This is a comparatively large unit that offers full tilt and bounce functions.......
Sigma EF-500 DG ST
This is a comparatively large unit that offers full tilt and bounce functions; not only does the flash head move vertically but it also rotates on the horizontal plane, allowing for a greater choice of surfaces from which to bounce the light against. It’s powerful, with a GN of 50m@ISO100, so appears good value for money, and there’s also a built-in diffuser to increase the standard angle of coverage – up to that of a 17mm lens. It offers dedicated TTL output for several camera makes, though not all, and also has two manual settings of full and half power.
Images tend to slightly underexpose against white backgrounds, but improve with darker and mixed backgrounds. The fall-off at the standard wideangle of 18mm is obvious but this can be remedied using the built-in diffuser. However, the unit does produce a slight hotspot in the centre of the frame.
Full marks go to the Sigma for power and features, but the image quality lets it down slightly. It’s not bad for the price though.