TokinaFRN-MF20FXSE 20mm f/2 FE MF Lens for Sony E

Couldn't get the left side of the frame in focus at the same time as the center and the right side. Bad quality control. Returning this copy but will go for a different WA lens in the end because it felt to me like wide open it had pretty low contrast where it was sharp, and the colors weren't very punchy.

This new lens by Tokina is a very nicely made. It is all metal with brushed finish and is a pleasure to handle and operate. The hood is the only plastic part, which is perfectly fine in my opinion.I've encountered three following problems, which eventually resulted in my returning this lens for credit.1. The lens I received had a fairly strong de-centering defect, necessitating stopping the lens down to F5.6 in order to obtain acceptable corner-to-corner sharpness. Until F5.6 the lens was unusable, since one side of the frame was always out of focus. Strictly speaking, this defect has little to do with actual optical de-centering and is a result of poor quality control and sloppy assembly. I am sure, I could have corrected it by shimming the lens mount as needed - but for $799.00 lens made in Japan I simply expected to get a working lens out of the box. For classical landscape photography, where one would stop the lens down F8.0 - F11.0 to achieve maximum depth-of-field without causing too much of image quality deterioration due to diffraction, this de-centering may not have mattered that much. However, I intended to use the lens for astro-photography, where critical sharpness at the widest aperture setting is required. The lens I received had failed to deliver in this regard.2. The lens, despite being the native Sony FE mount, does not provide fixed infinity focus setting, making it even more difficult to use for astro-photography. The reasons for Tokina deciding not to employ the fixed infinity focus setting in this manual focus native mount ultra-wide angle lens are a mystery to me, but perhaps they are valid somehow.3. Finally, even with the limited electronic interaction with the camera this manual focus lens provides, I've experienced electronic issues, where for no reason a distance scale would pop up in my viewfinder. I was going to ignore it, but the problem intensified and finally I began experiencing intermittent jams with my A7RII camera, where camera would simply turn off and required removal of the lens and removal / reinsertion of the battery for a restart. This, of course, was not acceptable behavior either and a return was definitely indicated.Otherwise, the lens is well made and feels great on Sony A7RII. Even this flawed copy was very sharp between F5.6 and F11.0. I especially liked the contrast of this lens, which is somewhat pleasantly lower by comparison to the current generation of optics, resulting in a better detail in the images. It is fairly easy to raise the contrast fi you so desire, either in camera or in post-processing. The color balance, while leaning slightly to yellow-green, was also very pleasant and again this can be easily controlled as needed. Had it not been for the problems i've encountered, i would have probably happily kept the lens.I am hoping that Tokina will correct the noted problems in the next batch. Until then, I can not recommend this lens.

If you've read any of the reviews then you know this lens is highly regarded. The MTF chart is impressive and so is the price, and I was in the market for an astro lens so this seemed like the perfect deal. Now I've found that you'll only be satisfied if you get a good copy. I tested my copies against a resolution chart as well as using it at infinity focus.On the 1st copy I received the corners were an absolute mess. Not one, but all 4. I've never received a lens like this before so I figured it must be a defective copy. I sent it back for a replacement. To be clear, the corners on this initial copy suffered from extreme field curvature and didn't sharpen up until f/11 if you focused on the center. To get sharp corners at faster apertures I had to focus very close to the edge of the frame, but then the center suffered noticably.My 2nd copy was better but still had some issues. Only 1 corner was good from wide open. 1 corner was decent but acceptable. 2 corners were unacceptable with one being exceptionally bad and didn't sharpen up until f/11. Once again, this was using the center as a focus point. To get that one corner sharp at faster apertures meant sacrificing resolution across the rest of the frame. I briefly thought about keeping this copy but I ended up returning it. I don't expect perfect performance across the frame but I do expect any defects in sharpness variance to be acceptable.I may have gotten unlucky with my copies, the lens does get some high praise after all. However it's worth pointing out that other people have had similar experiences with this lens, including Phillip Reeve who runs a popular lens review website.Other than those hiccups, the lens performed very well. When the lens is sharp it's a razor. Build quality is nice as is the handling. Flare resistance could have been better but it's actually pretty good compared to Tokina's other lenses. I don't like the square hood, that would be my only complaint aside from the QC with the optics.