Frequently asked questions about the workflow with the ALEXA 35 camera
You use our ARRI Reference Tool (ART) to do so. Download ART here.
1. Open the ARRI Reverence Tool. No need to import a clip. Change to the LOOK room.
2. Use the file browser in “My Looks” to find your look file *.alf4 on your storage. Select it. ART automatically applies your look to our Reference Image of Helen and John for reference.
3. Choose “Export 3D LUT” from the tool bar.
4. A pop-up windows opens. Set your LUT size, file name and location to save the file.
Currently you don’t have the possibility to use custom DRTs in-camera. In ALEXA 35 you can choose between different SDR and HDR transforms:
All these DRTs are also included in our official ARRI LogC4 LUT Package, which can also be used in post-production.The functionality for loading custom DRTs into the ALEXA 35 will be released in one of our upcoming camera SUPs.
In the following table you will find the naming of the in-camera DRT and the corresponding 3D-LUT.
Naming in ARRI LogC4 LUT Package | Naming in ALEXA 35 |
ARRI_LogC4-to-Gamma24_Rec709-D65_v1 | REC 709 (SDR) |
ARRI_LogC4-to-Gamma24_Rec2020-D65_v1 | REC 2020 (SDR) |
ARRI_LogC4-to-St2084_1K_Rec2100-D65_DW100_v1 | REC 2100 / PQ (HDR) |
ARRI_LogC4-to-HLG_1K_Rec2100-D65_DW100_v1 | REC 2100 / HLG (HDR) |
With the update to ACES Version 1.3 there was also an update for the ACES IDT for REVEAL (AWG4/LogC4). The ACES Version 1.3 can be implemented by 3rd party vendors e.g. Pomfort already supports ACES 1.3. ACES can be used on the SDI output and in post-production of course. Currently we do not offer an ACES in-camera workflow.
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 workflow and introduced a new color management ("REVEAL") with our ALEXA 35. That means you must use a Log-to-Log 3D-LUT (=without output transform/DRT) inside the look file. Custom DRTs are currently not supported and would end in a double-LUTted look.
We suggest redesigning and visually matching your older Looks/3D-LUTs (designed for LogC3) for ALEXA 35 as it has a completely new color science and dynamic range. There’s also a small guideline “ALEXA 35 – ARRI Look File ALF4”, which explains this task.
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 for ALEV4.
Because the new LogC4 curve is too different from the well-known LogC3 characteristic a conversion of Look files (or 3D-LUTs) is not possible to convert existing ALF2 look files (this applies to 3D-LUTs created for LogC3 as well). Looks/LUTs must be recreated visually in LogC4.
Please note: We highly recommend not to create an inversion of an ALF2 look to create an ALF4 look. This would result in a technically wrong image.
Our ARRI Reference Tool (ART) combines the functionality of our ARRIRAW Converter, ARRI Color Tool and ARRI Meta Extract in one tool. You can extract all metadata form ALEXA 35 into a *.json file.
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 Display Render Transform LUT e.g. for Rec709:
Look Library Look for LogC4 (log-2-log) + ARRI_LogC4-to-Gamma24_Rec709-D65_v1
This example would result in a correct image incl. the look for Rec. 709. Or you combine the Look Library Look with the official ARRI DRT for HDR e.g.
Look Library Look for LogC4 (log-2-log) + ARRI_LogC4-to-St2084_1K_Rec2100-D65_DW100_v1
Our standard texture “K445 Default” is designed to work well for all subject matters and settings, while making the most of the camera’s cinematic strengths. It is forgiving on skin, but also renders images with exceptional clarity and detail, which makes it also a perfect texture for green screen shots and VFX purposes.
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) with a color-space transform.
ALF4 is the new generation look file for ALEXA 35 (ALEV4 sensor). This look file separates the creative grade from the decision which output color space you intend to use. The creative grade is a Log-to-Log 3D LUT that makes changes “in log” to the LogC4 image. The following output color space transformation is currently determined by the respective setting in the camera, you can choose between:
• REC 709 (SDR)
• REC 2020 (SDR)
• REC 2100 / PQ (HDR)
• REC 2100 / HLG (HDR)
All these DRTs are also included in our official ARRI LogC4 LUT Package, which can also be used in post-production.The functionality for loading custom DRTs into the ALEXA 35 will be released in one of our upcoming camera SUPs.
In the following table you will find the naming of the in-camera DRT and the corresponding 3D-LUT.
Naming in ARRI LogC4 LUT Package | Naming in ALEXA 35 |
ARRI_LogC4-to-Gamma24_Rec709-D65_v1 | REC 709 (SDR) |
ARRI_LogC4-to-Gamma24_Rec2020-D65_v1 | REC 2020 (SDR) |
ARRI_LogC4-to-St2084_1K_Rec2100-D65_DW100_v1 | REC 2100 / PQ (HDR) |
ARRI_LogC4-to-HLG_1K_Rec2100-D65_DW100_v1 | REC 2100 / HLG (HDR) |
ALF2 and ALF4 look files are not compatible and cannot be converted.
There’s an easy fix: setting the SDI 1 OVERLAY BRIGHTNESS to 1 (or 2) brings back the green/red bullet (and other colored icons).
We will address the problem in a future SUP for ALEXA 35. Until then, the workaround is needed.
