[d.bradley]

I have a 17/4 Fisheye takumar and really love it. But I've found a 15/3.5 SMC-K at a local shop, and they're selling it for a song.

There are HUGE differences in these lenses. The 17/4 is basically a pancake lens, which is fantastic. IQ is very good below f5.6 or so, and frankly I love the fish.

By the time you factor in the fisheye effect, the 17mm probably has a similar (maybe wider?) FOV than the 15mm. The 15 is HUGE with a massive and bulbous front element. It looks crazy mounted on the K10. There was mention of the 15/3.5 in the 'legend' thread I started a few days ago, and as I said this thing is a steal at the price they're asking. Reviews seem positive, but I am not sure I could ever part with my fisheye! I'm considering picking up the 15, doing a shootout / comparison review (I wonder how many people have had both the 15 and 17 in their possession at the same time :P) then selling the runner up!

[and]

deffinetly pick it up, you can sell it on ebay and make money off it if you decide not to keep it.

[jamesk8752]

The 15/3.5 is not an outstanding performer on a digital SLR in my experience. If it's cheap, go for it; but if it will cost you more than $500 you are better off buying the DA14/2.8, which has significantly better contrast and sharpness.