Carl Zeiss Distagon T* 25mm f/2.8 is a manual focus lens for Contax SLR cameras. It is not as famous as Distagon T* 21mm f/2.8 or Distagon T* 28mm f/2, nicknamed “Hollywood” (all Zeiss C/Y models). But it is a Zeiss lens and as such the build quality is simply outstanding - the barrel is all metal and both focusing and aperture rings are fully rubberised. From what I could gather image quality should be great as well, although not as good as modern Zeiss 25mm lenses for Canon and Nikon.
I have been struggling for a while to find a worthy wide-angle option for my a7R and stopped on this lens mainly due to its Distagon design, compact size and affordability - right now it sells for £300-400. I bought my copy from London Camera Exchange in mint condition for £399. I also bought the Novoflex NEX/CON adapter from SpeedGraphic, where I usualy get adapters and filters, for £99.
|Lens Construction||8 elements in 7 groups|
|Angular Field||80 degrees|
|Lens Hood||G-12 soft hood or No.1 metal hood|
|Lens Case||No.1 (included)|
The lens fits very nicely on the a7R. Well balanced, not too long and heavy. It's truly a pleasure to use. The focus ring is well dampened and smooth, aperture ring clicks nicely and securely every full-stop down to f/22. The inner cam of the lens extends slightly during focusing towards close-up. Fortunately, the front element does not rotate.
This lens has a nice colour rendering, a bit warm and dreamy. There is some chromatic aberration, distortion and vignetting that can be easily fixed in Lightroom. It is also prone to flares somewhat, probably due to its age and lack of modern coating. But flares are not very bad and can be controlled with a hood or even using a hand.
None of the issues that plague a7R with so many wide angle lenses are present. There is no magenta casts in the corners, no yellow casts at the top and bottom of the frame, there is also no smudging and loss of detail in the corners - at least no more than any wide angle lens produces even on modern DSLRs.
However, and very unfortunately, this lens on a7R does not produce sharp images across the f-stop range. With the exception of f/8 all other apertures are slightly out of focus. Maybe it is my copy of the lens, but I could clearly see the loss of detail when using Manual Focus Assist at x14. It is pretty strong at f/2.8, better at f/4 and somewhat noticeable at f/5.6 and f/11.
Here are two examples, the first was shot at f/4 indoors. You can clearly see the lack of blur in 100%crop. Shutter was 1/90 and ISO800, so definitely no reason there for the image to be blurry.
The second was shot at f/8 and you can see that both centre and corner crops are quite sharp.
Overall this is a nice lens. Not as good as modern Zeiss 25mm lenses for Canon and Nikon, such as Zeiss Distagon T* 25mm f/2 ZF2. But on the right camera you can get fantastic results. On the a7R unfortunately this is not the case and this lens disappoints, being usable only at f/8. Having said that, this lens does produce better image quality at f/8 than most Leica M and Zeiss ZM 24mm and 28mm lenses. I wouldn't get it as my only C/Y lens even for landscape, but if you own or investing in some C/Y kit than this lens can definitely work as long as you stick to f/8.
I bought this lens mostly for landscape photography, but being limited to f/8 is an issue. Especially because there are other 24mm legacy lenses out there that might not be as sexy as this Zeiss, but able to produce better quality images across wider f-stop range.