X1D / CFVII50C flash and electronic shutter

[ALAIN]

Hello,
I have just made a 2-way remote control system: one instantaneous for the sensor in electronic shutter, one delayed for the synchroflash.
Everything works perfectly with an exposure time of 0.3 seconds.
The big question is that I do not understand how it is possible to have this result: an image perfectly exposed over the entire surface of the sensor, while the flash time is very short!
In fact, I think there are several well separated phases but I would love to have your explanation.
Beautiful pictures to all and see you soon,
Alain (from France)

[dece]

As long as your flash starts after the last sensor line "scan" has started (that would happen at release time + some delay + readout time = at least after 300ms) and ends before the first sensor line scan stops: the whole image will be exposed...

see
... https://www.vision-camera.nl/FAQ-ROLLING-VS-GLOBAL-SHUTTER ...
(the last schema, under "3.How to avoid?")

"readout" time is the time to start (or stop) all sensor lines acquisition/scan, as long as the flash take place in between; all image will be correctly "covered" by the flash.

To have some period of time where all lines are "scanning" at same time, the exposure time should be at least longer than the 300ms readout = at least longer than 1/3s (ok for flash photography in a dark setting).
If the exposure is shorter than the readout time it means there is no period of time where all lines are "reading" at the same time; it's in that case that the flash could not expose the whole image.

You've basically confirmed the "theory" and by-passed the problems
What did you use to build your remote control system?


cheers