I think the skill lies substantially in knowing when to let the camera work things out.

Because it's sophisticated and highly capable?

Setting, say, ISO 1600 in one mode, and forgetting that it won't be that in another?

Setting ISO 1600 when in User mode, and forgetting that it won't remember it at next switch on unless you save it explicitly?

Leaving the flash compensation at -2.

I've done all three of these, several times.

Not as plausible as your list, though, John, if there weren't any usable shots at all.

Sorry, just raising my voice a little... thought he might not have heard the question the first few times

Well you haven't said what the K10D didn't or couldn't do, except "perform". And you haven't said what the other camera did do, except killed the K10D, which sounds a little unkind. And you haven't given any examples of pictures produced by either.

So it's a little hard to tell what the issue is.

I knew what he meant too. But it had to be done...

One day I hope to use a word he doesn't know, too.

I think you meant this, George:

The length of time a shutter is fully open varies from camera to camera, but with a focal plane shutter is usually no less than 1/250, and generally rather more. This is the "flash sync speed".

I was assuming that the curtains themselves travel across the frame at about the same speed irrespective of exposure, once it's shorter than the sync speed.

So they'll travel at the same speed, thus taking the same total time to get across, at 1/4000 as they do at 1/180.

Of course, at 1/4000s they'll be much closer together, as I said, so each part of the frame will only get the 1/4000.

If my estimate of 20 flashes is right, then it's 20 flashes in 1/180s or thereabouts, not 20 flashes in 1/4000s, but the precise timing still amazes me.

And it works with two flashguns, and wirelessly, as I understand it.

The more I think about HSS, the more it boggles my mind.

The K10D has a flash sync speed of 1/180, and with HSS it can sync all the way up to 1/4000, AIUI. At a shutter speed of 1/4000, presumably the gap between the curtains is only about 1/20 of the frame as it crosses the sensor.

So does that really mean that the flash must flash about 20 times during the exposure? Presumably the exposure itself must last about 1/180s in total, but even so.

And how accurate must the timing of the flashes be, so as not to miss bits, or expose parts more than once?

Have I missed something, or is it really that precise? I can feel some tests coming on...