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 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 4 (LogC4) or ALEXA...
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. For ALEXA and AMIRA cameras this is...
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...
Look files for ALEXA 35 (*.alf4 files, log-to-log).
To use the Look Library in post production, download the Log-to-Log version for ALEXA 35 here .Please keep in mind that those need to be need to be combined with the ARRI official...
Collection of log-to-log 3D LUTs for post production. Use for footage shot with ALEXA35.
Collection of log-to-log 3D LUTs for post production. Use for footage shot with ALEXA Classic, ALEXA Mini, AMIRA, ALEXA 65, ALEXA LF, or 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...
This is not an error! You have chosen to record in “Log C” – ARRI’s native color encoding. Opposed to a “video” image (in REC 709 color space) Log C maintains more details in the...
The Look Library "for post production" is available as Log-to-Log 3D-LUTs (*.cube) for LogC3 and LogC4 on our Look Files Website . Some 3rd party applications are able to...
Generally speaking you need to export the look as a 3D-LUT and build this into an ARRI Look File. For ALEXA 35 this needs to be a Log-to-Log 3D-LUT based on actual Logc4 footage; the...
Look files for ALEXA Mini, AMIRA, ALEXA SXT, ALEXA 65, ALEXA LF, and ALEXA Mini LF (*.aml files, log-to-Rec 709).
Images in the camera are processed in 16 bit linear and then encoded in 12 bit log on the recording medium.
The ARRI Look Library is part of the camera software of ALEXA and AMIRA cameras: it is available in ALEXA 35, ALEXA Mini, and AMIRA. Look Library Looks (ALF-2 format) are compatible with ALEXA SXT,...
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
As explained in the answer "What is Log C?" the maximum value of the Log C function depends on the exposure index. In a video image, however, one wants to have the clipping...
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...
Wide gamut is a generic term for color gamuts that are larger than Rec. 709, i.e. P3 or Rec. 2020. ARRI Wide Gamut 3/4 is the name of the color encoding space used in combination with...
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...
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...
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, 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...
All 3D-LUTs you want to use in ALEXA 35 need to be converted to an ARRI Look File 4. You can use our ARRI Reference Tool to convert the LUT for ALEXA 35. Keep in mind that we have changed our look...
ALF2 look files are designed to work with ALEXA Mini, ALEXA SXT, ALEXA 65, ALEXA LF, ALEXA Mini LF, as well as AMIRA (all using our ALEV3 sensor). They combine a creative grade (CDL or custom LUT)...
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...
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...
introduced: PQ and Hybrid Log Gamma (HLG).
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...
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...
The ARRIRAW T-Link (Transport Link) had been developed for ARRIFLEX D-20/D-21 (and was used in early ALEXA cameras/"ALEXA Classic") to utilize a standardized HD-SDI interface...
ALEXA 35 uses our new REVEAL Color Science. REVEAL introduces a new Log C curve (LogC4) for the new ARRI Wide Gamut 4 color space to make use of the advancements made in sensor technology...
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...
