Alex, FWIW, below is a list of the Photodo tests for the Canon zooms v. Sigma zooms. Compare for yourself and see what may be best. Check out F4 which is a stop down for the F2.8 lenses and note how well they do. Also, interesting note that at 200mm the Sigma is best of the lot wide open. Also at 135mm at F8, a setting ideal for portrait sittings, the Sigma is every bit the equal (or better) than the others.
EF 80-200mm F2.8L weighted MTF for 80 mm: f2,8 0,76, f4 0,83, f8 0,83 EF 70-200mm F4L weighted MTF for 70 mm: f4 0.80, f8 0.81 EF 70-200mm F2.8L weighted MTF for 70 mm: f2,8 0,75, f4 0,80, f8 0,78 Sigma 70-200mm F2.8EX weighted MTF for 70 mm: f2,8 0,73, f4 0,76, f8 0,75 EF 80-200mm F2.8L weighted MTF for 135 mm: f2,8 0,78, f4 0,84, f8 0,85 EF 70-200mm F4L weighted MTF for 135 mm: f4 0.80, f8 0.86 EF 70-200mm F2.8L weighted MTF for 135 mm: f2,8 0,80, f4 0,85, f8 0,86 Sigma 70-200mm F2.8EX weighted MTF for 135 mm: f2,8 0,76, f4 0,84, f8 0,87 EF 80-200mm F2.8L weighted MTF for 200 mm: f2,8 0,75, f4 0,81, f8 0,83 EF 70-200mm F4L weighted MTF for 200 mm: f4 0.81, f8 0.82 EF 70-200mm F2.8L weighted MTF for 200 mm: f2,8 0,73, f4 0,79, f8 0,82 Sigma 70-200mm F2.8EX weighted MTF for 200 mm: f2,8 0,78, f4 0,81, f8 0,81 * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
