Sync Variance Limit - Barco MCM-400 HFR User Manual

12.7 Sync Variance Limit

Description
The Sync Variance Limit allows to generate a certain delay between the incoming signal and the processing of it. It is expressed in
source lines.
The reason why this delay is needed is because the signal processing in the projector is faster than the source signal itself.
If the Sync Variance Limit value is set too low, the previous frame will be processed. This implies that the delay between incoming
signal and display of it will be large (16 ms). No image distortion will occur however.
incoming signal
signal processing
in PMP (1st step)
incoming signal
v
signal processing
in PMP (1st step)
incoming signal
signal processing
in PMP (1st step)
Image 12-12
If the Sync Variance Limit value is only just high enough (= critical value), it might be possible that sometimes the actual frame is
processed and sometimes the previous frame is processed. This will lead to a jumping image or frame tearing (= image distortion).
The best value for the Sync Variance Limit is about 50 microseconds higher than the critical range. This guarantees the display of
the actual frame without distortion and with minimum delay.
Adjusting the Sync Variance Limit
1. Make sure the required geometry file is active and select the scaled pattern Moving hatch.
To select the pattern, in the OSD, navigate to Installation > Scaled patterns > Moving hatch... and press ENTER to select.
2. Navigate to Display setup > Sync variance limit... and press ENTER to select.
Image 12-13
Image 12-14
R5909056 MCM-400 HFR 11/05/2016
frame B frame C
x
frame B frame B
x (= sync variance limit) is critical
frame B frame C
frame A frame B
v (= sync variance limit) is too small (<x)
frame B frame C
z
frame B frame C
z (= sync variance limit) is good (>x)
frame D
frame D
frame D
frame C
frame D
frame D
12. MCM-400 HFR tools
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