Log C
FAQ
The Log C curve is a logarithmic encoding of the scene, meaning that the relation between exposure measured in stops and the signal is constant over a wide range. Each stop of exposure...
The Hybrid Log Gamma curve is an HDR standard defined by NHK and BBC. It is specified in ITU Rec BT 2100. The HLG specification offers a degree of compatibility with legacy displays by more...
White paper - not valid for ALEXA 35
No. Going from ARRIRAW to 12 bit Log C encoded files means no information loss. ProRes is capable to hold all the information that is inside an ARRIRAW frame in ARRI Wide Gamut color space.
Images with Log C encoding in the ALEXA/AMIRA-specific wide gamut color space provide the camera's full latitude in an unconfined color space. Log C grading is very similar...
16 bit linear encoding is neither efficient nor necessary for recording images. Images can be converted from 16 bit linear to 12 bit log without any loss of information or quality, but with...
Collection of log-to-log 3D LUTs for ALEXA 35
Collection of log-to-log 3D LUTs for ALEXA Classic, ALEXA Mini, AMIRA, ALEXA 65, ALEXA LF, and ALEXA Mini LF
The looks can be adjusted using CDL parameters after duplicating them in the camera. This way it is possible to use ARRI Look Library looks as a basis to create new adjusted versions which are...
The ARRI Look Library is part of the camera software of ALEXA and AMIRA cameras: it is available in ALEXA 35, ALEXA Mini LF, ALEXA Mini, and AMIRA. The Look Library is available in...
This is not an error! You have chosen to record in “Log C” – ARRI’s native color encoding. Opposed to a straight encoding to a “video” image (in REC 709 color space) Log C maintains...
Images in the camera are processed in 16 bit linear and then encoded in 12 bit log on the recording medium.
When viewed directly, Log C footage looks flat with desaturated colors, LogC4 might seem underexposed. To get an image with a grayscale characteristic and color reproduction that is visually...
Currently, there are three distribution standards for HDR video to the home: HDR10 Dolby Vision Hybrid Log Gamma And one standard for distribution to the cinema: Dolby Vision Cinema
DCI-P3 color space has been removed from the ALEXA camera menu for reasons of simplicity. A conversion LUT, Log C to DCI-P3, can be generated via our LUT Generator .
Wide gamut is a generic term for color gamuts that are larger than Rec. 709, i.e. P3 or Rec. 2020. ALEXA Wide gamut is the name of the color encoding space used in combination with Log C.
You do not need any special software. Any system that can work with Log C data and 3D LUTs can be used to generate an HDR master. You may need special software, however, to create specific...
Use an HDR monitor on set to judge your images in HDR. ARRI provides look files and 3D LUTs that convert the Log C image into HDR using the SMPTE ST-2084 („PQ“) encoding. These look files...
At this point in time the WiFi of the ALEXA LF and ALEXA SXT W offers only access point mode, which means that external devices can connect to the ALEXA WiFi network, but the ALEXA cameras with...
ARRI Look File 1 offers CDL-like controls as well as printer lights, saturation and a user-definable tone mapping curve. The ALF-1 does not apply LIFT/Gamma/Gain before but after the...
If your camera is not calibrated, there is a link in the ARRI AMIRA license shop to log a service request with an ARRI service center, for those whose camera was purchased direct from ARRI.
Yes. ARRI provides a downloadable zip file containing a sample ARRIRAW file and derivative images , including a Log C DPX frame, an ACES OpenEXR frame and display-ready frames. These can be...
Yes, some color grading tools offer such features. The quality most likely will not be as good as working from Log C original files (or film scans). But since there is a lot of existing SDR...
ARRIRAW is the raw format of ARRI's digital cameras. Its file extension is *.ari or *.mxf. The sensor readout of our ALEV3 and ALEV4 sensor is a raw Bayer frame provided as uncompressed, 12...
The ALEV4 sensor offers 17 stops and the ALEV3 sensor 14+ stops of dynamic range with a base sensitivity of EI 800. This dynamic range is available in both ARRIRAW and Log C encoded ProRes...
While HDR displays are just now becoming available, ARRI digital cameras have always captured a high dynamic range far exceeding the capabilities of displays. So ARRI digital cameras have been...
All up-to-date VFX tools have native support for ARRIRAW processing. For applications without ARRIRAW support, the footage can be processed to e.g. 10 bit log *.dpx or 16 bit floating-point...
Use the ARRI Color Tool (ACT) to create ARRI’s Look File 2 to use in ALEXA SXT, ALEXA Mini and AMIRA. Based on a Log C-clip or a *.dpx still frame you can create looks using Color Decision...
The ALEXA Mini LF allows recording in ARRIRAW and Apple ProRes Log C. It is not possible to record a baked-in look, as that would use too much processing power. However, the whole ARRI Look...
There is one general HDR standard (Rec 2100) and a number of different distribution standards, of which three are the most popular (for a detailed description of all standards see our "HDR...
Two general requirements must be met to experience HDR at home: a) your TV set must be HDR compatible. The first displays compatible with one of the three main HDR distribution standards (HDR10...
60 fps), p - 3G 444 HD (SMPTE ST425-3, up to 30 fps), p - 6G 422 UHD (SMPTE ST2081-10, up to 30 fps), p SDI 1 SDI 2 Configuration Fully configured or clean Clone of SDI 1 or clean Output...
A HDR workflow is not much different from current workflows. The ALEXA Wide Gamut/Log C (or ARRIRAW) footage is loaded into a color correction system. A 3D LUT is then used to convert...
The ARRIRAW T-Link (Transport Link) has been developed to utilize a standardized HD-SDI interface for sending raw data from the camera to an external recorder. The camera packs the ARRIRAW data...
introduced: PQ and Hybrid Log Gamma (HLG).
MON OUT 1 and MON OUT 2 can each output either a 422 1.5G single link HD-SDI (1920 x 1080) signal or a 422 6G single link UHD-SDI (3840 x 2160) signal. MON OUT 3 can output a 422 1.5G single link...
ARRI offers a software development kit (SDK) for ARRIRAW processing that software vendors can incorporate into their application. ARRI also supports vendors who wish to implement the ARRIRAW...
White paper
not be happy with the SDR. When using the 3D LUTs from ARRI for HDR and SDR grading and performing all grading decisions in Log C space (the 3D LUT is used as the last grading step)...
AMIRA supports workflows for live multi-camera productions in HDR according to BT.2100 Hybrid Log Gamma (HLG) or Perceptual Quantizer (PQ) Cost efficient multicast HDR and SDR workflow...
The following are the default looks of the camera: ARRI 709 - renders the video image according to the ITU.R-BT709 standard ALEXA Classic 709 - matches the color reproduction to the ARRI ALEXA ARRI...
