Fibre Connection - ARRI ALEXA Series User Manual

Fibre Connection

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16.4 Fibre Connection
Figure 135: SMPTE 311optical fibre connectors
The ALEXA M utilizes SMPTE 311 fibre connectors and cables. The
camera head can be powered with hybrid fibre/power cables with a
length of up to 30m, if the body power supply can deliver 120 W in
total.
Note: When powering the camera head from the body, the power supply must
have an output of at least 24V due to a voltage drop over the hybrid cable.
If this is not the case, the head should be powered separately through
its BAT connector with a power supply that delivers at least 40W of
power.
For regular fibre cable, a signal loss of up to 10 dB is acceptable. 1 km
of fibre cable has a signal loss of 0.5 dB, while a fibre connector pair
introduces a signal loss of 0.5-2 dB, depending on the amount of dirt on
the optical contacts. Typically, a cable length of up to 1 km with 4
connection joints is still acceptable.
To connect the cable to the camera, make sure the cable direction is
correct. Line up the red guides and push the cable connector onto the
camera connector piece. A clicking sound indicates the connector has
locked. Plug the rubber caps of the connectors into each other to
protect their inside from dirt.
To disconnect the cable from the camera head, pull on the rubber end
of the connector in the direction of the cable. To disconnect the cable
from the body, push the metal ring of the camera connector piece and
pull on the cable connector in the opposite direction.