The Giant Hasselblad lens – Zeiss Apo Sonnar T* 1700 mm F4 lens No this is no joke, this is a real ‘monster lens’, that was specially made for wildlife photography? The ZEISS Apo Sonnar T* 4/1700 was developed by Carl Zeiss for a customer with very particular and high demands, with a special interest in long distance wildlife photography. To achieve the highest possible image quality, the customer decided on the Hasselblad 203FE 6x6cm medium format camera and a ZEISS Lens as the best combination for his special needs. This monster lens weighs in at 256 KG (564 lb) and uses unique methods for handling focusing (because of the weight of each glass element). This lens becomes the largest telephoto lens for non-military use anywhere in the world. The price wasn’t disclosed nor was the private owner, although some of the text on the lens is in Arabic and it carries a ‘State of Qatar’ emblem, which gives us slight clues. At a focal length of 1700mm and a speed of f/4, this project even challenged the manufacture of the optical glass. The delicate, special glass types required for this unique design had never been cast before in such huge dimensions. Some of the resulting lens blanks weighed more than 25 kg (55 lbs.) and were valued more than a luxury sedan! Turning these blanks into the finished lens elements added even more to their value. The design of the ZEISS Apo Sonnar T* 4/1700 required new lens assembly techniques and quality assurance methods never before applied in photo lens production – even by Carl Zeiss’ normally high standards. The staggering weight of this unique lens placed unique demands on the focusing mechanisms. To address this issue, Carl Zeiss developed a totally new way of operating a telephoto lens, including servo controlled aiming and focusing systems like those used in large telescopes and similar instruments for astronomical scientists. Drawing from its expertise in developing and producing satellite and space optics, as well as ultra-high resolution microlithography lenses for semiconductor fabrication, Carl Zeiss was happy to accept this challenge. The resulting Carl Zeiss Apo Sonnar T* 4/1700 lens consists of 15 optical elements in 13 groups. It is the largest telephoto lens ever produced for civilian photographic purposes and is a testament to the precision design and manufacturing capabilities at Carl Zeiss.