Hard to believe that ZEISS has authorized this lens.

edit: have my subsequent product evaluation depreciated retrospectively on 1 star: See my answer to a well-meaning contribution to the discussion and after I disappointment despite the objective here again, this time NEW've bought:

Original Review:

I bought from Amazon Warehouse Deals this glass.

The lens will cost indeed used only slightly below original price.
which can actually close to good and desirable commodity, when you can not go wrong.

Short: The lens has me compared to "standard-almost-free-kit-zoom!" (SEL 1855 OSS) very disappointed.

The mechanical quality of the lens is very good - but not great !, overlooking the rich price.
The rather cheap-looking plastic inner tube with slight play in telephoto position and the plastic lens hood, whose snap from experience soon likely to wear out ruin something the positive overall impression. Otherwise, there's nothing to complain about. From the dimensions of the lens will fit perfectly for the NEX-6, Nex-7 or A6000 and evaluates them on enormous without it acting pretentious or unbalanced.

Visually, however, me the Zeiss 1670 unconvinced. And I have placed less emphasis on distortion and vignetting.
Especially since you can use both characteristics also creatively.
Clearly as I see quality criteria but sharpness and chromatic aberration.

And here the SEL 16-70Z F4 OSS missing
The glass forms not overly keen on, not even in the center, it may be at that point of my standard zoom SEL 1855 not really settle for a fraction of the price.
It also shows significant shifts in chromatic contrast-strong edges that are already clearly perceives when magnified on the camera monitor.
That did not even bring the kit lens.

Since it could not appease me that the Zeiss offers a slightly better color brilliance.

Resumé
The lens is not really bad, the focal range and the continuous initial aperture, the dimensions and the mechanical quality make it very attractive,
But with the really important points to even digest the price, because the glass can not deliver!
The aspect that clearly visible dust inclusions were at delivery already visible behind the front lens, then hardly played a role.
I've never been convinced so quickly away, as in this case, that this purchase, must be returned to well above 700.
It surprises me that this product Zeiss gives his name and such average lens is asking apparently.

No - I do not like! 2 stars