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CJ12ex4.3B Series

4K UHDxs Portable Lenses

Item Code: 0121T441

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The portable CJ12ex4.3B 4K UHD wide-angle lens offers the world's shortest focal length* of 4.3mm and the world's shortest minimum object distance (MOD)* of 30cm. This makes it possible to create images with extreme wide angles of view, with the shortest focal length for a 2/3" 4K lens. As such, this lens supports subsequent 1920 x 1080 cropping from the 3840 x 2160 camera output providing full HDTV quality. Alternatively, the camera output can be down sampled to provide an even higher HDTV image sharpness.

* Among compatible 2/3-inch 4K broadcast lenses available as of August 25th, 2015.
The portable CJ12ex4.3B 4K UHD wide-angle 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 also exercising 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.
A particular challenge the portable CJ12ex4.3B 4K UHD wide-angle lens design is the built-in 2x optical extender. The insertion of that additional optical subsystem tends to exacerbate optical aberrations. Accordingly, Canon paid the highest attention to the optical design of this unit and as a consequence full 4K optical specifications are protected when the extender is switched in.
Extensive use of 3D CAD-CAM design facilitated an innovative ergonomic design of the portable CJ12ex4.3B 4K UHD wide-angle lens that paid high attention to operator comfort and lessening of fatigue during protracted shooting. The Digital Drive Unit design takes into account the curved human hand that encompasses the unit, with a view of shaping the unit for greater comfort and to better facilitate the actuation of lens controls. The unit shape also provides a wider separation that allows the other hand to more easily adjust the focus control. The drive unit was narrowed and the mounting angle on the lens is set to allow the operator's elbow to settle close to the body, providing an important reduction in fatigue when operating a shoulder mounted lens-camera system.
The special magnesium alloy body was optimized for light weight (a mere 2.1kg) and exceptional durability. Computer simulation of the optomechanical design allowed examination of optimized anti-reflection internal barrel coatings, and structural techniques (light blocking grooves and knife edges) that produced greater control over harmful light reflections within the lens barrel that can be stimulated by strong light sources.
The portable CJ12ex4.3B 4K UHD wide-angle lens utilizes the same standard controllers for zoom and focus operations that have been optimized over decades of Canon HDTV lens developments. The lens also uses the standard Canon 20-pin connector that provides an interface for the digital precision positional information of the zoom, focus, and iris operations required by many external virtual systems



Product Category

ENG Lens

Product Series


Image Composition

Object Image Format

2/3 inch

Aspect Ratio


Zoom Ratio


Focal Length Range

4.3 ~ 52mm

Focal Length Range with Extender

8.6 ~ 104mm (with 2x Extender)

Angular Field of View

96.3° × 64.2° at 4.3mm10.5° × 5.9° at 52mm

Angular Field of View with Extender

58.3° × 34.9° at 8.6mm (with 2x Extender)
5.3° × 3.0° at 104mm (with 2x Extender)

Optical Brightness

Maximum Relative Aperture (F-Number)

1:1.8 at 4.3 ~ 40mm1:2.4 at 52mm

Maximum Relative Aperture (F-Number) with Extender

1:3.6 at 8.6 ~ 80mm (with 2x Extender)
1:4.8 at 104mm (with 2x Extender)

Scene Composition

MOD From Front of Lens

0.3 Meter

Scene Object Dimensions at MOD

76.4 × 43.0cm at 4.3mm6.0 × 3.4cm at 52mm

Scene Object Dimensions at MOD with Extender

38.2 × 21.5cm at 8.6mm (with 2x Extender)
3.0 × 1.7cm at 104mm (with 2x Extender)

Physical Attributes


6.4in (163.5mm)


4.3in (108mm)


9.8in (247.8mm)


4.63lbs (2.1kg)



White Papers

Augmented Creative Control: Innovations in Focus Demand and Zoom Demand Controllers for 4K UHD Long Zoom Field Lenses
Today, large format lens-camera systems have been adopted in many broadcast television productions and producers, directors, and camera operators have now become both attached to, and skilled in, the cinematic imagery and practices supported by these systems. In particular, the “rack focus” is much used in movie and episodic television dramas. This entails a subtle change in depth of field that reveals some new detail (can be an item or another human subject) in a scene – by careful manual operation of the lens focus control. Operational implementation involves changing the focus of the lens during a continuous shot – and this can be small or large changes of focus. If the focus is shallow, then the technique becomes more noticeable. It does demand precision control over focus accuracy.

Very wide rotation angles – typically 270 degrees or greater (from MOD to Infinity focus extremes) – has long been established in the cine lenses (both primes and zooms) used in the motion picture film world.
Role of the 2/3-inch Image Format in 4K UHD Production
This paper is intended to provide a background to the emergence of 2/3-inch lens-camera systems for 4K UHD production and the optical performance expectations of associated 4K lenses. The paper will review Canon’s involvement in the development of those lenses and will describe our initial 4K UHD lens family and the associated design strategies to achieve this impressive level of optical performance. The paper will explain the unprecedented strategy of introducing two categories within this new 4K UHD lens family – namely, 4K and 4K PREMIUM. The distinct performance difference between the two reflects Canon’s recognition that different 4K program genres will require different levels of overall cost / performance.
Lens Strategies for the era of 4K UHD Digital Motion Imaging
It was probably inevitable that broadcasters would begin to explore the possibilities of 4K UHD for the globally popular world of outside broadcast sports coverage; and indeed, recent years have seen a great deal of related experimental projects. The 4K UHD lens issue soon surfaced as the limitations of presently available Super 35mm zoom lenses quickly became apparent.

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† Prices and specifications subject to change without notice. Actual prices are determined by individual dealers and may vary.

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