And now, the whole adventure that was porting the CHDK comes to this,
taking synchronised images from multiple cameras at once. But it's
still not that simple!
First we need some more hardware that will trigger the cameras:
Build after
schematics on CHDK wiki, the voltage trigger works.
But
now it needs to be tested with two cameras, to see if the image
acquisition is synchronised, so we need one more piece of hardware:
A true scrap heap project composed of an unused electric motor from a
model plane, some spare electronic elements, a CD holder from an
ancient MacBook's CD drive and a brand new DVD which was drilled trough
so a LED and a battery was mounted on it.
With this the
synchronisation wheel came to be. By using the known exposure values on
the camera and tracing the light trail made by the LED, the rotational
speed was calculated to about 10.36Hz.
Now with this information the synchronisation between the cameras can be calculated:
Taking the same picture with both cameras at the same time with the
trigger, the angles from the start and en of the light trail can be
measured and compared.
So far, the exposure time was the same and
worst calculated delay between the cameras was 0.3ms. Not bad, but this
may still vary a bit, since so far it has only been tested with few
pictures and on one set of settings.