RS's reviews

Carl Zeiss 135mm f/2 Apo Sonnar T* 2/135

I rented this lens and the Nikon 135DC f/2 at the same time and used them for a portrait gig on a D800E on a tripod with remote shutter release.

The two lenses performed almost identically, I can't really tell them apart from normal viewing distance. But the lens is fun to use—it's a joy to turn the focus ring and watch the subject snap into focus.

The main difference is that the Nikon lens had that Nikon purple and green fringing at the edges of everything and the rendering was not quite as crisp as the Zeiss. But crispness is not usually a good thing with portraits—it draws attention to every hair, zit, and mascara crumb. So beware if you're going to use this lens for portraits.
I would try a Softar or a one of the lighter grades of a Tiffen Black Pro-Mist on this lens next time I shot a woman with it. Or just get the 135DC, the photos it produces are very flattering.

The question that this lens answers is "Will zeiss lenses give me medium-format quality images from a D800?" And the answer, at least for me, is yes.