Image sharpness on 17-40 F/4 L lens

[Daniel Browning]

I took a few shots of my backgarden at f/16, and zoomed in 100% (!). You could say I'm picky (I am!), but I wasn't entirely satisfied with the results.

At f/16 the softness of the results were entirely due to diffraction. My comments were with regard to the performance at f/4.

The lens seems to be at it's worst at the wide end.

Agreed.