As with many OEM flash and camera combinations, and even with Auto ISO 800 or 1600, the shutter speed chosen is often very slow - for example 1/15 or 1/30 sec. I do not understand. I use this for indoor photography and prefer AV mode, but even with jitter reduction I don't trust it to produce really sharp images at these slow shutter speeds. So I have to use TAV mode set to 1/100-1/160 and f6.3-8.0 with auto max ISO at 800 and it works fine. In P or TV mode, it automatically chooses the widest aperture, which rarely delivers a comparable IQ. a few stops down. Otherwise, the build quality is very good and solid. It's a small flash that I really like on my K5 II or K30 and has enough power for my needs. It features HSS, master/slave modes, a nice backlit LCD display and it's very easy and quick to switch power supplies when needed. I would have liked an additional diffuser. Would have given 5 stars if the slow shutter speed hadn't been chosen.