Biogon T* 2,8/25 ZMnnVirtually distortion-free opticsnDramatic perspectives and a view from extraordinary image angles – SLR lenses from ZEISS open up new composition possibilities. Distortion would disrupt the composition because straight lines, whose image does not go through the image center, would be reproduced with a curved shape. This annoying effect is accordingly and largely compensated through elaborate optical designs at all focal lengths.nnMinimized Focus ShiftnZEISS T*® ZM-mount lenses are specifically designed to minimize focus shift with aperture changes – an important innovation with big benefits for rangefinder photography. As a result, you can expect improved accuracy of the rangefinder-defined focus. While the precise 10-blade aperture with 1/3 stop interval click stops ensures exact exposure.nnSmooth, precise focusingnManually focusing a lens means controlling the image result from your fingertips. A good ergonomic design makes all the difference. The user-friendly focusing ring on ZEISS lenses with an ergonomic finger rest is perfect for fast, precise focusing. Changes are immediately visible in the viewfinder. The high-quality focusing mechanism moves smoothly without play, thus also supporting the intuitive interaction with the focal plane.nnZEISS T* anti-reflective coatingnAll lens elements in SLR lenses from ZEISS feature the T*® anti-reflective coating and an optical design that produces brilliant pictures even in unfavorable lighting conditions. We vacuum deposit very thin, transparent coats on the surfaces of the lens elements to make them anti-reflective. Special substances, one by one, are vaporized with very high energy in a high vacuum, which are then deposited on the glass surface as a coating with precisely controlled thicknesses to achieve the desired reduction of reflections. The first coatings were applied by ZEISS back in the 1930s.nnRobust designnThe mount and control elements of all ZM lenses are made of metal and are designed for decades of intensive use. The high-quality craftsmanship of the all-metal mounts, the easy-to-grip metal focus and aperture ring and the robust front bayonet and filter threads ensure an amazing photographic experience.