Ken Rockwell likes the 20/2.8 with its "intelligent field curvature". (*snicker*) But Ken is a weird type. Most of the other tests I've seen (the Photozone itself, SLRGear, TDP and the now-defunct SLRLensReview.com) seem to indicate that it'd be better not to bother. To quote the SLRLensReview on this one:
Re: the 20/2.8 again, I would've probably chosen the 17-40L instead if I had been lacking money for something better. Although, if I had been wanting financially, I would not have gone FF at all because good glass is mostly expensive in that land - things are usually cheaper in the APS-C realm.
Quote:The lens performance around borders on a full frame 5D was outright miserable - wide open or stopped down, borders were basically iffy throughout the entire tested aperture range. Image quality in the center was the only bright spot here - at f/2.8 center was reasonably sharp and quality improves once you stop down, reaching a respectable level by f/5.6. Conclusion? Performance of the lens on a full-frame body only complicates things - should you ever go after a lens with a decent center and lackluster border quality?http://slrlensreview.com/web/reviews/can...ens-review (That site hasn't been updated in ages but old reviews are still accessible. It was the only site I've found to carry a review of my favourite Sigma 14mm f/2.8, that's why I liked it. )
Re: the 20/2.8 again, I would've probably chosen the 17-40L instead if I had been lacking money for something better. Although, if I had been wanting financially, I would not have gone FF at all because good glass is mostly expensive in that land - things are usually cheaper in the APS-C realm.