What's that green semi-sphere plastic nob thing next to the aperture ring? I assume it's green, I'm actually total green blind, so I'm guessing!

When locked on A mode, the nob is right over the "2" of the 2.8 on the aperture ring.
I just received my used lens from an ebay auction, and it does seem as-new. Obviously, the former owner hardly used it or maybe didn't use it ever! Took a few shots yesterday. It's my first prime (have 4 zooms). I suppose it's best suited to portraiture, head and shoulders shots.
Last edited by Muse; 10-15-2010 at 09:02 AM.