Upload & Sell: On
So, I haven't really had a chance to shoot more than a few quick test shots outside my work building, but here are my first impressions on the Touit 12mm:
Size/Build: It's very similar in length to the Fuji 14/2.8, but the Touit is significantly larger in diameter, and the hood makes it larger still. While overall volume isn't drastically different, it FEELS enormous in comparison, and it doesn't fit in my bag nearly as easily.
The build quality is excellent. It's a plastic lens, but it's extremely solid, and very tightly put together....feels good in the hand. I'm not a huge fan of the smooth rubber rings, but that's personal preference. AF is fine for an ultra-wide, but it's certainly not fast...it's about half the speed of the Fuji 14, but it's plenty fast enough for any major use you'd have.
Image quality - this will be continually updating. First blush, it looks to be quite a good lens. It's sharp to the corners (though not blisteringly sharp), and has a very neutral color rendition. In comparison, the Fuji 14 is sharper than the Touit 12 across the frame, at least on the first lone test I did.
I don't want to show the full building where I work, but what I did is go out, frame a shot of the front of the building with the Zeiss 12mm, then swap to the Fuji 14mm, and back up about 2 steps to keep the exact same framing, so you should be able to get a good idea of resolution and contrast between them on the same size subject. Of course, the 12mm is wider, so if you need the extra 2mm, it may be irrelevant how it compares to the 14mm.
100% crops, straight from LR 5 (on my 1080p screen, I need to hit the magnifying glass to see 100%):
Here you can see that while the Touit 12 is fine, and quite even in resolution across the frame, compared to the Fuji 14, it trails both in the center and in the corner, across the aperture range (f/5.6 was similar). I included the crop off center at f/8 to really show how the 14mm shows up on resolution (though there's some difference in background compression here due to the longer focal length).
However, if you're not doing head to head, the Zeiss 12, so far, looks to be a pretty good lens. Perhaps not exceptional, but pretty good. It doesn't have any real weakness at the edge of the frame, and it's a nice wide angle.
I'll update here as I shoot a lot more with the 12mm as the week goes by (I'll also do a better comparison than just this one quick one.)