Wednesday, August 15, 2007
Arriflex D-20
The Arriflex D-20 is a film-style digital motion picture camera made by Arri first introduced in November 2005. The camera's main attributes are its modularity and the size and type of its sensor.
The D-20 uses a single CMOS sensor the size of a Super 35mm film gate aperture. Effectively the D-20, when used with current 35mm PL mount motion picture lenses, yields the same field of view and depth of field as that of traditional 35mm film motion picture cameras.
The D-20 captures images in two main modes.
In Data mode (4:3 aspect ratio) the sensor has 3018x2200 active pixels generating RAW Bayer-data at 12-bits. The RAW data needs to be processed outboard to generate a full color image. A delivery aspect ratio for theatrical release, commonly 1.85:1, is achieved by cropping from the original image, similar to the cropping necessary when shooting 35mm film. In Data mode the sensor size also allows for the use of anamorphic lenses, producing the 2.35:1 widescreen aspect ratio.
In HD Video mode (16:9 aspect ratio) the sensor uses 2880x1620 active pixels. This output is 1920x1080 pixels in either YUV 4:2:2 10 bit (via single link HD-SDI) or RGB 4:4:4 10 bit (via dual link HD-SDI).
The D-20 has a mechanical shutter, variable from 11.2° to 180° and an electronic shutter variable from 66° to 360° at 24fps. The camera is capable of running at speeds from 1 to 60fps, though this is currently limited. Numerous components of the camera were borrowed from Arri film camera models (most notably the 435ES), assuring full compatibility with most of the film camera accessories.
Film Shot with D-20:
Advantages
Like the Dalsa Origin, the D-20 features a detachable optical viewfinder. Digital and electronic viewing systems have different advantages.
optical viewfinder advantages
abiity to use camera to set framing without having connection to a power supply
extremely high viewfinder resolution
electronic viewfinder advantages
monitoring the final image after capture. optical viewfinder monitor before capture and therefore don't show what the camera records, but what the lens shows.
electronic viewfinders can display more information (as foucs charts, wavemeter, zebra etc) which help the dp.
both systems, electronic and optical can have
fractionally greater field of view than the sensor, allowing for more accurate and predictive framing
ability to optically zoom in within the viewing system to check critical focus.
the two points above are only available on very good electronical viewfinder/camera systems. Additionally, a wide variety of electronic viewing options can be added to the camera, giving it many advantages of purely electronic viewing systems.
Like Arri film cameras, the D-20 is modularly constructed. Both the mechanical and electronic components are upgradable. This also applies to the sensor, which can be changed as advances are made.
Limitations
At present the Data output and variable speed capabilities of the camera are disabled, awaiting upgrades from Arri.
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