I'm after some advice please. Wide angle photography appeals to me but I'm finding my MZ 14-54 Mk II not wide enough, and the Samyang is a fisheye of course. Currently I'm considering: O12mm f2.0 - but is this too close to the 14-54? O9-18mm Panasonic 7-14. Apart from optical performance, build quality is also important to me. I try to avoid lenses that are too plastic-like unless of high quality, and anything that feels a bit flimsy. Bearing this in mind, which of the above lenses would be my best option ? Thanks.