Re: [photo-3d] Re: 3D Camera Synchronisation

["Allan Griffin" <agriffin@xxxxxxxxxx>]

Yesterday, Robert Brand wrote:

>                                   I am however about to link up more than
the so called
> "wake up" sync on my Ricoh SLRs. The mod I have done already couples the
> power, wake up and shutter firing and I will now couple the other
functions
> such as mode and speed. As for Sync, both cameras will be triggered
through
> their individual processors - this differs from the "slave master"
> modification where one processor trips both shutters. The timing will be
the
> same or very close via the independant processors as all imputs will be
the
> same or similar and the firing of the shutters from the common power of
one
> camera will tend to sync both if there are minor timing differences (small
> supply voltage drop). These differences should be zero to 1/2000th in
> practice.

WOW - that's perfect synch - (0-0.5ms), Robert.  What a great result to aim
for. However, the above is based upon what one is "hoping" to get in the way
of a result, not on clinical trial and error or other criteria.  Please keep
us informed on your progress and especially what your tests indicate when
the job is completed.

My own testing indicates that your independent processors and their
independent mechanical shutter mechanisms are no where near as "very close"
as you appear to suspect.  I have found that accepted manufacturing
tolerances
(+ & -) can add up to several milliseconds unless you are both very lucky
and you do everything right.  If I were a betting man, I'd put my money on
the master/slave solution any day!  Robert, this is not a criticism.  I wish
you every success.  However, it is a considered observation.  Maybe you have
cameras selected which are already within say 2ms but I don't think you have
told us that.
Even so, my tests reveal that the end 'synch-spec' wanders or fluctuates to
a degree which I suspect precludes a result as close as you have stated.

Allan


 

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