Carl Zeiss Distagon T* 35 mm f/ 2.8 C/Y Lens

By far the best lens in this focal length I've ever owned. Extremely high resolution, contrast and that three-dimensional quality the best Zeiss optics exhibit. If I had to be limited to just one lens, this would be it. On the superb Sony sensor of my Sony 7R (36.4 mps) I can produce noise-free enlargements that rival medium format digital or film cameras. I shoot 6x6, 6x9 and 4"x5" (9x12) film cameras but are using them less and less. 

Weaknesses:

I have to use an adapter to mate the Distagon to the Sony E mount. Also, most adapters are shiny black anodized aluminum and strong lateral lighting caused flare until I applied matte black lacquer to all of the interior surfaces (except mount locking mechanism).

Comments:

Without a doubt, the best value for money in a professional lens. Currently running $250-300 in excellent condition from internet sources. I use the Contax No. 3 Sunshade with 67/86 adapter ring. I find the one-size-fits-all plastic tulip shades from Asia don't shield the lens enough, especially in the intense lighting in deserts and mountains here in Califonia.