
full tilt range.
14.6 Re-engage CENTRE LOCK and apply TILT BRAKE.
Setting the tilt drag
15 Hold the pan bar and release the CENTRE LOCK and TILT BRAKE. Turn the TILT DRAG control knob,
on the left hand side, to the required amount of drag; clockwise to increase, counter-clockwise to decrease.
Setting the pan drag
16 The pan drag is set in a similar manner to the tilt drag by operation of the PAN DRAG control knob on
the right hand side of the head.
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