Some of them cease focusing at all in such conditions. The Sigma 14mm, the Canon 18-135mm STM at 18mm... I also think the 24/1.4L II doesn't work with extension tubes. The 16-35/2.8L II kinda works, at least at 25mm and longer, but not at 16mm.
Quote:As a poor man's alternative, could you just use an extension ring on a non-macro wide angle? Of course, you will lose infinity focus, and I suspect the small extensions needed may not be easily provided with off the shelf ones.All in all, this new lens looks interesting, if only as a technical achievement (like the Sigma 24-35/2 announced recently). I hope that Klaus gets his hands on one someday.