A ARRIFLEX D-20 é uma camara digital ao estilo de uma câmara de filme. Utiliza um único sensor do tipo CMOS Super 35, o que lhe permite a utilização das mesmas lentes que as normais câmaras de filme 35mm, com a mesma profundidade de campo. Para além da possibilidade de visualização imediata num monitor video, o corpo está equipado com um visor optico, e é compativel com os diversos acessórios ARRI para câmaras de filme. A câmara permite gravar com frame rate variável, e o sinal de saída pode ser em HDTV se funcionar em Video Mode, ou os dados de sensor crus (Raw), no Modo de Filme.

At IBC 2003, ARRI presented the D-20 concept, which has received enthusiastic praise from cinematographers and rental houses alike. Starting in the Fall of 2004, ARRI will place D-20 pre-production units into the field for trial productions to further fine tune the D-20 to the needs and desires of cinematographers and producers. These cameras will be made available through ARRI rental houses to selected productions that are interested in experimenting with innovative workflows and are eager to make use of a modern film style high definition camera.

FILM STYLE CREATIVE OPTIONS BY DESIGN

Since the single 6 Megapixel CMOS sensor at the heart of the D-20 has the same size as a Super 35 mm film aperture, the D-20 uses the same lenses as 35 mm film cameras. This makes the vast range and excellent optical quality of 35 mm lenses available to directors and cinematographers when shooting HD, greatly expanding their creative options.

The resulting images have the same depth of field as 35 mm film, giving film makers the ability to direct the viewer's attention to a specific part of the image, a crucial tool in visual storytelling. Other issues essential to cinematography are also addressed: the D-20 has the ability to capture images at higher speeds, it runs speed ramps, has excellent color fidelity and a high dynamic range.

WHAT IS CMOS?

Like other photoelectric sensors, CMOS (Complementary Metal-Oxide Semiconductor) image sensors are based on an array of photo-sensitive diodes. Each pixel contains one diode that converts light into an electrical charge. Unlike CCDs (Charge Coupled Devices), which output the charge from the pixels serially in a “bucket brigade” process, CMOS image sensors provide a voltage signal at each pixel that is directly proportional to the amount of charge the pixel has collected. Each pixel can be individually addressed to access this information, resulting in a much higher level of flexibility with regards to timing or image format.

WHY CMOS?

Since the D-20 sensor is an ARRI specified design, its performance is custom tailored to digital cinematography and gives ARRI tremendous freedom for future developments. CMOS sensors inherently have superior power efficiency and a natural blooming immunity, plus it is possible to read out any portion of the sensor at any time. This has a wide range of advantages, including the ability to read out high frame rates despite the high pixel count and the ability to run speed ramps. It also means that the recording format can be freely chosen, so it is possible to trade spatial resolution for frame rate. Because CMOS is essentially a more flexible technology than CCDs, ARRI can experiment in the future with new and sophisticated features like higher frame rates or a double read-out of each frame to further increase dynamic range.

A MODULAR AND FUTURE PROOF APPROACH

To ensure that the D-20 is an economically viable investment it is designed in a modular fashion; the sensor can be upgraded when advances in technology offer better performance, and the signal output boards can be exchanged to accommodate future file based interface and storage options. The rest of the D-20, including the housing, the Optical Module (containing the lens mount, mirror shutter, optical viewfinder and camera control electronics) and the internal data bus have been designed to last through many upgrade cycles with traditional ARRI robustness.

To further future proof the D-20, many components have been designed for capabilities far greater than the currently available recording technologies can accommodate. The sensor and the internal data bus, for example, are prepared for frame rates up to 150 fps.

THE OPTICAL MODULE

Users of ARRI film cameras should feel right at home with the bright optical viewfinder and the silent rotating mirror shutter borrowed from the ARRICAM. The optical viewfinder provides not only the highest quality color image for evaluating focus and composition but also allows the operator to see a larger image area than the sensor is capturing. The optical video assist, which is optional, consists of the IVS II optics and electronics from the ARRIFLEX 435 Xtreme. An optical video assist has many advantages in a digital camera, as it provides a video image when the mirror shutter is stopped in the viewing position, showing a larger area than the sensor is capturing and using little power. The Optical Module can be expanded to provide interfaces for many of the extensive range of cine accessories, including wireless lens and camera control or speed ramps with the Remote Control Unit RCU-1. These accessories integrate with the D-20 just like they do with any other ARRI camera.

FLEXIBLE OUTPUT OPTIONS: VIDEO OR FILM MODE

Different productions have different needs, and the D-20 is a flexible tool that can be used in two different output modes: Video or Film Mode.

In Video Mode, the data coming from the D-20 sensor is processed live in the camera. Color reconstruction is performed simultaneously as the 2880 x 1620 pixel grid is converted to 1920 x 1080 resolution. A sophisticated on-board color management system has been implemented to optimize the camera's performance for different lighting situations including blue and green screen work. In Video Mode, the D-20 can supply a variety of standard HD video signals for different recording formats, including HDCAM SR, thus allowing the D-20 to integrate seamlessly into existing HD infrastructures.

In Film Mode, the unprocessed data from the sensor is output directly to the recorder. Similar to a film negative, this data must first be „developed“ in an off-line process involving complex 3D Look Up Tables (LUTs) before it is usable or even viewable. The advantage is that all the image information captured by the sensor is retained, and being able to use more processing power in post production results in higher image quality. The live HD output can still be used for monitoring and as a guide for color grading. The grading parameters can be stored as metadata with the unprocessed image data.