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It is no doubt the Zeiss Otus 55/1.4 APO Distagon is the lens of the century, at least for now. Never before, has Zeiss removes the restriction of size and other optical design cnosiderations for the design team of Otus, and deploys one ashperical lens element, 6 lens elements of special glass with anomalous partial dispersion and a complicated optical formula of 12 lens elements in 10 groups for a lens of standard focal length. The end product is a gigantic and beefy modern looking standard lens of Distagon design, a lens with an optical performance that is a class of its own, very well corrected for optically, and with a resolving power that can over match the latest 36 megapix full frame sensors!
As for price, I still believe Zeiss puts some consideration on the final cost of the lens. Although no where consider cheap, but with the type of optical performance, Zeiss still cap the price of this lens to a reasonable level (compared to Leica for example) and for obvious reason the lens is made in Japan rather than Germany to keep the price to an affordable level at least for the professionals.
As a result of the elaborate design, the distortion is kept to very low. The MTF is very impressive, supercedes all the Zeiss super stars like Makro-Planar 100/2.8, Planar 100/2, Planar 85/1.2, Planar 55/1.2 and Superachromat 300/2.8. The 40 cycles/mm line at f1.4 is already exceeding 60% almost across the field. Stopped down to f4 will further improve the performance but at f1.4 the MTF is already very impressive and setting new standards in lens design. Zeiss has been very stingy in crowning their lenses with APO designation. The previous few are Tele-ApoTessar 300/2.8, ApoSonnar 200/2, ApoSonnar 135/2, Apo-Makro-Planar 120/4 and etc. All of these APOs come with killer performance. Now the APO goes with 55mm focal length, we can expect killer performance from the latest Zeiss flagship.
The size of Otus 55/1.4 is rediculously huge, with a filter diameter of 77mm and a weight close to 1kg. It dwarfs the Rollei QBM 50/1.4 Planar(as shown in the first photo next to the Otus), which is probably the smallest 50/1.4 Zeiss has made in the history with a filter size of only 49mm. But to me despite the weight and size, the lens is very comfortable to hold and use on a SONY Alpha 7R with vertical grip. But I have to admit the lens is heavy to carry around in the camera bag, but certainly not so when in use.
The lens optical formula is a Distagon wide angle design to allow more possibilities of optical corrections as compared to the well proven and copied Planar design which more or less has reached the limit of technical possibilities. Focusing throw is very large and smooth, which allows very accurate focusing at f1.4 coupled with full frame mirrorless focusing magnifier function. For this lens Zeiss has moved away from the conventional complete lens group focusing method and using internal focusing. The focusing grip is an adequate ring somewhere in the middle of the lens, and the rest of the lens are just not moving while focusing is done.
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