условиях: http://www.canonrumors.com/reviews/ef-70-300-f4-5-6l-is-review/
И второе мнение, тоже весомое:
http://ericmeola.blogspot.com/2010/12/canons-new-70-300mm-l-lens.html
Besides being the sharpest zoom I have ever used—whether from Canon or Nikon—there is no visible barrel or pincushion distortion at any focal length, nor is there any chromatic aberration. And yes, shooting at f/13 should be way beyond the "diffraction limit" of the 7D's 1.6X sensor. So much for theory.