[Berrakovic]

I followed this guide Pentax Wireless P-TTL (Part 2) |Photography Rulez to set up my sigma 530 DG Super to be used in wireless mode.
It fires off and works as i think it should work. The only problem is that the built in flash keeps on going off when i have turned it off as described in the guide. I thought that the built in flash would go off and start the external but not be in the exposure.
Anyone that knows whats wrong?

[flyer]

Nothing is wrong. The camera flash sends light signals to the Sigma flash to let it know how much power to output and signal it to fire, but those flashes are sent a fraction of a second before the actual shutter action. In other words, they're out of sync, so they don't have any influence on the actual picture.

[mattdm]

It fires off and works as i think it should work. The only problem is that the built in flash keeps on going off when i have turned it off as described in the guide. I thought that the built in flash would go off and start the external but not be in the exposure.
Anyone that knows whats wrong?

There's a custom menu setting on the camera where the built-in flash can be toggled between "master" (contributes to the exposure) and "controller" (no meaningful contribution to the exposure). In either case, the flash will still be there, but in the second one, it'll be so slight it won't affect the output. (It also doesn't seem to trigger blinking in my subjects when used that way with an off-camera bounce flash.)

[Berrakovic]

There's a custom menu setting on the camera where the built-in flash can be toggled between "master" (contributes to the exposure) and "controller" (no meaningful contribution to the exposure).

Thanks a lot for your answer! This is the first time using an external flash, so i don`t have much experience.

I have chosen the built in flash to be the controller. But i still think that the built in flash shows in the picture. If i take a picture and point the external flash from the object and only point the built in flash against the object then it should not be any light on it? (is that a good way to test it?)

And sometimes the Sigma flash fires of when the built in flash helps finding focus, but that i think of someting that could happens with this system. Right?

[SOldBear]

I have chosen the built in flash to be the controller. But i still think that the built in flash shows in the picture.

That's correct. When you set the built-in flash to be the controller, it still fires during the exposure, but the light output is low so that its contribution to the exposure is insignificant.

If i take a picture and point the external flash from the object and only point the built in flash against the object then it should not be any light on it? (is that a good way to test it?)

As stated above, there will be light on the object from the built-in flash. The light output of the built-in flash is low, but it is there nonetheless.

Take a photo of your setup in front of the mirror. You will see that the built-in flash does fire during exposure.

And sometimes the Sigma flash fires of when the built in flash helps finding focus, but that i think of someting that could happens with this system. Right?

That should not happen. But I have no clue.

[Berrakovic]

Take a photo of your setup in front of the mirror. You will see that the built-in flash does fire during exposure.

I have done exactly that, and there is light from both the external and built in flash. Thats what made me wonder, but thats alright then?

[mattdm]

And sometimes the Sigma flash fires of when the built in flash helps finding focus, but that i think of someting that could happens with this system. Right?

I experienced this problem too, and it was the deal-breaker for me — the most significant of of several issues which made me returne the Sigma flash and buy the Metz 48 AF-1 instead.

Metz's reverse-engineering of the wireless P-TTL protocol appears to be better than Sigma's, since the problem doesn't occur there. It also doesn't happen with Pentax brand flashes.