No apology necessary. AFAIK that's how all camera based wireless flash controllers work.

At least it does work and if you wanted to illiminate that camera flash from your composition you'd have to use radio or IR wireless triggers/receivers.

The communication system between the 2 flashes is a series of light pulses from the flash tube, not radio or IR.

The 'instruction' for the wireless slave flash to fire once the leading shutter curtain is open, and before the trailing shutter curtain has started to move, comes from a pulse (or series of pulses) of light from the onboard controller. Like it or not, that light illuminates your subject in some small way. With a human subject, you may even see it refelected in their eyes.

The only way to overcome this is to use a hot shoe mounted radio trigger and flash mounted receivers . . . . or wires.

Sorry Chris, but that is the case. Both flashes fire at the same time in any wireless mode. When the onboard is used as a controller, it still fires, but at a reduced output.

Take a wireless shot in the mirror, that'll prove it to you, you'll see both flashes light up.

PS: I didn't need to read your post again. I knew you were wrong the first time I read it . . .

When the built-in flash is used as a wireless controller, it DOES contribute a very small amount of light to the composition. Fire it into a mirror, you will see the flash in the resulting image.

True.

Not true. The built-in certainly does fire because it is that small flash which triggers the wireless slave.
In the normal course of events, when you press the shutter button:-

1: Leading curtain moves
2: Flash fires when whole frame is exposed to light
3: Trailing curtain moves

At 2: above, the onboard flash fires to trigger the wireless slave.

www.warehouseexpress.co.uk sometimes have some amazing bargains. I got hold of a brand new Pentax fit Sigma 135-400mm lens from them for less than £200. C&N versions were nearly £500 at the time.

That was however at a time before the rise in popularity of the Pentax brand.

Pete,

That sliding menu system just doesn't work very well. If you move the mouse to the right, over landscape pics, then back to natural pics, it slides another menu under the mouse cursor, then moves to that one. Irritating in the extreme.

Pics look good though.

Cheers,

As far as I am aware, it is only the built-in flash which strobes to assist focus. Any flash having a purpose designed focus assist lamp will use it, not strobe the scene.

It has been noted elsewhere under IR photography topics that the K10D is much less sensitive to IR light than the *istD was due to the filter over the sensor. Maybe this accounts for it not 'seeing' the grid pattern from AF assist capable flashes.

Surely . . . you need a K9 . . . sorry, couldn't resist.
Fact, your camera cannot function properly in the dark, any more than a cat can see in the pitch black, a common myth.
Fact, your camera needs a bright enough light source in order to achieve focus lock because it needs to 'see' some contrast in the surfaces it's focussing on. Without this, you need to use manual focus, but you can't see anything to focus on.
Fact, you need a bright enough light source to capture an image.

Now, if you are in a field, at night, with lots of green grass, a red light is useless for focussing because green surfaces do not reflect red light. That's probably why you may have had more success with your Fuji 9600.

A simple remedy is to use a torch for AF and if your flash doesn't fire as a slave, either it's not compatible with your camera, something is broken, or you haven't set it up correctly. Chances are you set the flash too far away from it's triggering source which wasn't bright enough to trigger it.

Does the flash fire as a slave OK in indoor lighting? Was something obscuring the slave sensor?

This info begs a question . . .

Does Pentax design/manufacture for Samsung, or is it Samsung designs/manufactures for Pentax.

If the former, how on earth did anybody get permission to release this Samsung info ahead of Pentax?

CMOS sensor too, CCD ditched.

She missed.