Flexible Output Options

Data recorders that can record and play back the ARRIRAW T-Link signal can be certified by ARRI.

ARRI ARRIFLEX D-21 / D-21 HD

Different Productions Require Different Outputs

Different projects have different production requirements, budgets and distribu- tion channels; the equipment chosen has to be flexible enough to accommodate those differences. The unique construction of the ARRIFLEX D-21 and D-21 HD allows for various output signals to be generated, accommodating diverse production needs and pipelines.

Both the D-21 and the D-21 HD are capable of generating the Mscope signal, as well as a number of HD signals. HD output options include 'Linear' or Loga- rithmic output, 4:2:2 YCbCr or 4:4:4 RGB, Normal or Extended Range, as well as an optional fiber optic link. These output formats are well established standards that integrated the cameras seamlessly into the existing HD infrastructure.

Additionally, the D-21 is capable of generating a raw data signal that can be output concurrently with the HD signal. The uncompressed, 12 bit raw Bayer data from the D-21's 4:3 sensor is thus available in full resolution. The ARRIRAW T-link (Transport Link) is a method of transporting the ARRIRAW data over a standard dual link HD-SDI connection. The data files which result from process- ing of the ARRIRAW recordings are as easy to grade as those scanned from film because they have the same pixel raster and colorimetry as film scans.

ARRIRAW T-Link

One of the obstacles that has held back the use of raw data in the past has been the problem of how to get data easily from the camera to a recorder. ARRI engineers have found a way to utilize a standard dual link HD-SDI connection to transport the raw D-21 Bayer data. This transport method is called "AR- RIRAW T-Link" (Transport Link). It allows any recorder capable of recording an uncompressed dual link HD-SDI stream to record raw D-21 Bayer data, greatly simplifying the raw data workflow for manufac- turers and users alike. The properties of the dual link HS-SDI connection are defined in SMPTE 372M. The standard specifies a maximum data rate of 2.97 Gb/s, which is enough bandwidth to carry the 12 bit D-21 raw Bayer data. SMPTE 372M also defines a number of standardized source signal formats to be sent through two BNC cables (affectionately known as Link A and Link B).

One of those source signal formats is the RGBA format. RGBA stands for red, green and blue plus an alpha channel, technically called 4:4:4:4 (R'G'B'+A)/10 bit. The ARRIRAW T-Link works by mapping the 12 bit raw Bayer data into this RGBA data stream, so that it can be transported via a dual link HD-SDI connection.

Any recorder that is capable of recording a SMPTE 372M compliant RGBA signal and playing it back without compression or further encoding can record this signal. If the signal is recorded by a data re- corder, the additional option of a live preview exists. The data recorder can extract the original D-21 raw Bayer data out of the RGBA data stream, and use a real-time image reconstruction algorithm to display the 4:3 image as a 1440 x 1080 preview HD image. If anamorphic lenses are used on the D-21 a suitably "de-squeezed" image can be displayed on an HD monitor.

A similar but more refined process is used in postproduction. The original raw Bayer data is extracted from the RGBA stream, and advanced image reconstruction algorithms are used to reconstruct a pristine image in HD, 2K or 2.8K. Doing this in post has the added advantage that it does not have to be done in real-time, so a significantly better image quality and greater flexibility are possible. Note that throughout the whole process, the image always stays uncompressed, at the highest quality.

ARRIFLEX D-21 HD specifications

The ARRI ARRIFLEX D-21 HD is a distinguished digital cinematography camera that has made remarkable strides in the film industry since its introduction. Designed for professional filmmakers, it combines traditional film aesthetics with modern digital technology, making it a compelling choice for various cinematic endeavors.

One of the most notable features of the D-21 is its image quality. The camera is equipped with a Super 35mm-sized sensor, which is pivotal in achieving the characteristic depth of field and wide field of view synonymous with 35mm film. This sensor allows filmmakers to exploit the rich visual language that has been a hallmark of high-end cinema for decades.

To ensure maximum flexibility and integration in post-production, the D-21 captures images in a high-definition format with a resolution of up to 1920 x 1080 pixels. This resolution provides filmmakers with the ability to work with detailed and vibrant footage, making it suitable for various distribution formats, including theatrical releases and broadcasting.

The D-21 is also notable for its superior dynamic range, which extends the capabilities of the camera in capturing details in both highlights and shadows. This feature is particularly beneficial for filmmakers working in challenging lighting scenarios, as it permits greater creative latitude during the shoot and post-processing.

In terms of technology, the D-21 incorporates several advanced features. One such feature is its unique color processing system, which allows for precise control over color grading. Filmmakers can capture the scene with accurate color reproduction, thus minimizing the amount of post-production color correction required.

Moreover, the camera supports a modular design, enabling customization to fit various shooting styles and requirements. This includes interchangeable lenses, allowing filmmakers to utilize different focal lengths and depths of field without restriction.

The ergonomic design of the D-21 makes it user-friendly, accommodating the needs of professional crews during long shooting days. It is compatible with a range of accessories such as matte boxes, follow focus systems, and wireless monitoring solutions.

Overall, the ARRI ARRIFLEX D-21 HD stands as a bridge between traditional film and the digital future. Its combination of superb image quality, advanced technology, and a user-centric design cements its position as a preferred choice for many cinematographers striving for visual excellence in their storytelling.