Canon 14mm F2.8 vs. NEX 16mm F2.8 w/wide converter: is it worth it?

[Piotr Wozniacki]

As can be read in my signature, I use vintage FD glass on both the FS100 and Letus adapter with EX1 when I need that shallow DOF look in my 2-camera shots. The widest Canon prime I have is currently 24mm F2.0, and - while plenty wide on the Letus - it's not wide enough with the S35 sensor of my FS100...

I do have the NEX 16mm/F2.8 with wide converter, but as we know they are not brilliant as far as sharpness is considered (though not that bad, either). I'vee been thinking to buy the widest FD ever made - the 14mm F2.8 - but it's difficult to spot, and while the more popular FD glass comes really cheap now - this one can be quite expensive

Please advise: does the Canon 14mm F2.8 provide enough advantages IQ-wise over the NEX 16mm F2.8 (w or w/o wide converter) to justify the expenditure?

TIA

[Alister Chapman]

I really like the Samyang/Rokinon 14mm f2.8. Great, super sharp lens for very little money. Proper manual iris ring too. There's even a cine version with 0.8 gears for focus and iris. It's better than the Sony 16mm. Comes in Canon EF and Nikon mounts.

[Piotr Wozniacki]

Thanks Alister for chiming in; as I'm still using my Letus Elite 35mm adapter (with EX1), I'm after an ultra-wide lens that could be used with both that, and the FS100.

I don't like too many standards and adapters, so I'd buy this lens without hesitation if I found it in FD mount...

[Piotr Wozniacki]

I bought an FD-mount Tokina 17mm F3.5 off eBay, and am very disappointed with how soft it is when fully opened at F3.5:

http://www.moldcad.neostrada.pl/pictures/grab.png

Could anyone tell me whether this was normal for such a wide lens, back when Canon FD was a current standard? The seller is a very nice guy and he offers refund; should I return it or keep it and sharpen in post?

PS. My other FD glass is tad sharp!