CJ20ex7.8B IASE S Overview

Over several decades of manufacturing portable HD zoom lenses for ENG and EFP, Canon HD lenses have earned enthusiastic support from customers the world over, due to their excellent specifications, superb optical performance, and long-term reliability. Now, Canon has developed the portable CJ20ex7.8B 4K UHD lens, combining outstanding optical performance and support for 4K UHD (and HDTV) broadcast production. Featuring a focal length range of 7.8-156mm (15.6-213mm with the built-in 2x extender) and a 20x zoom ratio, the CJ20ex7.8B 4K UHD lens is able to maintain high 4K resolution and contrast from the center of the screen all the way to the edges.

The resolution around the edges has been improved by achieving advances in the inner focus system In addition to the improvements in optical performance, the CJ20ex7.8B 4K UHD lens is compact and lightweight, provides a balanced center of gravity, and incorporates refinements that enhance operability Canon has brought together technology and knowledge accumulated over many years to create the CJ20ex7.8B 4K UHD lens portable telephoto zoom lens. Moving forward, Canon will continue refining its technology and developing even better products to enable customers to capture images of the very highest quality.

CJ20ex78B Product Datasheet

4K Optical Performance

The portable CJ20ex7.8B 4K UHD lens was developed with high index optical glass materials, each having unique dispersion characteristics, helping to minimize chromatic aberrations and geometric distortion. Lens element surface accuracy has been improved significantly over HDTV lenses contributing to the enhanced Modulation Transfer Function (MTF) performance required of 4K imagery. New multi-layer optical coatings combined with new deposition processes produce an outstandingly pristine optical imaging system.

Aspheric lens elements are deployed to a greater extent in the larger diameter elements, contributing to far greater control over geometric distortion and aberrations – especially at the very wide angle settings. Three-part internal focus helps reduce changes in aberrations when focusing to different object distances, while the 170° rotation angle facilitates tight control over any tendency for focus breathing. New, more powerful computer design tools facilitated a greater degree of optimization of multiple optical variables in the lens design.

Compact and Lightweight with Balanced Center of Gravity

Weighing only 4.81 lbs. and measuring 6.69″ (W) x 4.50″ (H) x 9.06″ (L), the portable CJ20ex7.8B 4K UHD lens is similar in size to our 2/3″ HD lenses, while delivering 4K performance. The same shooting style as that of existing 2/3″ HD lenses can be carried over. The center of gravity is close to the mount, lessening strain on the hands and elbows of the camera operator. The ergonomic form factor creates a user-friendly design, including an ergonomic grip design for a comfortable feel, helps to reduce fatigue and make it easy to move the camera about. The new lens is sure to satisfy professionals with its high-level combination of excellent specifications, enhanced optical performance, and outstanding usability.

HD Demand capability

This feature allows for compatibility with a broadcast-use HD demand. It enables the use of the zoom and focus electrical drive system accessories (such as the ZSC-300D and FPD-400D) which are currently used by HD equipment.

Drive Unit

The portable CJ20ex7.8B 4K UHD lens incorporates a digital drive unit, and the high-performance 16-bit encoder supports communication with compatible 2/3″ HDTV cameras equipped with aberration correction functionality, without initializing the lens. Three 20-pin connectors enable high-definition lens metadata output for virtual systems even during full-servo operation. In addition, the low power consumption and a simple display mode (Basic Mode) enhance operability.

Improved Startup and Mobility
The drive unit of the CJ20ex7.8B 4K UHD lens can output accurate lens position data from the moment the power is turned on and does not require initialization, contributing to the quick start when shooting. This is possible thanks to the drive unit’s 16-bit absolute value encoder. Eliminating initialization of the encoder at power-on simplifies calibration when composing virtual and live-action images, and helps to create more accurate composites.

Aberration Correction and Virtual Functions Enabled without Lens Initialization
Aberration correction functions have often been employed on 2/3″ HDTV cameras for broadcast use. The drive unit of the CJ20ex7.8B 4K UHD lens can output accurate lens position data from the moment the power is turned on and does not require initialization, contributing to the quick start when shooting.

Advanced Virtual Operability and Precise Virtual Image Expression
The drive unit of the CJ20ex7.8B 4K UHD lens uses three 20-pin connectors. One of these connectors outputs 16 bit high precision lens positional data, allowing for output even while the zoom and focus servo controllers are in use. This high-performance encoder helps simplify calibration when composing virtual and live-action images, thus resulting in more accurate composites.

Simple Display Operations 
Canon’s unique display-based functions help a variety of operations. We have listened to our customers, and a simplified mode (Basic Mode) makes for easier operation.

Digital Functions

The Canon drive unit integrates a variety of operations, stored digitally, that can be manipulated using the display.

Shuttle Shot 
By memorizing any two focal lengths, the Canon drive unit can automatically “shuttle” between two points, moving in either direction. As an example, this function is effective for shots in which an operator wants to start from a wide angle and then zoom in rapidly on to an object.

Frame Preset
An angle of view can be preset in either of two memories and the lens will zoom at the highest speed, or in a preset zoom speed, to the pre-set position with the push of a simple button. As an example, this function can be effective for situations such as interview programs, where it is necessary to switch between bust shot and wide shot.

Speed Preset
A specific zoom speed can be preset in memory making it possible to repeat the zoom speed as often as you like with the push of a simple button. Using a preset speed when zooming in and zooming out contributes to help create stable images, particularly with slow zooms.

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  • 20x
  • 2.0x
  • 7.8
  • 156
  • 1:1.8 at 7.8-108mm
    1:2.6 at 156mm
  • 1:3.6 at 15.6-216mm
    1:5.2 at 312mm
  • 63.2° x 38.2°
    3.5° x 2.0°
  • 34.2° x 19.6°
    1.8° x 1.0°
  • 0.8m