Peter Figen wrote:
It\'s interesting to see how good some of the lenses are and how some just never come up at the edges, let alone the corners. The new 16-35 looks to be about the best of your bunch here overall, and especially at the wider apertures, while the old in the tooth 24-105, well, let\'s just say that it\'s never been one of my faves.
I wonder it focusing half way between the center and the edge might have improved the overall performance of some of the lenses that were really soft on the edges.
Interesting test nevertheless.
I did a check of both field curvature and focus shift on the Canon 24-70 f/4 IS, 24-105 f/4 IS, and Tamron 24-70 VC for all previously tested focal lengths. I tested by performing 3 exposures at f/8 using three focus methods: 1) Focus at center wide-open, 2) Focus at center stopped-down, and 3) Focus at edge stopped down. All focus performed manually using 16x LV magnification and a Zacuto magnifying LCD loupe.
