The new XF 16mm f/1.4R WR (second from the right)
Update [May 15, 2015]: Due to an unexpected delay in shipment, we did not receive our stock on the 14th as hoped for. According to tracking, we should be seeing a partial shipment arrive on Tuesday, May 19th. Unfortunately, the first shipment is not quite covering our pre-orders either. Hopefully we'll see the balance in a couple of weeks...
The good news is that I have had an opportunity to thoroughly test a production sample of the lens and have posted a follow-up review and a gallery of images on my personal blog here:
-------------------------------------------------------------------------------
Like the 23mm and the 14mm f/2.8, the new 16mm seemed 100% corrected optically for distortion, therefore no software correction will be needed; straight lines render straight with no apparent barrel or pincushion distortion, even at the very edges of the frame. In addition, I could see no evidence of any chromatic aberration either. With its Nano-GI anti-reflection lens coatings (which the older prime lenses do not have), it proved extremely resistant to lens flare when shooting into the sun as well, something that fast, wide-angle primes are often not very good at. Corner sharpness on the preproduction lens was exceptional as well, and once the lens was stopped down to /2.8, the corners were already essentially as sharp as the centre. Even wide open at f/1.4, the centre of the frame is tack sharp, the edges were very good and only the extreme corners showed some obvious softness. Even the wide-open bokeh was surprisingly smooth and pleasing, not something one would necessarily expect from such a wide lens.