I used an oscilloscope a while ago, and found the same thing. The
flash starts at about 10-12 kHz, and then the frequency increases to 18
kHz or so. As you might expect, the brightness of each "flashlet"
decreases over time since the capacitor is being discharged, but since
the frequency is increasing the overall brightness must remain
relatively constant. I don't know if this is from the Oly designers
being very clever, or just a happy coincidence of how each flashlet is
triggered (or a bit of both). Also, the flash does stop pulsing when
the second curtain closes, thereby causing the recycle time to decrease
for faster shutter speeds. If there's any interest, I could plot up
some of the traces and put them on the web.
Mark
Matt BenDaniel wrote:
Apparently in Super FP mode, the F280 pulses about 10000 Hertz. This
implies that the F280 would flash 5 times during a 0.5 millisecond
exposure. That does not sound equivalent to continuous lighting. For
example, with moving hummingbird wings, this could yield some
interesting artifacts.
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