KH19x6.7-II KAS

Broadcast Lenses


In 2006 Canon is introducing a new family of portable HDTV lenses for EFP, ENG, and a range of corporate and business industrial applications. In so doing, an important hierarchy in HD optics is being created. It is important because of the highly innovative developments by the world’s major professional video manufacturers in their recent introduction of a diverse range of new low-cost tapeless HD camcorders and tape-based HDV professional camcorders. Various design strategies have been adopted by the manufacturers to decisively drive down the costs of these HD acquisition systems. They include different image format sizes, subsampled imagers, and contemporary digital recording techniques. In support of these products Canon is designing an entire new family of cost-effective HD lenses that seek to match both the performance and the costs of these diverse and still-emerging HD acquisition systems. To distinguish this level of lens within the overall Canon HD optical hierarchy they are being identified by the logo HDgc – to clearly differentiate them from the already established high performance HDxs line of 2/3-inch portable lenses.

These new acquisition systems have been developed 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 new HDgc family will include 2/3-inch, 1/2-inch, and 1/3-inch lenses.

There are two tiers within the HDgc family – one, that encompasses all of the established operational innovations (enhanced digital drive unit for zoom, focus, iris, and a 2x range extender), and a second that facilitates an even lower overall lens cost by excluding the extender system and replacing the e-Drive system with Canon’s more cost-effective new ergonomic Shuttle Shot drive unit. This KH19x6.7-II KAS lens is in the latter tier.

The KH19x6.7-II KAS is a portable HDTV production lens within the 1/2-inch image format sector of the HDgc family. This particular lens is intended for all who have as their foremost priority the use of a very cost-effective and lightweight (2.8lbs for this lens) HD acquisition system for shooting over long distances combined with reasonably wide angle capture. It was specifically designed for the HDC-X300/X310 compact HD camera and the HD XDCAM camcorders of Sony, which utilize three 1/2-inch 1440-element CCD imagers. The lens has a special feature in having an interface to the Sony-developed Auto-Focus system built into these acquisition systems. This lens is an important member of the emerging HDgc family in terms of facilitating HD imaging for point of view and other special HD applications.

The KH19x6.7-II KAS used contemporary optical design criteria to achieve an excellent multipurpose HD lens offering focal lengths up to 127mm and a wide-angle of 55 degrees horizontal. Combined with an exceptionally high sensitivity (F1.6 maximum aperture) this is a lens that can encompass an unusually broad range of shooting situations at an attractive price point.

The KH19x6.7-II KAS utilized breakthrough technologies and powerful computer-aided design techniques to produce an HDTV lens with an excellent performance-cost optimization. It is a design directly responding to the expressed creative desires of broadcasters and HD producers for low-cost HD POV and special-application acquisition systems, while also facilitating the corporate, business and industrial sectors to painlessly transition from SD to HD.

The KH19x6.7-II KAS represents a fine compromise between the demands for mobility in a handheld HDTV camera system and the high imaging performance requirements for HDTV production. 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. Relative light distribution was optimized for the more open aperture settings 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 careful control of black reproduction – with optical and mechanical design innovations that substantially reduced flare, veiling glare, and any internal reflections. Tight control of the geometric distortion at wide-angle settings constituted another central design imperative. The lens spectral transmittance characteristic was closely coordinated with that of all of the major portable cameras to ensure adherence to the HDTV colorimetric standards and to additionally support flexible creative control of color reproduction.