The KJ17ex7.7B is the first of a new family of second generation 2/3-inch HDgc portable HD lenses. The new design reflects design refinements to the first generation line of HDgc lenses originally introduced in 2006.
The HDgc line of lenses had been specifically developed to achieve a price performance ratio that was commensurate with the new line of cost-effective HD camcorders being introduced by all major camera manufacturers in response to the broadcast industry’s rapidly growing interest in transitioning to HDTV newsgathering, HD reality shows, and other lower-budget HD productions. They also directly address the increasing adoption of HD digital origination by the growing independent filmmaking market sector. In addition, they are anticipated to foster growing interest in HD within the broad B2B market sectors. To support this extensive flexibility in HD acquisition systems, the HDgc family includes 2/3-inch, 1/2-inch, and 1/3-inch lenses.
The KJ17ex7.7B is a portable HDTV production lens within the 2/3-inch image format sector of the new HDgc family. This particular lens is intended for users whose foremost priority is an affordable HD lens that delivers a generous range of focal lengths combined with a wide field of view in a lightweight mobile package. It was specifically designed for the many new cost-effective but remarkably high-performance 2/3-inch acquisition systems that appeared in 2008-2009.
In the KJ17ex7.7B lens imaging performance has been significantly advanced by mobilizing the most contemporary of optical glasses, optical coating materials and processes, and powerful new optical design tools. Customer feedback also spurred a total redesign of the digital drive unit that further optimized both the ergonomic aspects and the performance of the digital electronic control of zoom, iris, and focus.
The short 7.7 mm focal length translates to a 63.9 degree horizontal angle of view for the 16:9 HD image format. Combined with a focal range that has been extended to now cover a range from 7.7mm to 131mm (and 262mm with extender) this lens offers unsurpassed operational capabilities in a compact package weighing less than 3.5lbs. Focus breathing has also been significantly reduced over the predecessor lens.
ABOUT THIS LENS
The KJ17ex7.7B represents a new degree of optimization in meeting the demands for mobility in a handheld HDTV camera system and achieving the imaging quality sought in HDTV broadcast news acquisition while also essentially maintaining the price level of the original HDgc. The maximum relative aperture is F1.9 which, combined with the typically F-10/11 sensitivity specifications of the contemporary HD ENG cameras, ensures excellent video pictures in very low light environments. The image performance strategies of this new lens sought a tighter control of MTF across the entire image plane and with operational variations of zoom, iris, and focus. Minimization of monochromatic and chromatic aberrations and further maximization of image contrast combine with the improved MTF to produce superb picture sharpness.
Relative light distribution over the mid to long focal lengths is better controlled and this better uniformity of brightness across the image plane combines with the higher contrast and higher MTF to produce sharp clear HD pictures. Contrast was enhanced by excellent control of black reproduction using new multilayer anti-reflective optical coatings and new optomechanical design innovations that significantly reduced flare, veiling glare, and any internal reflections.
The lens spectral transmittance characteristic was closely coordinated with that of all of the major portable HD cameras to ensure adherence to the international HDTV colorimetric standard.