Matt and the others THANKS,

Set to manual I can get the sigma to fire at the right time, in the right way(so thats what the M is for on the K20). I can set up the shots with the dance class next week without leaving them hanging around waiting too long. Excellent.

I suppose I expected too much from the on-board technology, just hope I can turn my mental image into a nice picture now, thats always in manual mode, the artistic bit.

I'll check back here for further comments, meanwhile, thanks again.
Ray H

Cheers Matt,

I will try this spanish Manwell chap.

Or did you mean beat me or the flash with the instruction manual?

Seriously I'll give it a go and let you know

Cheers Ray H

Ok Guys, the is really good info. Now I have to fully confess my ignorance of Flash photography. First I usually and mainly shoot ariel stuff from a flexwing microlight using my K20 and the Pentax 50mm f1.4 lens which is razor sharp at F4.

I got the flash as I also shoot some of the marketing pics for the local college I work for. Now in my ignorance (HND electronic engineering) I assumed that wireless means RF, not light triggered (else why different channels?) so covering the camera pop up as a test, I expected the Sigma to fire (via RF). If the camera has a channel setting I can't find it.

Now, Mannesty, what I tried to describe is when I set the Sigma on the floor behind the test model (long suffering misses) although it was out of the framed shot it was supposed to provide a strong backlight effect (thats what I'm after). When I took several pics I could see it firing through my left eye, but it was not on during the cameras exposure. (Sigma 24-70 macro lens @ f4 Camera iso 200 Exp on X ) The picture only showing a dark front lit shot.

I also find using it in dark clubs a real pain (College sports awards presentations) finding, on a wide lens setting, an exposure that lit everything OK, when I zoomed in (Sigma 24-70 f2.8 ) for a better sports man of the year shot, the pic was very dark, so I had to stop the proceedings to reset for a properly exposed shot. (My old Olympus 5050z was never this much hassel).

All that aside I would like to get this shot of the dancer, back lit by this flash. There must be a way.

Cheers Ray H

Hi Guys thanks for the replys. Haven't had time to try your suggestions yet so here is what I'm trying to do. I want to photograph a dancer, the theatre has black curtains, I want the camera flash to light the front and the sigma to be behind and to one side of the dancers pose to give a strong quarter back light.

Experiments have shown the the sigma is firing on the cameras pre flash because when I cover the pop up flash on the camera the sigma dosent fire.
Am going to read both manuals again and try once more.
Ps The sigma always seems to under light when on the camera and I have to use about +1.5 to get the exposure correct. Is it duff??
Cheers Ray H

Hi Everybody,
I have a Pentax k20 and I bought the latest Sigma flash (EF-530 DG Super)
and after reading other posts on here I still cannt sort it out. It fires on wirless mode apparently ok, but, before the shutter opens by the look of it. No messing with shutter speed shows the sigma firing in the picture, yet I can clearly see it doing so through my other eye.

Have tried various camera and flash settings to no avail, Any ideas please?

Cheers Ray H