Manual

Page 17
Using Sync-One2 effectively
There are some basic tips which when combined with an understanding of the statistics gathered will
enable effective measuring of synchronisation errors.
The light trigger is based on detecting the change from dark to light and is very sensitive. When testing
involves projectors however, it may be required to put Sync-One2 into the projector beam (facing the
projector, naturally) rather than rely on the reflected light from a screen. Audio detection is essentially
looking for the start of a noise, it doesn’t matter is the audio is in or out of phase. Ideally perform tests
in a darkened room with low ambient noise, doing so makes the distinction of the light flash and sound
easier to detect and so measurements will be more accurate and reliable.
When turning the unit on or going back into Measurement mode Sync-One2 will calibrate to take
account for ambient light and noise. It is best to hold the unit in the measuring position when turning
on or going back into Measurement mode such that the calibration can be optimally set for the current
measurement conditions and unit position.
In any given installation there will be a variance between all the readings taken. This is because when
digital processing is involved there will be slight differences in how the signals are processed, this is
where the use of statistics is the most useful to determine any given error.
Always take a number of readings to determine an error, to help smooth out the variances. Then the
average and span of a set of readings give the best indication of the situation in any given system. A
low span of readings means the system is stable in its operation, ideally a span of 10ms or 0.5 frames
or lower is ideal. The average will give the delay in the system, naturally an average of 0ms / 0.00
frames would be perfect but in the real world anything under 10ms or 0.5 frames would be hard for
anyone to detect.
For example, if after a series of measurements, the Show Stats menu gives the following screen…
…the low span of 2 milliseconds indicates the system is stable but suffers from a video delay of about
46ms. If this were a home cinema, adding an audio delay of 46ms and re-testing should result in a
synchronised solution.
If the same readings were obtained with a frame rate set, for example in a post-production
environment, the screen would alternate between the stats in milliseconds and frames. With the same
measurements with a frame rate of 48 frames/second set there is a span of 00.1 frames, which is good.
The average error is the audio leads the video by 2.19 frames, so adjustments need to be made.
A +046 M01
S 0002 ms +047
A+2.19 M01
S 00.1 25
F
+2.23