Now the new object of desire: The 16-35 f / 4 L IS USM. Feel like Canon L lenses typically: awesome. It is not too light and not too heavy. The lens hood is included in the product scope! But most importantly to me is the image quality: Class! I have nothing to complain about! Beautiful sharpness over the entire zoom range. But I must say that my Sigma 24-105 provides 24-35 mm sharper and higher contrast images. BUT: According to the test charts L-lens probably really reveals its true power only to full-frame, so I already look forward to the change.
The IS is crass. With him still succeed eg 16 mm shots to 1/2 s out of your hands without shaking (to APS-C, mind you, in full formal I might even manage 1 s). The promised four more stops to come with me so ever out of the IS can compensate for movements at slower shutter speeds. When 1/15 or 1/10 I got the Sigma at 18mm and f / 1.8 has problems with sharp photos, even though I have a very steady hand.
The 2 mm longer focal length at the beginning to make itself felt also. I'm looking forward to the real 16 mm field of view at full size. This is then a wide experience, as I have not yet know it. As I gathered from tests, this lens on full-frame should only realize their true potential, especially in terms of sharpness.
An APS-C this L lens is very nice, I like it, and in my view is definitely recommended for anyone who plans to switch in time of APS-C on full frame anyway. Who certainly want to stay with APS-C and no change on next larger sensor format has in mind, really need only consider how important it a) 2 mm longer focal length in the wide-angle and b) have an excellent working IS. If both are not so important, which should definitely attack APS-C for Sigma 18-35 f1.8, the so what harmonizes with the EOS 70D, for example of perfect! Since the 16-35 a full frame lens, I can not wait, eventually it similar to a 5D Mark III to be allowed to try. If I could gain experience in such a way I'll update here.