Before I ordered the 24-70f/2.8L, I had read just about every review, including the many threads that had pointed out the existence of "bad copies" of this lens. To be honest, I wasn't sure what to make of them. Unfortunately, when I received the first copy of this lens, I realized that there are indeed lemons in circulation. I returned it for another copy, which is much better.

This is *not* a carefully controlled comparison, but it clearly demonstrates the differences. All pictures were taken in raw, and processed with C1LE with just a slight (default) amount of sharpening. The full pictures are downsized to 1024 pixel width. The crops are at full 100% pixel resolution. All jpegs were saved as high quality.