zeiss 18mm vs 17-40 on 1dmkIII

Wide angle for my 1d3!

Landscape photography first of all!

i already have the superb 35L and this will be my only wide angle lens . . . the quality of the zeiss worth it?

The 21ZE is a better performer if you are willing to forgo few millimeters.

I never used the 18 on anything but a 5d however it was a better performer than the zoom, you cant beat the versatility of the zoom though, an since you are comparing the two, you dont seem to mind the slow f stop, ( guessing for landscape) id probably go for zoom as neither lens will show its flaws as much on a 1.3 sensor.

the distagon 21ZE is out of budget, at the moment . . .

the most important differences between the 18/3.5 and the canon zoom are:

1- manual focus vs auto focus (this is not a problem for a wide angle lens, especially for landscape pourpose. . . )

2- versatility of a zoom vs fixed focal lens

3- overall quality (resolution at TA and stop dowun, flare, contrast, colors, distorsions, build quality) zoom vs zeiss???

Obviously the canon zoom wins in terms of versatility, and i think that zeiss outperform the 17-40 in terms of "overall quality"

i use, till now, just a 35L (that is a 46mm on apsh) and a canon 70-200 2.8 . . . is really more comfortable to add a 17-40, or a zeiss 18mm cuold be perfect???

It boils down to a personal choice in the end.
I would favour the 17-40 it does more.

According to this chart the Canon 17-40 is sharper then the Zeiss 18 at f/8. I know the corners are more distorted, but it is sharper. I know I'm trading my 17-40 for a Zeiss 21 soon. http://www.the-digital-picture.com …omp=0&FLIComp=0​&APIComp=3

Take Care,
Cheers, Patrick