Originally posted by pschlute The 31 and 77 have especially pleasing bokeh when used at or near wide open. But like many other posters, the aperture needs to suit the subject. Here are two pictures from a recent K1 + 31mm day out. One at 1.8 and one at 6.7. Can you tell which is which ?
This pretty much sums up my response, great pictures by the way, both of them! First is 1.8, and second is 6.7. (Don't mess with my mind by telling me it's the opposite xD)
I only have the 43mm, and I've posted a thread recently stating how I use it exclusively for documenting family, but I still follow the same rules of choosing the right aperture for the subject at any given time. I keep it wide open or close to for a single individual, down to 2.8 if it's daylight, maybe a little smaller if there's a group, and then of course landscape or travel would be smaller, but I have only taken maybe one non-family shot with it so far
It definitely has a unique look wide-open, but I think it serves a good purpose even stopped down because of it's size, focal length, and option for bright apertures, so I don't make any exceptions to my rules just because it's a limited lens.