Image Engineering
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Measure the calibration values with a suitable measurement device (e.g., luminance
meter) on the preferred region of the chart
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With the measured value from the external measurement device, rotate the rotary knob
(A) to assign the calibration
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Switch between
“fine” and “coarse” to set the sensitivity of the rotary knob (A) by
pressing the button (B)
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Press the
“OK” button (C) to save the calibration and exit the calibration menu
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Press the
“Cancel” button (D) to exit the calibration without saving
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The last performed calibration will be activated
The LG3 is factory calibrated. Perform an individual calibration to use it with your charts.
3.4 Continuous illumination
Use continuous illumination when illuminating test charts. The continuous illumination is preset as a
default on the LG3 start-up. Read chapter 3.5 on how to enter and exit the flicker mode.
3.4.1 Power modes
Three power modes are available
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LOW
: 32 kHz PWM, variable duty cycle, stabilized illumination level
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NORM
: 32 kHz PWM, variable duty cycle, stabilized illumination level with higher
intensities
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HIGH
: direct current, not stabilized, high illumination level (over 150,000 lux)
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The illumination in the high-power mode is not variable by the user and is
preset at the maximum possible intensity
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Due to the high thermal stress, the high-power mode is available for 60
seconds at a time
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The device will not start the high-power mode if the LED temperature is too high
3.4.2 PWM (Pulse Width Modulation)
The LG3 uses pulse width modulation (PWM) to control illumination levels. The high frequency of 32
kHz allows a flicker-free image acquisition for most cameras. The constant voltage has the benefit of a
constant correlated color temperature.
