About alc and eei operations – JVC KY-F75 User Manual
Page 49
E45
About ALC and EEI operations
ALC stands for Automatic Level Control and EEI for Extended Electronic Iris. (
੬ page E28)
By making the respective settings, the Automatic Level Control (ALC) will operate under dark
lighting, and the electronic shutter (EEI) will operate under bright lighting. Furthermore, setting
the IRIS mode to AUTO will synchronize sensitivity, iris and electronic shutter so that an appro-
priate signal level can be acquired automatically at all times.
The ALC mode increases sensitivity from 0dB to +12dB under dark lighting and the EEI
modeautomatically adjusts the range of 1/7.5 s to 1/2384.7 s (calculated value) under bright
lighting. In other words, the signal level is adjusted in the range of 2 graduations of the aperture
under dark lighting and 8 graduations under bright lighting. When the IRIS mode is set to manual,
the sensitivity and electronic shutter change continuously while the iris setting stays fixed. (
੬
page E27 Iris mode)
This feature holds the advantage of being able to shoot under changing light conditions without
the depth of field altering.
MEMO
• When EEI is used, the amount of change in one step of the signal level will be large and the precision
becomes bad as the shutter speed is faster.
Operational range (when ALC MAX: +12dB)
Light: lx
4
8
16
31
63
125
250
500 1000 2000 4000 8000 16000 32000
640000
64000
EEI LIMIT
: When 1/7.5s
0dB
F2.8
F4
F5.6
F8
F11
F16
1/7.5
1/15
1/30
1/60
1/120
1/2384.7
ALC
EEI
+6dB
+12dB
EEI LIMIT
: When 1s
0dB
+6dB
+12dB
1/1.871s
1/3.75s
EEI
ALC
Auto Iris