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Three New CFE Lenses from Zeiss for Hasselblad
Hasselblad has just introduced three new CFE lenses for its 6 x 6 medium format precision camera system. These are the Zeiss Makro-Planar T* 4/120 CFE, Zeiss Sonnar T* 4/180 CFE, and Zeiss Superachromat 5,6/250 CFE. These new lenses will replace the previous CFi versions and expand the range of ”electric” CFE lenses, which so far included the Planar T* 2,8/80 CFE, Distagon T* 4/40 CFE, and Tele-Superachromat T* 5,6/350 CFE. The optical formulae of the new members of the CFE range are the proven ones of the respective former CFi versions.
A CFE lens in the Hasselblad system incorporates a fully mechanical Prontor central shutter (indicated by the ”C” in the designation) with added f-stop simulator electronics and databus connectors (indicated by the ”E”), which are utilized by Hasselblad camera bodies with TTL exposure metering systems for data interchange between lens and camera body. These camera bodies include Hasselblad models 202 FA, 203 FE, and 205 FCC (hence the ”F” in the lens type name, indicating that it can be conveniently be used with focal plane shutter Hasselblad cameras). These advanced camera bodies now have far more lenses available with which the TTL capabilities of the cameras can be fully utilised.
The quick and convenient way of taking photos with TTL auto exposure can now be had with a wider variety of lenses, 9 to be precise, in the Hasselblad system. Since the 200 series Hasselblad cameras are the preferred types of highly demanding Hasselblad users, who are after the very best, Hasselblad eventually wanted to ”electrify” those high-performing lenses that are particularly interesting for customers with top expectations. One particular application will greatly benefit from the new opportunities: Close-up photography. With the new Makro-Planar T* 4/120 CFE any exposure compensation needed due to extension will be accurately detected by the camera’s TTL metering system and will automatically be taken care of.
Including the ”E” with a CFi lens is not as simple and straightforward as snapping an electronic printed circuit board (PCB) into a lens barrel and add a few gold plated contacts. The main difficulty is this: connecting the PCB, which has to be attached to the central shutter within the lens and has to travel with it during focusing, in a flexible and at the same time durable way to the non-moving gold contacts at the lens bayonet. With the three existing CFE lenses this was rather easy: The short focal lengths of the Planar 80 and Distagon 40 lenses imply relatively short displacement out to minimum focus extension. Standard ”flex bands” from the electronic industry could be used to provide the flexible connections. The flex bands hide behind other components in the lens barrel and thus do not reflect stray light.
The situation with the new lenses was more difficult. In each, the shutter can travel considerably during focusing, therefore asking for a very flexible connection. Of course, these connectors do exist. But they are designed for the requirements of the electronics industry only. Optical aspects are not considered at all. As a consequence, their reflectance for incident light is unacceptably high for straightforward use within Zeiss/Hasselblad lenses. A solution for flexible connection had to be developed by both Hasselblad and Zeiss, that performed on the electrical side to Hasselblad’s high reliability demands, and that also met all the stray light absorption needs of top notch Zeiss lenses. The new solution for a flex band had to be light absorbing to a very high degree, initially and over several decades, to comply with Hasselblad’s long service life philosophy), to endure desert heat, arctic cold, rain forest moisture, salty sea air, vibration, transport in unclimatized aircraft cargo bays during transcontinental flights, and the like. After all this has been tested and verified, Hasselblad is now confident to introduce the new devices within the new CFE lenses. | |
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