Arri Alexa

Arri Alexa camera.

The Arri Alexa (stylised as ALEXA) is a film-style digital motion picture camera system made by Arri first introduced in April 2010. The camera marks Arri's first major transition into digital cinematography after smaller previous efforts such as the Arriflex D-20 and D-21. It features modularity, PL mount lenses, a Super 35 sized CMOS sensor shooting up to 2880×2160 resolution and supports uncompressed video or proprietary raw (ARRIRAW) data.[1]

Overview

Arri Alexa camera being used with Master Steadicam.

The camera has several methods of recording, including SxS cards, CFast 2.0 cards and SXR Capture Drives at resolutions up to 2880 x 2160 pixels in either Rec. 709 or Log-C to ProRes or ARRIRAW codecs. Alexa camera owners can purchase additional software "Licenses" that will unlock different capabilities of the Alexa Camera including High Speed 120fps recording, DNxHD codec and 4:3 "Open Gate" Mode for anamorphic lenses.

The camera is designed for use in high budget feature films, television shows, and commercials, and competes with Red Digital Cinema's line of high end cameras such as the Epic Dragon and Weapon Dragon.

Model range

The range of models has been expanded through the camera's lifetime. In 2012, there were five basic models of the Alexa:

Alexa

The first camera of the Alexa product family. The ARRI ALEXA’s CMOS Super-35mm sensor is rated at ISO 800. That sensitivity allows the camera to see a full seven stops of over exposure and another seven stops of underexposure, an unprecedented Dynamic Range. To take advantage of this, ARRI offers both industry-standard REC709 HD video output as well as the Log-C mode that shows the entire range of the chip’s sensitivity, allowing for an extreme range of color correction options in post.

Alexa Plus

The ALEXA Plus adds integrated wireless remote control, the ARRI Lens Data System (LDS), additional outputs, lens synchronization for 3D, and built-in position and motion sensors.

Alexa Plus 4:3

The ALEXA Plus adds integrated wireless remote control, the ARRI Lens Data System (LDS), additional outputs, lens synchronization for 3D, and built-in position and motion sensors and a 4:3 sensor making it ideal for anamorphic cinematography.

Alexa M

The Alexa M has its imaging and processing unit broken down in two parts to be small, compact and lightweight for 3D rigs and other uses where size is a concern.

Alexa Studio

The Alexa Studio features an optical viewfinder, mechanical shutter, and a 4:3 sensor for anamorphic cinematography.

Alexa XT

In February 2013,[2] the range was renewed as Alexa XT (XT standing for extended technology). This range is upgraded versions of the original Alexa cameras, which are equipped with a so-called XR module, which replaces the SxS module on the cameras, and allows direct RAW recording without the need for an external recorder. This module records on dedicated SSD drives. Further improvements are an internal ND filter unit, a 4:3 sensor and a quieter cooling fan. The range accordingly comprises the Alexa, the Alexa XT, the Alexa XT M, the Alexa XT Plus, the Alexa XT Studio, and the Alexa Fiber Remote. Existing cameras can be upgraded with the XR module for internal RAW recording.[3]

Alexa 65

On 21 September 2014 at the Cinec convention in Munich, Arri announced the Alexa 65,[4] a 6k 65mm digital cinema camera. The camera will be available for rental only, like those from competitor Panavision. Arri announced details of the camera on their Arri Rental Group website:

At the heart of the ALEXA 65 is the A3X sensor; the largest high-performance motion picture sensor available on the market today. The sensor has a 54.12 mm x 25.59 mm active imaging area, which is even larger than the film gate of ARRI’s 765 65 mm film camera.
— ARRI Rental Group, arrirentalgroup.com

The first production to use the camera was Mission Impossible - Rogue Nation, which was used to shoot the underwater sequence, and around forty percent of The Revenant,[5][6] additionally, the Alexa 65 will be used to film sequences in the upcoming Star Wars spinoff film, Rogue One, The Huntsman and The Divergent Series: Allegiant.

The first feature films to be shot entirely with the camera were Snowden and The Great Wall.

In April 2015, it announced that Captain America: Civil War would feature 15 minutes of footage shot using a version of the camera built in collaboration with IMAX. In May 2015, Marvel Studios announced that the two-part Avengers: Infinity War will be shot entirely with the new camera, marking the first time a full-length theatrical film will be shot entirely with Imax/Arri 2D digital cameras.[7]

Alexa Mini

On 24 February 2015 Arri announced the Alexa Mini. It has the same sensor as the other Alexa cameras. It features in-camera recording to CFast 2.0 cards, 200 FPS and 4K UHD in-camera upscaling.

Alexa SXT

On 18 March 2015, Arri announced the SXT line of Arri Alexa cameras which will support in-camera upscaling of Apple ProRes to 4K resolution and Rec. 2020 color space.[8][9] Arri also announced the SXR module which can upgrade XT, XT Plus, and XT Studio cameras with the SXT features.[8][9]

Sensor information

Arri Alexa being used on the set of Law & Order: SVU

The Alexa's ALEV III sensor has 3392×2200 effective pixels used for generating an image, 2880×2160 pixels are generally used for recording on the Alexa Studio and M in 4:3 mode, and 2880×1620 pixels are used for recording on the regular Alexa and other models in 16:9 mode, the rest of sensor is used for lookaround in the viewfinder. Alternately the full sensor resolution may be employed in 'Open Gate' mode for resolution demanding situations.

Director Robert Tur with an Alexa-Plus camera equipped with an 18 mm Master Prime lens on the set of SIS.

Recording media

The Arri Alexa can record to 1920×1080 ProRes 422 or ProRes 4444 on SxS Cards or 2880×1620 ARRIRAW to external recording devices. The Arri Alexa Firmware 7 increases the resolution on the SxS cards to 2k ProRes 4444 (previously 1080p)

ArriRaw

ArriRaw is a raw codec similar to CinemaDNG that contains unaltered Bayer sensor information, the data stream from the camera can be recorded via T-link with certified recorders like those from Codex Digital or Cineflow.

The ArriRaw format (along with the other recordable formats) contains static and dynamic metadata. These are stored in the header of the file and can be extracted with the free web tool metavisor[10] or with the application Meta Extract provided by Arri. Of particular importance for visual effects are the lens metadata, which are stored only when Arri's lens data system (LDS) is supported by the lens used.

Reception

According to cinematographer Roger Deakins, the Alexa's tonal range, color space and latitude exceed the capabilities of film. "This camera has brought us to a point where digital is simply better", says Deakins.[11] Deakins used the camera to shoot the James Bond film Skyfall.

Due to the camera's simplicity of use and high image quality, quite a few network television shows have been shot with the Alexa.[12]

Similar cameras

References

External links

Wikimedia Commons has media related to Arri Alexa.
This article is issued from Wikipedia - version of the Sunday, March 20, 2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.