Canon 10-22 with 7D or 17-40 with 5D3

[davidgator]

I own a 7D and 10-22.  I just purchased a 5D3.  Is IQ better with the 17-40 on the 5D3 than the 10-22 on the 7D?  I'm trying to decide if i should sell the 10-22 and buy the 17-40.  I do not do video so this is just for landscape photography.  Thanks for your input.

[Mt Spokane Photography]

I could never warm up to the 17-40mm on FF, and the 10-22 is wider on crop than the 17-40mm is on a crop.
It wasn't bad, but not magical either.  Since I've only had the one copy, it could have been a copy that was not as good as it could be, but others often report the same thing.
 
Here is a image from Yellowstone with the 17-40mm L and my 5D Mark II.  Its f/16, so maybe some diffraction effects.
 

[neuroanatomist]

If you stop down to f/8-11, they'll be pretty similar in IQ, but the 17-40 will have more distortion.

[IIIHobbs]

Depending on which end of the 10-22 you use most, I suggest either the 24L or 35L for the 5DIII. Or, the TS17 or TS24 if Landscape is your aim.

Keep the 7D and the 10-22 together. You can use any of the other lenses you buy and still keep your ultra wide setup intact.

[michi]

Honestly, I don't think you'll see much difference.  The 17-40 I had wasn't anything to brag about.  If you have a 5DIII, I would certainly pair it with some top notch glass.  Keep your 7D combo for now and save money for something better.