Yep...great comprision Matt....thanks a lot
I've recently switched from a Nikon system to Pentax....so my standards on flash functionality is pretty high
A little frustrated not beeing able to get my Sigma EF-530 DG ST to work properly on my K20D. I't works OK and seems to measure correctly in TTL-mode (P-TTL?) when I'm bouncing the flash and using the wide dispersion panel. When I'm using direct flash in TTL-mode it overexposes terribly with totally blown out pictures. The same regardless of mode on the camera (Green rectangle, P, Av, M...all give the same result). Auto-ISO or fixed ISO doesn't make any difference. It's worst in focal lengths from 50 (70) and upwards ergo when the flash gives the strongest and most focused light, but also occurs to a lesser degree on shorter focal lengths. It's also worst at closer distances. I'm wondering if the flash is blowing away at full effect all the time!!? Different apertures in AV-mode doesn't make any difference (difficult to tell when the pictures are blown-out all the time).
What causes this??? Is the flash faulty in some way? Is it the lens (Sigma EX 18-50/2.8) not communicating properly with the body (don't think so since exposure without flash or with the built-in flash is just fine). Is it the flash that's not able to quench the output quick enough when low outputs (eg close distances) are needed?
It's not a big problem since I very rarely use direct flash...I bounce most of the time...but it would be nice to know that the flash-system (P-TTL) are be able to give correct exposure even when using direct flash in case you wan't to use it sometimes (for example macro shots on insects). And since the Sigma-flashes don't have A-mode (built-in sensor of their own) you're stuck with using TTL (or cumbersom manual output)
All help greatly appreciated! Sorry for the "wobbly" "swenglish" (I'm from Sweden
)
Kind regards / Matti
Last edited by The Photo-Vet; 07-23-2009 at 03:46 AM.