I need your help! I'll be purchasing a new lens soon for many applications, the most immediately pressing being a trip to Africa. I am considering the 135L and the 70-200L Each has its own advantages. Both are known for excellent IQ. The zoom would work well for travel, however that won't be the exclusive use for this lens. I'll also be taking my Canon 20mm f/2.8 and the new Sigma 50mm f/1.4 (because Canon doesn't seem to care about this lens anymore). I'll also be taking a FF Canon Digital. Please Advise!