Carl Zeiss Jena Visionar 92mm f1.6 - Photo Set

My Cuban friend Ramon generously gave me two of this prized Carl Zeiss Jena Projection lenses. The 92mm f1.6 is one of them. These are absolutely gorgeous lenses, both in built quality and optically. I believe these lenses are uncompromised design using the then latest techniques and material. The large aperture and size of the lens would make these lenses extremely expensive to make. Perhaps, these lenses were made for theater projections, but that's just my guess. In any case, they are beautiful lenses no matter how you look at them, and they produce very pleasing pictures.

Little House in the Forest - NEX-6 & Carl Zeiss Jena Visionar 92mm f1.6. Click for larger.

Mismatched - NEX-6 & Carl Zeiss Jena Visionar 92mm f1.6. Click for larger.

Rust - NEX-6 & Carl Zeiss Jena Visionar 92mm f1.6. Click for larger.

Maple Flower/Seeds - NEX-6 & Carl Zeiss Jena Visionar 92mm f1.6. Click for larger.

Daisies - NEX-6 & Carl Zeiss Jena Visionar 92mm f1.6.

Carl Zeiss Jena Visionar 92mm f1.6 Projection Lens

This lens, and the Visionar 109mm f1.6, are special. They came all the way from Cuba and was a gift from friend Ramon. These two lenses are very large and heavy, especially the 109mm f1.6, mostly due to the very large maximum aperture of f1.6. After so many years, they are still in pristine condition. I was able to quickly mount the lens to my Yeenon focus helicoid and they fit well together.

Visionar 92mm f1.6 on NEX-6. Note the large size, and how clean it is. Click for larger.

On Monday I shot some pictures in the afternoon, but it was sunny and very bright, and the lens has a fixed aperture of f1.6, thus most of the pictures were over exposed. No, I didn't have any ND filters. Yesterday, it rained, and was dark, perfect condition to use this lens. So I spent an hour in the rain, under the umbrella, and enjoyed myself with this beautiful lens.

Like most projection lenses, this one is very sharp at the working aperture of f1.6. Unfortunately, quite strong color fringing/CA is visible with contrasty/back lit scenes, as most projection lens exhibit this trait. Not as bad as others, though. So far, I haven't found any projection lens that produces very pleasing  bokeh. It was simply not a design criteria for a projection lens. This one, I would say is average. Not ugly or unpleasant, but not as nice as many dedicated picture taking lenses.

The hardest part of using this lens is finding critical focus. The extremely thin depth of field makes focusing really difficult. Nonetheless, I had a great time taking pictures with this wonderful optic.

Daffodil  - NEX-6 & Carl Zeiss Jena Visionar 92mm f1.6. Click for larger.

Bokeh - NEX-6 & Carl Zeiss Jena Visionar 92mm f1.6. Click for larger.

Braving the rain - NEX-6 & Carl Zeiss Jena Visionar 92mm f1.6. Click for larger.

Walking in the rain - NEX-6 & Carl Zeiss Jena Visionar 92mm f1.6. 

Speed Booster Alternative

Picture comes from here. Click for a larger version.

You can always count on the Chinese to come up with something cheaper, though not always better. When the Metabones Speed Booster came out, I wondered why no one else had done it before. Surely, the design  is not something new. Focal reducer has been around for decades. But I knew as soon as the Speed Booster come on the market, the Chinese version won't be far behind, and now there is the Lens Turbo, an alternative to the Speed Booster.

Specs for the Lens Turbo:
Multiplier: 0.726
Optical Construction: 4 elements in 4 groups with 1 ED element.
Note: Not compatible with all lenses. The Lens Turbo adapter is thinner than a normal adapter. Some lenses  with rear element protrudes more into the mirror chamber may not fit, and the aperture lever for the MD version may hit inside of the adapter, preventing the lens from mounting properly.

According to Dr. Liu, designer of Lens Turbo, its design is different than the Speed Booster. He said that Speed Booster concentrates the light more in the middle of the frame, and his design distributes light more evenly across. From early sample pictures, the speed gain seems dependent on focal length; the gain is less than a full stop in some cases. Some softness wide open. It's pretty safe to say that Lens Turbo is not as good optically as the Speed Booster, which is understandable. The difference in price is more than double. Also, Lens Turbo does not have any kind of electronic contacts; it can not control the aperture of EF lenses.
If you are interested, here is a thread in Chinese, talks about the user experience with the Pentax version of the Lens Turbo. If you don't read Chinese, you will need to translate it. Another thread by the designer of the adapter is here, also in Chinese.

I think this is a good start for the Chinese adapter. Competition is good for consumers. Hopefully both the Lens Turbo and Speed Booster will improve, and lower prices soon. Better yet, I hope there will be more high quality focal length reducers to come on the market.

EcoCabs - NEX-6 & Carl Zeiss Jena Visionar 92mm f1.6 Projection Lens. Click for larger.