I bought this lens to go with a new Nikon D800 DSLR. Because the D800 has a full frame 36 megapixel processor, it requires excellent lenses to get the most out of it. The Zeiss ZF2 25mm f/2 is a great wide angle lens for this camera. The D800 has no crop factor, so this lens functions as a true 25mm wide angle when mounted on it, and it's a CPU lens for the Nikon, meaning you get all metering functions.
What I really wanted was to get the feel of my old Leica reflex lenses, but with the technology of a digital SLR. The build quality of this lens is second to none, the focusing "throw" is smooth like butter, and the optics are world class. Even the lens shade is made of metal! It was like using my Leica and Hasselblad lens from years ago, but with digital capture.
I bought the lens and took it out to the Monterey Peninsula in California, taking it on several trips down Highway 1 to Big Sur and Point Lobos State Reserve. This lens is superb! It is perfect for harnessing the raw power of the Nikon D800, with resolution and color rendition like you never saw before. I shot forestscapes at Point Lobos with it on a tripod-mounted Nikon, using a cable release --- results were absolutely stunning, with sharpness that is rare these days. I shot seascapes with it, I shot tight compositions with it, I really put it through its paces.
It is expensive, yes, but just get the thing and use it as your all-purpose wide angle. As far as I'm concerned, it's the best wide angle I have ever used. I have a Leica 24mm f/2.8 that cost me $1100 (used!) some years ago, but I believe this Zeiss is much better.
Just swallow hard and buy it! You will never need another wide angle lens again, this will be the one you use. The better that digital sensors become, the better this lens will get. You can pass this lens on to your children, it will never get obsolete.
The Zeiss ZF.2 25mm f2 is a new and greatly improved version of the previous Zeiss 25mm f2. Despite the design overhaul, the lens still maintains it's Distagon roots. The most obvious change is the increase in maximum aperture. This opens the 25mm focal length for low-light shooters. But delve a little deeper, and there are several other key changes. Through the addition of two aspheric lens surfaces, the field curvature that was so noticeable on the previous version has been eliminated. This also makes chromatic aberrations virtually non-existant. Using a floating element design, distortion is no longer a concern. This makes the ZF.2 25mm f2 ideal for architectural photography, as well as any other application where distortion-free images are a must. Like all other Zeiss SLR lenses, the ZF.2 25mm f2 has the Carl Zeiss T* anti-reflective coating, which enables high-contrast images and wonderful color saturation. One key difference that should be pointed out is the new Zeiss 25mm f2 doesn't focus as close as the the previous f2.8 version. This makes the focus throw of the new f2 version seem shorter. However, if you take into consideration the difference in focus distance, the effective throw is the same. The barrel of the lens is larger, so the focus ring diameter is also. For video shooters, this will be a welcome change. Like all other ZF.2 lenses, you have full aperture control from the camera, as well as the manual aperture ring for use with older Nikon SLRs and other mounts via adapters.
Roger's Take Roger Cicala President of LensRentals.com It's really, really good. That should about cover it. Oh, you want details? OK. It's an interesting lens. Unlike previous versions in this focal range there is very little field curvature (unlike the 25mm f/2.8). In terms of pure resolution it's superb, generating numbers in our testing similar to the legendary 21mm f/2.8. Sharper than the Nikon or Canon 24mm f/1.4 lenses when shot at f/2.0. Sharper than any 35mm, 50mm, or 85mm lens we stock at f/2.0. And that's both in the center and overall (weighted average) sharpness. But there's a bit of a catch: that's for testing at middle distances (10 to 25 feet). But at infinity (where the MTF charts are made) it doesn't seem quite as good (it's still good, but not amazingly good), so there are probably better choices for landscape work. But 25mm isn't really a landscape focal length for most people, it's more for reportage, street shooting, architecture, and video work. For these purposes, at middle distances, I'm not sure there's a better lens available.
Honestly I was quite disappointed in this lens as it over focused at infinity, meaning to get the crispest images on my D800e you had to back it off fractionally from infinity, and in my tests I found it to have almost no depth of focus or field, even using it f8 which is where DXO Mark say is it's prime appurure for edge to edge sharpness. It was almost impossible to get sharpest focus unless locking it down on a tripod and making several exposures with micro adjustments. When sharp the images are blindingly good, but the lens is just too awkward and unforgiving to want to use as an everyday walk around prime.