ALEXA XT B+W
ARRI Rental’s black-and-white ALEXA produces stunning, high resolution monochrome images
Representing the state-of-the-art in digital monochromatic cinematography, the ALEXA XT B+W combines a modified ALEV III ALEXA sensor with all the features of an ALEXA XT, including in-camera ARRIRAW recording up to 120 fps, 4:3 sensor and LDS PL mount. The rich, monochromatic images produced by the camera display more contrast and increased spatial resolution, with 15 stops of dynamic range.
Sensor configuration and filter system
The ALEXA XT B+W sensor assembly has no Bayer mask, optical low pass filter (OLPF) or IR block filter, allowing each photosite to capture the full spectrum of visible light and upping the base sensitivity to 2000 ASA. Images from the camera are therefore sharper and display more contrast than those from a standard ALEXA with the color wound down, delivering a classic black-and-white look that is very much like a 35 mm camera loaded with panchromatic film. In addition to black-and-white, the camera can also be easily configured to capture infrared. In this mode the camera only 'sees' the reflected, infrared, non-visible light. These images appear radically different, producing white foliage, blemish-free skin, black eye pupils and moody dark skies. Switching between these modes can be done easily through the use of two new interchangeable internal filters - a BG39 filter for stunning black-and-white or a BG87C infrared pass (visible light block filter) for dramatic infrared.
The ALEXA XT B+W utilizes the same in-camera ARRIRAW recording system as the ALEXA XT family, recording to 512 GB XR Capture Drives. The native resolution of ALEXA XT B+W images is the same as a regular ALEXA recording ARRIRAW – i.e 16:9 format at 2880 x 1620 and 4:3 format at 2880 x 2160. Spatial resolution, sharpness and image contrast however, are all improved over a regular color ALEXA XT. ProRes HD/2K and DNxHD recording is not supported in camera, but these file types can be quickly and efficiently generated off-line during ingest and archival using Codex VFS software that has been optimised for the ALEXA XT B+W.
Since the sensor has no Bayer mask, images need to be processed using the ARRI SDK / ARC 3.0 reference tools or other ARRI-approved image processing products. ARRIRAW images captured on ALEXA XR Capture Drives can be quickly and easily off-loaded; then 2K Log C DPX sequences can be rendered from the ARRIRAW master, prior to transcoding to editorial proxy formats such as ProRes or DNxHD.
The recommended “best practice” workflow in terms of delivering optimum quality, reliability, flexibility and processing speed on-set or near-set is to use the Codex VFS, Dual dock or Vault.
For commercial or music video productions more familiar with using a ProRes mastering format, full resolution 2.8K ProRes master files can be very quickly and efficiently generated via the Codex VFS during the offloading of B+W camera ARRIRAW footage into the Vault. An ARRIRAW archive copy can also be stored if required, without slowing down the process of creating editorial files.
For more ALEXA XT B+W sample footage watch:
• Music promo OUT OF MY HEAD for John Newman. Shot by cinematographer Richard Stewart.
• Music promo TOUT DANS LA TÊTE for French rapper Zoxea. Shot by cinematographer Arthur Briet.
• Music promo NEVER LANDS for Night Flowers. Shot by cinematographer Alexander Galt.
• Infrared shoot AUDI X FACTOR. Shot by cinematographer Bill Bennett, ASC.