Excerpt: Haven't had a great need for a flash unit, the on-camera flash has been sufficient. But I'm finding that the subjects I'm currently shooting require something more versatile with greater output. The AF-540 fills the requirements. Can be hot shoe mounted or positioned off-camera using it's included base or on a light stand. Wired or wireless, as needed.
Excerpt: My experience with flashes is as follows : Pentax AF280T, Vivitar 285HV, Pentax AF500FTZ, Yongnuo 460, Yongnuo 560, Sigma 530 ST DG and now the Pentax AF-540FGZ. I've tried a bit of everything.
Pros: Powerful, offers just about every control possible
Excerpt: A good powerfull flash, which matches the Pentax bodies brilliantly. For easy photography it works very good: TTL techniques makes sure you get a well-lit image. Tilt and swivel head makes it possible to to use the reflective walls/ceiling and more depth in the image. That was the reason to buy a 540 (and not 360 instead, although I did not need the enourmous power of the 540).