The J17ex7.7B is a wide angle of view portable lens offered by Canon to support high-performance field production for analog NTSC and digital SDTV program origination. It is a key member of a family of five portable lenses that collectively offer an unusually broad range of creative options. This particular lens is intended for producers and broadcasters having as their foremost priority a generous range of focal lengths combined with a wide field of view in a lightweight mobile production lens-camera system offering exceptional SDTV performance. The J17ex7.7B utilized breakthrough technologies and powerful computer-aided design techniques to produce a wide-angle SDTV lens in a modest 3.3 lb package. It is a design directly responding to the expressed creative desires of broadcasters and producers for a truly versatile EFP acquisition system. The optional flexibility of Canon’s Crossover aspect ratio switching system makes it a superb performer for both 16:9 widescreen and standard 4:3 image formats. ABOUT THIS LENS The J17ex7.7B represents a magnificent compromise between the demands for mobility in a handheld SDTV camera system and the anticipated performance requirements for high-performance SDTV production. It offers focal lengths up to 131mm (or 262mm with extender) and a wide field of view of 63.9 degrees horizontal for the 16:9 aspect ratio. The lens has an exceptionally high sensitivity (F1.8 maximum aperture). The requisite optimization strategies to achieve this balance sought a high MTF over the entire image plane, minimization of chromatic aberrations, and maximization of image contrast. Preservation of the highest MTF at the wider angle focal lengths (where scene detail can be particularly high) was a special priority. Relative light distribution was optimized for F2.8 and above and this uniformity of brightness across the image plane combines with the high contrast and excellent picture sharpness to produce vividly clear HD pictures. Contrast was extended by superb control of black reproduction – with optical and mechanical design innovations that substantially reduced flare, veiling glare, and any internal reflections. Similar attention to minimization of ghost images and other highlight-related chromatic distortions caused by strong light sources on-axis and off-axis further extend the operational contrast range of the lens. Tight control of the critically important geometric distortion at wide-angle settings constituted another central design imperative.