Taking exceptional hand autofocus exemplary rapiditée! On the emblem that goal does not disappoint! I had read rave reviews and some a little less. After, having used it in diversses conditions this goal fulfilled more than his "quality contract"! The construction is very well made! nothing to complain about when to ergonomics! Lightweight and compact, it offers outstanding grip. It is so stable that the shooting is optimized .. It allows to fully exploit the potential of the 12.2 megapixel sensor of 450 D. 17 to 40 mm, even at full aperture the consistent quality of this lens lets you easily forget the idea of the dive, both at the center and that the edges of the image, because this side, even to f4 (fully open) the results are very good level, see even excellent. That said, it is therefore that this objective f5.6 you "guarantee" a superb image contratée and held high !!! 17 mm, of the distortion of large angles are contained. Alot of people, I suppose hesitate between investing in such an objective or buy a box with a powerful CMOS, 15 see 18 mega pixels by associating a more basic ojectif. Remember to follow a certain logic, 17-40 associated with a 12.2 CMOS will make you much happier that a large sensor associated with an entered target range or midrange. Also, the most important is to consider the final rendering of an image because with CMOS rich in pixels, you can even with very decent goals end up with a final image rendering "soft". In any case whatever phototographiques your choice, I highly recommend the 17-40 f4 that outside its its price (for a moderate L series), is well worth the 5 stars .. a visual rendering "flawless" to me sweet! Go there you will not regret it!
