jdramirez said:
My initial response was... 40mm if you are on crop, 50mm if you are on full frame. Since you have a 6D, I think the 50mm f/1.4 is a good option. Put a hard plastic hood on their and you should be safe from any AF issues.
I'd actually say 40mm on a full frame, "none of the above" on a crop body. I own the 40mm. On my XTi, I'd describe it as a good portrait lens. I really don't find it to be wide enough to use as a walk-around lens. As always, personal tastes vary.
Just for fun, I used sqlite to dump the focal length of every shot in my Lightroom database, then ran a histogram on the data.
| 10mm | 2406 |
| 11-30mm | 10518 |
| 31-45mm | 2582 |
| 46-60mm | 2376 |
| 61-120mm | 4262 |
| 121-600mm | 2130 |
There are two obvious hot spots around 10mm (2,406 pictures at full wide on my 10–22) and 17mm (4,195 picture at full wide on my 17-85). I took 6,526 pictures in the 16-20mm range. The median is 28mm. The mode is 17mm. Standard deviation is 69.02.
Obviously YMMV. Widely.