The 28 mm focal length lens was one of my favorite walk-around lenses when I was shooting film, so I decided to get the AF version of this lens. I wondered for days whether I should get the f2.8, or the f1.8 version. Since I already have the 16-35 mm f2.8 (L) series(Big & Heavy), I decided to get the f1.8 version despite the tons of negative online reviews. The lens which I purchased from eBay came in the mail 2 days ago. As advertised, there wasn't a scratch on it . This is really a beautiful lens, with a gold ring, silver lettering, a Distance Scale and faded black lens cap. I quickly unpacked the lens and slapped it on my Canon (FF) 6D. Unfortunately, when I hit the shutter button half-way to focus, all I heard was a thunk ? I kept trying to get the lens to focus, changing the shutter speed, ISO and aperture but nothing worked ? I switched to MF from AF, but the lens would not focus ? Disappointed, I contacted the seller and asked for a Refund which he agreed on. The next day I decided to lightly tap the side of the lens with a butter knife and Voila ! the lens started focusing like there was no tomorrow ??? This is a great lens ! slightly sharper than my 16-35 mm, but not as Contrasty. What got me, is that even at f1.8 this lens is sharp and only slightly improves once you stop down. I'm not sure why it would not focus when I pulled it out of the box, but it sure works now. Right now I'm thinking about sending it to Canon for a check-up and calibration, but why not just leave well enough alone ?