Well, this is a bit disappointing. After trying a few lenses with little success (except for just one new DA 35mm f2.4 from Adorama,) I ordered a fresh new 50mm 1.8 from B&H after reading such great reviews. To my dismay, this one also looks like a lemon.. I'm losing confidence in buying lenses now.. especially used ones due to the defective rate that I've experienced. Am I just out of luck with Pentax lenses? I've never had this problem with Canon including 3rd party lenses. Maybe just a luck, but it's pretty weird. OK, here's my quick history from this January when I switched from Canon T2i to Pentax K-3 with DA 35mm.
I ordered a used Sigma 17-50 on eBay and it turned out to have bad focusing in some focal lengths, especially near 35mm, so I had to return it. Next, I ordered a 40mm Limited here in the forum, and found the lens was decentered so I had to return it. Next I purchased an FA 50mm f1.7 on eBay and found it front focuses on distant subject while focusing right on close subject or vice versa, so I had to return it. And NOW, having been tired of being disappointed by used lens, I ordered a fresh new 50mm mentioned, and this one suffers from focusing and even -10 adjustment, it front focuses! It hunts and hunts for auto-focus and sometimes even can't focus.
Now I have to return this one again. Would my camera be a culprit? But it produces lazor-sharp images with DA 35mm with +3 fine adjustment. Also, it worked well with Sigma 17-50 except for 35mm range, so I doubt it. I really wish I could settle with this 50mm but now I have to return it again. My wife thinks I'm getting crazy-buy and return, buy and return..
Does anyone have an experience like me? i'm kinda losing confidence in buying lenses..