How much light does CNTL flash "spill" into scene?

here a set similar to yours I think Check the exifs on them and i'll post my comments in a few minutes...

Baseline shot but it's dark here with the lights out... it's like your eyes stopped working



This was shot at ISO 160 which made the flash amp up quite a bit.

look what happens at ISO 400

and this mess in in HSS mode at 1/250

There were all in matrix metering and M mode and all the other settings aside from ISO should be the same in all 3 shots above and the shutter speed in the last one.  my last test in the other thread was also matrix but in S mode.

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