Somebloke wrote in post #16609739
I think saying the 17-40 is 'pathetic' may be a poor choice of words-a short visit to the 17-40 thread would show countless images that are quite good?
Bonbridge wrote in post #16610274
People who worry about the corners are starring at the computer the whole day to spot some faults. No, it is not the sharpest lens for the corners, but I never had to throw a picture away by it's corners. Seriously, people worry to much about such thing.
It's all relative. I used the 17-40L on a 6D for a year, as I said earlier, and during that time I got some great shots. But they'd be better if they were sharper. Personally, I don't want to settle for major compromises in IQ if I'm investing in a full-frame setup. If I subscribed to the "it's all in the photographer" philosophy, I might as well be shooting with a $400 Rebel and cheap glass.
As some of you mentioned, a lot of it comes down to the subject. There are plenty of scenes where the effect of corner/edge sharpness is masked by the subject. In those cases, especially outdoors with landscape work, the 17-40L is great. It gives such great colors and contrast, which is why I put up with it for awhile. But when there is detail anywhere near the borders, you're going to notice the softness; and in my experience, it usually didn't even require much pixel-peeping.
JM Photos wrote in post #16611962
You guys still didn't answer my other question from above. I'll paste it back again in case you missed it.
First, get the Adobe Lens Profile Downloader.
Once you have it, select the following using the top bar:
Camera Make: Canon
Lens Model: Samyang 14mm f/2.8
You should see two profiles, one for JPG and one for RAW. I've used the RAW one quite a bit for the 6D+14mm combo and it works quite well for removing the distortion. For vignetting, you'll probably have to play around with the manual correction a bit, since it varies so much by aperture (and aperture is not electronically transmitted by this lens, so the profile can't account for it).