Based on the ARRI LUT Generator I have created a minimal OCIO config of ARRI K1S1 for full CG projects. This is one of the most popular LUTs ever created in its most minimalistic and simple form:
- Inputs (textures) are in "linear"
- Rendering and Nuke working space are also in "linear"
- View Transform is for Rec.1886 display
There is no need to go wide gamut or do anything complex to craft beautiful images. Enjoy!
Original files (encoded in "linear-AP0") are available here.
- Reference color space is XYZ which is the base of all colourimetry
- All matrixes have been generated using colour-science with CAT02
- "linear" stands for "linear_bt.709"
- "cineonlog_rec709" can be used for a matte-painting workflow in Photoshop
- "logc3_arriwg3" is the shaper space. It can be used for color timing and some log operations (such as sharpen)
- Substance_painter roles were set following this page
- An inverse of the View Transform has been provided even though it is not perfect
- Please note that the inverted LUT was not ARRI-originated (I respected the naming convention from this guide)
- One may easily add several colorspaces or displays for HDR output if needed (such as "p3_d65_pq")
- 87 looks from the ARRI Look Library have been uploaded
- The use of Looks is highly recommended with ARRI K1S1
- To use one of the looks, you need to combine it with a View. Like this for instance:
- !<View> {name: ARRI K1S1 Vibrant, colorspace: ARRI K1S1 - Rec.709 - 2.4 Gamma, looks: 5210 Vibrant}
| Name | Author | Release date | Observations |
|---|---|---|---|
| ACES | AMPAS | 2016 | Color Encoding System developed by the Academy |
| Filmic | Troy Sobotka | 2017 | Original Blender Color Management used on this movie |
| RED IPP2 | Graeme Natress | 2017 | RED Image Processing Pipeline explained here |
| Sony Venice | Sony / Picture Shop | 2022 | LUT files made in partnership with Picture Shop |
| ARRI Reveal | Sean Cooper | 2022 | The new ARRI Alexa35 workflow described here |
| Tony | Tomasz Stachowiak | 2023 | A cool-headed display transform |
| AgX Blender | Eary Chow | 2023 | Blender Color Management used on this video game |
| TCAMv3 | Daniele Siragusano | 2024 | Baselight Color Management Workflow explained here |
| AgX SB2383 | Troy Sobotka | 2024 | Minimal AgX OCIO Config using Linear BT.709 |
| JP-2499 | JP Zambrano | 2024 | A popular picture formation pipeline described here |
| Open DRT | Jed Smith | 2024 | State-of-the-art Color Management Workflow |
- On January, 1st of 2025, Joseph Goldstone provided the following information on the OCIO slack.
- K1S1 could be constructed as a concatenated EI-specific inverse LogC3 curve, a matrix from AWG3 to Rec. 709, a tonemapping operator and a gamma correction curve. That's how the original ALEXA cameras worked, starting with SUP 3.0 in 2011.
- ALF-2 files came in with the ARRI AMIRA (a documentarian targeted camera) around 2013, and entered the mainstream ALEXA line with the ALEXA Mini shortly thereafter.
- The equations underlying the ALF-2 LUT were never made public, but what we always emphasized was that if you took something screaming red (think: Sunkist raisins packaging) with certain spectral power distributions under certain lighting, where K1S1 would way oversaturate, the base ALF-2 LUT pulled the reds in.
- It could do this because, unlike the mainstream ALEXA line up to (I think) the ALEXA SXT, the AMIRA and the Mini had a 3D LUT in the processing path whereas the others had only a LUT-matrix-LUT path.
- The improvement between K1S1 and base ALF-2 was so small, and the circumstances under which one would see the differences so rare, that colorists worldwide kept using K1S1. They did this even when we (from the beginning) embedded the ALF-2 base LUT at the start of every clip those cameras produced.