I just bought a second-hand em5, and am trying to decide what lens/lenses to get. If I sell off all my canon equipment, I figure I should end up with ~$500 to spend. I already have a few vintage lenses (a 30mm f2 pentax, 50mm f1.4 canon fd, 28mm fd, and a few fd zooms in the 35 - 270 range.) I also have a canon mount Rokinon fisheye that I plan to trade out for the m43 version. So... given that, and given that you probably won't get to buy any more lenses for at least a year after, what would you buy, and why?