Originally posted by PENTAX LEEBO There is not much difference between the two. The 31mm is only a stop faster and is bigger than the 30mm really like these comparisons as I don't have the 31mm to do this. Luckily I don't mind using manual lenses thanks for the comparisons
A 28/2 and 31 would be interesting.....I'm only doing the 30/2.8 v's 31 to get a picture in my head what I'll be giving up when I only have the 30 with me (as part of my 3 prime manual kit). I suspect it will be more abrupt on the focus transition (you can see this with the book photo), more flare prone and obviously you don't have 1.8! The slight loss in contrast is pp'able.....so the bokeh on the 30 will be the main issue I think (a 31 strength).
I chose to buy the 30/2.8 over the 28/2 mostly because of size....as i really wanted a 30/50/85 smallish K kit and the 50/1.2 and 85/1.8 are already bulky and heavy....I had a certain bag in mind for them as well.....and I reckon (given my usage) the 30 won't be used as much once the FF is here.....(based on my current APSC use of my 31 and 21)..... the 50 and 85 are bokeh kings (queens?) anyway.