Originally posted by Outis I'm watching this thread with great interest-- I'd love to get a pancake as a walkaround lens, but in ratings the sharpness of the 21mm is never as good as the 15mm or the 40mm. But people seem to love it. I'm curious--what causes the disparity?
I think there may be a number of sub-par DA21's in circulation. The first one I had would not focus to infinity. I sent it for repair, and while the problem was fixed and the center was sharp, the edges were very soft. Later I obtained a second copy and find it to be very good.
The 21 has a high level of distortion, too, and while Photoshop & DXO and other programs correct it easily, that was an issue with older software, even though in the field the distortion is not always an issue - in fact, sometimes I prefer the uncorrected image.
Looking in the lens database, I see both the SMC DA21 & SMC DA15 currently rate a 9.1 for Sharpness. My own impression is that the DA15 is a bit more contrasty than the DA21, which increases the impression of "sharpness".
While IMO the DA15 is a slightly "better" lens - its more special - I would pick the DA21 to be my walkaround lens, if I had to choose between the two.