Wireless flash, Pentax istDS, AF360FGZ and Sigma 500 super

Can somebody help me clarify the wireless operation of these. I think the descriptions I have found are contradictory and uncomprehensive.

For Pentax AF360FGZ the *stDS manual p 153 says it can operate as slave and as wireless.

P155: Using in Wireless Mode
"Shoot using the flash without connecting the camera and flash with a cord
by using two AF360FGZ units.The High-speed sync mode is also available
in wireless mode."
Does this really mean that I need two 360s to operate wireless?

The description for the Sigma 500 Super says:
"4. Wireless-slave-flash functions:

The EF-500 DG SUPER provides the TTL wireless-slave-flash functions, which allows the flash to be moved to a location away from the camera for operation. The TTL wireless-flash function enables the control of multiple EF-500 DG SUPER units while preserving the automatic TTL control function. The model for Sigma, Minolta and Pentax uses the camera's built-in flash for signaling, and makes the EF-500DG SUPER located away from the camera to fire."

I would like a flash that I can locate away from the camera, use a softbox or umbrella and have the flash controlled wirelessly from the camera. According to the descriptions above, this should be possible with one Sigma plus internal flash whereas the Pentax alternative needs two 360s.

Is this really correct?
--
Regards
Lennart

I'm sure that's not correct.

I use the *ist-D with the AF360FGZ in wireless mode. The pop-up flash signals to the AF360FGZ and fires it remotely. Works a treat

You can use two AF360FGZ's - one on the camera and one off. I think the manual is just pointing out the creative possibilities if you have the funds

(While on the flash subject, I have just ordered an Interfit eFlash which looks really nice. I'm really after it's big brothers the cyberFlash units. Very very slim units that don't need softbox or umbrella.... I'll let you all know how it performs when I get it)

Matt

My understanding is that the 'wireless' functionality is even cleverer than that in that P-TTL mode is also used. When setup correctly, the pop-up flash fires and triggers the off-camera AF360FGZ at which point the camera does its sums and works out the 'perfect' exposure. Then the whole process is repeated using the cameras computed settings and the image captured. To me this is not true wireless operation, more enhanced slave mode. That said, I believe the AF360FGZ can work with another AF360FGZ in true wireless mode in that the two guns have to be on the same 'channel'. I have only just received my first AF360FGZ and am still finding new functions to explore. I have it mounted atop my *istDS.

You write "My understanding....." Can you confirm (have tried) that the pop-up flash can really control the exposure by controlling the flash of the off camera AF360 with a Pentax *istDS. According to some information there is different behavior in *istD and *istDS.

Regards
Lennart

I can confirm that when using the AF360FGZ in wireless mode off-camera with my *istDS, BOTH flashes trigger twice. Again, my understanding is that the camera and popup flash is in P-TTL mode where the flash(es) fire once for the camera to do its measurements (evidenced by visible flash in viewfinder with mirror down), and then a second time for the actual image recording. The ofcamera AF360FGZ in slave 2 mode can be set to either 'A' or 'M' flash modes. This operation is actually very easy to prove. Place the AF360FGZ in front of the camera with the flash head pointing at the lens. Take a photo in Auto-Photo mode and watch the off-camera flash in the viewfinder. When you release the shutter, 1) you will see the slave flash fire in the viewfinder because the mirror is still down for the first flash, and 2) you should record a very bright flash image in the shot when the camera records the shot. Again, I believe the camera and its popup are in P-TTL mode and the slave is in 'A' or 'M' mode but the whole shot is processed as P-TTL.

This still does not confirm that that the Sigma can be controlled. The Sigma can unduobtedly work as a slave and fires each time the pop-up flashes. The pop-up flashes once and measures the light, than adjust the pop-up flash. The second flash also triggers the Sigma but cannot to my understanding control (that is adjust the amount of flash) the Sigma. This is what I have concluded from reading in http://forum.digitalfotonetz.de/viewtopic.php?t=11457 (in German).

If you could confirm that the amount of flash from the Sigma can be controlled by the pop-up flash I would be very happy. This could easily be tried by using two widely different aperture settings. The influence of the pop-up flash must be small, e.g. use aperture settings of 5 and 10 at a distance of 5m at ISO 200.

Regards
Lennart

According to the post at digitalfotonetz.de and also at dpreview there is a difference between *istDS and *istD. The *istD can indeed control the Sigma wirelessly, but not the *istDS.


Lennart

Someone out there will know more than me, but I don't think the sigma will work in wireless with the camera or 360FGZ, simply because to my knowledge it wont work in P-TTL mode which requires a pre-flash...this pre-flash to my understanding will set off the sigma before the exposure flash. A) this will completely confuse the cameras metering, B) the flash will not charge again quick enough for the 2nd fire.
That's just my thoughts for what they're worth.
I haven't used the *istDs, just the *istD. Also, yes I'm 100% sure the 360 will shoot wireless on it's own (2 are not required).
Hope this helps.