Someone on DPR linked to a Sony webpage where they illustrated how the A9-III deals with pulses from two Sony flashes at high shutter speeds, and Sony gave guide numbers in tables, and I took those guide numbers and squared them, then divided by milliseconds of exposure, to create a metric proportional to absolute flash power at those shutter speeds, relative to ambient light, like sunlight. As you can see, at some higher shutter speed, each flash on the A9-III gives about 3x the flash-2-ambient ratio as at the traditional 1/250 max sync:
Jan. 24, 2024
