They have the 14mm F2.8 Samyang beating the 14mm canon in most everything except distortion. $400. Mine just arrived today and so far I wouldn't expect a whole lot more from the corners of such a lens. The 24 F2.8 II canon I just got is also good towards the corners full frame.
http://www.photozone.de/canon_eos_ff/532-samyang14f28eosff?start=2 Just look at the samples on there. Kinda crazy resolution. Maybe 14mm is too wide for what you want?
Considering the 14mm F2.8 Samyang myself as the 14L II is out of my budget for such a specialty lens. Am a little worried about possible QC issues with the Samyang though, it really is that cheap!
14mm is in! A few quick shots and I'm impressed with the whole package for only 320 euro's
Cool. Mine is pretty impressive so far as well. One thing I've noted is according to lenstip the canon only beat it in distortion, build and having autofocus. Pretty fast I'm noticing their vignetting results having it better than the Canon just isn't true. So Canon wins that one too. I'm not sure how useful it will be at F2.8. But anyway, lenstip has it -2.58 EV full open fall off, while they have the canon -3.00. I used the Canon earlier this year and it was clear pretty fast with this Samyang it's vignetting wide open was even more severe. Photozone has this the right way and backward from what lenstip says.
I also just bought a 50mm F1.4 and noticed in looking at the options lenstip had the sigma and even the 1.4 zeiss smoking the canon wide open and stopped down. Like the canon looked like ass. I look at photozone and the opposite again. Picked up the canon 50 1.4 yesterday and it is great. I guess I'm not so excited for lenstip reviews at this point. Or perhaps it's just reviews in general are in a way kinda pointless given how so many don't at all match up with others. Like you have to find 4 or 5 and pick the winners that way. Or just buy the dang things.
Figured since I'd been praising the samyang over the canon so much that I'd mention this anyway. You stop that thing to F4 and still a lot of vignetting but by F5.6 it's a non-issue and gone by F8. I'm amazed it is so sharp even wide open though, corner to corner full frame. Also the flare deal is a nice thing to see as well. I can point it at the sun with no worry. There's only one small angle to hold it with the sun way in the corner to get that flare to shoot across. It's such a tiny range it's not an issue.