The Arriflex D-20 is a film-style digital motion picture camera made by Arri first introduced in November 2005. The camera's attributes are its optical viewfinder, modularity, and 35mm-width CMOS sensor.
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Overview
The D-20 uses a single CMOS sensor the width of a Super 35 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 Super 35 mm film motion picture cameras. The D-20 captures images in two main modes.
- In Data mode the sensor uses 2880x2160 active pixels generating RAW Bayer-data at 12 bit in a 4:3 aspect ratio. The RAW data then 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 from the full sensor height. Captured data is recorded to either flash or hard drives. Arri hasn´t completed the development of the data mode of the D-20 and it is not presently available, different from Weinberg, SI, red, Dalsa and others, who offer data recording.
It is predicted that by mid 2008 Arri recording technology will develop sufficiently to accommodate the flow of data generated by the D-20.
- In HD Video mode the sensor uses 2880x1620 active pixels to generate an image with a 16:9 aspect ratio. 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). Typically, the D-20 is tethered to a Sony HDCamSR recorder. Other recording options exist, including the Grass Valley flash mag which provides untethered recording of up to 15 minutes per "mag" in RGB 4:4:4. There are no recording option for RAW data as of yet.
The D-20 has a mechanical shutter, variable from 11.2° to 180° or an electronic shutter that simulates a 270° mechanical shutter at 24fps. The camera is capable of running at speeds from 1 to 48fps, though this shall be improved in the future. Numerous components of the camera were borrowed from Arri film camera models (most notably the 435ES), assuring compatibility with Arri film camera accessories and support equipment. Though the D-20 system is capable of variable speeds from 1 to 60 frames per second in Data mode, these are currently limited to 23.976 fps, 24 fps, 25 fps, 29.97 fps & 30 fps in the video mode. The sensitivity of the D-20 in video mode is regulated by the application of LUTs (Look Up Tables) prior to output. With sensitivity settings ranging from ISO 100 to ISO 320 with linear responses, the D-20 also offers log curve options designed to mimic the response of film negative. Unlike some other digital cameras, the D-20 does not offer gain boost, instead relying on the advantages of adding gain in the post production process. The sensitivity of the camera in Data mode is regulated by applying LUTs in the outboard processing of the image.
Distinctive Characteristics
Of the currently available high resolution digital motion picture cameras, among several others, the Dalsa Origin, the SI 2K and the D-20 feature detachable optical viewfinders. The advantages and disadvantages of an optical viewing system over purely electronic ones include: Advantages of optical viewfindes:
- viewfinder resolution limited by optical design only
Disadvantages of optical viewfindes:
- no "what you see is what you get" monitoring possible
- 360/360 degree shutter / full light recording is impossible, therefore reduced sensitivity
A wide variety of electronic viewing options can be added to the camera. Typically, an vector/waveform "onboard" monitor. Uniquely, the D-20 also accepts a traditional film style video assist system, sharing the image available through the optical viewfinder. This can be useful in Steadicam and remote crane applications where visibility outside the sensor capture area is preferable. Like Arri film cameras, the D-20 is modularly constructed. Árri promises that both the mechanical and electronic components are upgradable, however, no upgrade has even been delibvered. Marketing of Arri specifically applies this to the CMOS sensor - however none has been upgraded since the camera became available.
Competition
Other single-chip Super 35 mm film-sized digital motion picture cameras directly in competition with the D-20 include the Panavision Genesis camera, the Dalsa Origin camera and the Red One camera. In the 35mm segment, red is with more than 3000 preorders by far the marketleader. The more expensive japanese 2/3 sensor size cameras of sony and panasonic however are selling much more than all of their 35mm sensor size competition together.
External links
- Official site
- More detailed information can be found on the D-20 page in the Movie Making Manual WikiBook.
- Eric Fletcher's (SOC) experience with the D-20.
- Indie filmmaker reviews Arriflex D-20
