Canon Camera Hackers Manual page 228

If you don't want to do any soldering, you can acquire a ready-made
unit. For example, gentStereo from Gentles Limited allows you to control
two or more cameras simultaneously. Similarly, the SDM Canon USB remote
from digi-dat can fire up to 12 cameras simultaneously. Or you can use the
Ricoh CA1 remote control with a mini-USB/mini-USB Y-Cable Charger
Adapter.
In any case, when you want to trigger two cameras synchronously, you
must enable the synch mode on both cameras with
Synchronization > Enable synch. The SDM header line will display "Synch:"
followed by the specified delay value (see below). From now on, you should
operate the camera only via the remote control. Pressing the shutter but-
ton directly will disable the sync mode!
Calibration
Exact synchronization is only achieved when both cameras have exactly
the same delay time between USB signal and shutter release. Two cameras
of the same model should have approximately the same delay times, but
when using different models, differences in delay times can be consider-
able. Fortunately, you can assign a different delay time to each camera in
ALT > MENU > Stereo > Synchronization
Finding the right delay intervals can be tricky. If you still have a CRT
monitor (or if you can borrow one or cheaply pick one up at Ebay), you can
use the Camera Sync Tester from
to determine the differences between the delay intervals of two cameras.
If not, you can simultaneously shoot the turntable of a power drill with
both cameras. If the drill turns with 3000 rpm, a difference of one degree in
the position of the turntable is equivalent to a delay of 1/18,000 sec
(0.06 ms). A power hand blender with its higher speed
be even better. By overlaying both pictures, you can determine the differ-
ence between the two cameras quite precisely.
Mounting
The simplest solution for joining two cameras is to mount them on a plain
bar. The bar can have a simple design, and by default the lens centers are
aligned to the same height.
A better mount, however, is the Z-frame. The cameras are mounted
side-by-side with one camera turned 180°. The advantage of this frame is
that—because most cameras are asymmetrically built—the lenses can be
mounted closer together, resulting in a lower near limit. Typically, Z-frames
are built with a special camera model in mind so that the lens centers are
aligned.
ALT
> User delay.
www.3dtv.at/Knowhow/Synctest_en.aspx
> MENU > Stereo >
(Figure 4-23) would
7.7 Stereo photography
219