Canon KH21EX5.7 manual Concept of HDgc Series, Optical Performance of HDgc Series, Main Features

KH21ex5.7 IRSE

Canon’s Philosophy:

Canon has always developed new technology with four basic philosophies, "High Quality of Picture", "Ease of Operation", "High Specification" and "Minimize Environmental Impact". Canon's HDTV lenses are, so to speak, a compilation of our basic philosophies. Now, Canon adds a new concept to the HDTV lenses by launching the new HDgc Series.

Canon’s New HDgc Series

Concept of HDgc Series

Corresponding to the popularity of digital High Definition broadcasting and diversity of HDTV equipment, Canon has added a new series to its HDTV lens line up, the HDgc series. The new HDgc series supports the emergence of an important new generation of cost-effective HD acquisition systems. Adopting the advantages created by Canon’s unique technology, the new HDgc lenses exhibit high MTF, high resolution and high contrast from the center of the image to its extreme edges, meanwhile maintaining its compact size and weight.

Another important policy of Canon’s is not to pollute the earth and the HDgc series succeeded in excluding harmful substances such as cadmium, PBBS, PBDPE or mercury from the mechanical parts, and at the same time incorporating lead free glass and reducing the amount of hazardous substances used in electrical parts.

Meet Canon’s new HDgc series lenses, a compilation of Canon’s advanced technologies.

Optical Performance of HDgc Series

Aberration Correction for HDgc Lenses

In the HDTV system the pixel size is about half. Therefore, the spread of a point image caused by a spherical aberration, coma etc. should be diminished to about half. The MTF varies as the focus changes and even if the image is slightly out of focus, the MTF is greatly influenced as shown in Graph 1. HDgc greatly contributes to correcting and minimizing these aberrations at the same time maintaining high MTF throughout the edge of the picture.

Special Optical Elements

With the goal of minimizing chromatic aberration, the HDgc series lenses utilizes special elements including an artificially re-crystalized element, “Fluorite”, with extraordinary dispersion characteristics and the newly developed “Hi-UD” (high index ultra low dispersion) glass. Canon has succeeded in the practical use of special elements along with advanced design techniques like “separate achromatism”.

MTF(%)

100

90

80

70

60

50

40

30

20

10

0 0.02

NTSC 400TVL(30lp/mm) HDTV 600TVL(55lp/mm) F1.6

0.01	0	0.01	0.02
Defocus(mm)

＜Graph 1＞

Hi-UD Glass

Enhanced Digital Drive

The KH21ex5.7 and the KH10ex3.6 carries Canon’s original Enhanced Digital Drive, a drive unit equipped with an information display and a digital function selector so that the user can customize the enhanced digital functions much more easily and precisely. The new design enables the user to fully bring out the digital functions.

Main Features (Display Image)

Shuttle Shot : By memorizing any two focal lengths, the digital drive can automatically "shuttle" between the two points, moving in either direction.

Framing Preset : An angle of view can be preset in either of two memories and the lens will zoom to that position by pushing a simple button. During a performance, framing preset will reproduce the zoom position decided upon at the rehearsal. It is easy to repeat the same zoom as often as you like at the highest speed or in a preset zoom speed.

Speed Preset : A specific zoom speed can be preset in memory and it is possible to repeat the zoom speed as

often as you like by pushing a simple button.