EDIT-Posted some photos taken with the lens. I know, the noise levels are terrifying. Hi- Behold, my lovely rental! This baby from Lensprotogo is a 70-200mm 2.8 IS 'L' Lens. After putting my camera around my neck, I can see where all the bad jokes come from. Here are my few questions, please keep in mind this is my first IS or 'L' lens. 1: What's the difference from IS mode 1 and 2? 2: What's does it mean to focus at infinity? I've heard this term before. \ 3: What does the switch that says 1.4m-Infinity and 2.5m-infinity mean? 4: Why does the focus ring work normally even with AF on?