I have yet to swap out my EFS 10-22mm as a UWA solution for my kit since buying the 5D3 last spring, since I do not shoot a lot of UWA. However, this summer we have scheduled a trip to Glacier National Park, so I anticipate taking a few ultra wide shots.
My current plan is to take the 5D3, 7D, 24-105L, 100-400L, and an UWA lens. The 100-400L will stay mounted on the 7D as we travel and hike, ready for any wildlife we may encounter. The 5D3 w/ 24-105L will be my main landscape body, and used for general "walk around" shots.
For the ultra wide shots, will the 5D3 + 17-40L provide a substantial image quality improvement over just using my existing 7D + EFS 10-22? I do enlarge some special shots from our travels to as large as 24x36, so there is the potential for a UWA shot to be displayed in such a manner.
Also, would the 17-40L, when used in the 24mm range, be an improvement over the 24-105L, which suffers from distortion, vignetting and sometimes CA at its wide end? I can correct these flaws in Lightroom, but it would be an added benefit to justify getting the 17-40L.
With the Amazon credits and gift cards I've accumulated and what I could sell the 10-22mm for, the swap of lenses wouldn't cost me anything. Of course, I could always use those Amazon credits for something else if the improvement in image quality will not be worth the exchange.





