It's interesting that you can take a lot of lenses and it's arguably not that difficult to put a K mount or at least an M42 mount on them (Olympus, Nikon, Canon, etc).
So where do you draw the line? I'm sure ivanvernon would vote for his Canon 55 1.2 as the best Pentax lens ever
But most of us will never get to use something like that.
Originally posted by Clavius Well the Sigma 8-16 can easily beat the DA 15 ltd for sure. It's a lot sharper, especially in the corners. I still think it's weird for a prime to be less sharp then a zoom... which goes even wider! Then it was also cheaper, and much more quiet.
Does the 18-35 beat the beautiful color and microcontrast that makes the DA 15 such a loved lens? I've yet to see proof of that.