ARRI IVS 435, Instruction Manual

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Standard Video Controls
• Adjustment ring
5.2 Mechanical Iris
Only a relatively small portion of the light which goes
through the film cameras´s lens reaches the CCD-Chip of
the video assist as the light is shared between the view
finder, the CCD-Chip and the film. Therefore the IVS
lenses are designed for a normal usage with a totally
open iris to have maximum light on the CCD-Chip.
Variations in lighting are compensated by the IVS´s gain
control (automatically or manually).
Under certain conditions, such as when lighting is set for
low-sensitivity film (under 100 ASA) or for motion effects,
it is possible that the IVS´s gain range is exceeded. In this
case the mechanical iris of the IVS lens can be closed.
Check all settings on the connected monitor.
If the mechanical iris is closed more than
necessary, the IVS will compensate by increasing
the gain and improve the image brightness
electronically. This creates additional electronic
noise. Avoid that by opening the mechanical iris.