Quintessence 1

The opening 2.8 is capital (remember that the auto focus is in full opening, before the diaphragm closes, and its precision, speed are largely dependent). In addition, the famous 2.8 makes full use of the capacities of autofocus systems (collimators double cross): I could ascertain, very little focus failure, even in fast capture conditions (street-characters) after a short period of adaptation to the specific reactions of the goal.

2.8 This, fast and very effective stabilization, give an incredible feeling of comfort, it "feels" the objective very bright and no need to walk. On a full frame (24x36) visible vignetting 2.8 gives in some scenes a must. While for others, it tick, but the software correction is perfect as DPP, Think DDP4 - reserved for so-called Reflex "Pro" from ESO 7F MII - without these "Libraries Obliged" where one seeks for hours - ergonomic, fast, effective for immediate processing of a photo that you want to keep natural.
Weight? What weight? Who thinks the weight when one is filled? The body adapts quickly ...
The dive, on top according DXO. This is the case. Is well known.

Finally, the Canon is very protective package, no worries, in addition there is the packaging Amazon (in my case).
Delivery within 24 hours, even in my corner lost!
Hence my 5 stars. It's rare to me.