LuttieARRI LUTs for LogC3 and LogC4
ALEXA cameras record LogC3 (ALEXA Mini, Mini LF, AMIRA) or LogC4 (ALEXA 35). The Luttie editor decodes both, curve and ARRI Wide Gamut: set the film engine's Source to your format for free, or use the Camera panel's LogC3 and LogC4 LUTs with Pro. There's no downloadable ARRI pack.
ALEXA 35 · ALEXA Mini LF · ALEXA Mini · ALEXA LF · AMIRA
Convert LogC before you grade it
LogC3 and LogC4 are different curves in different gamuts, so a LUT for one is wrong on the other. LogC3 also shifts slightly with exposure index, which is why ARRI's own LUTs come per EI; Luttie's LogC3 is the EI 800 curve, the one most footage is shot at.
The workflow
Check which LogC you have
The ALEXA 35 records LogC4. The ALEXA Mini, Mini LF, LF and AMIRA record LogC3. Note the EI if it wasn't 800.
Convert to Rec.709
In the Luttie editor, set the film engine's Source to ARRI LogC3 or LogC4, or pick an ARRI LUT in the Camera panel. Elsewhere, ARRI's free LUT Generator makes conversion LUTs for each camera and EI.
Grade on top
Curves, colour wheels, hue curves, film stocks and the scopes all work on the converted image.
Export a .cube
The export dialog says the LUT expects LogC3 or LogC4 footage and writes that into the file, so it isn't put on the wrong clips later. LUT export is Luttie Pro.
No ARRI pack yet
There is no paid ARRI pack. The free LUT library downloads without an account, and the editor runs in the browser with no install, so you can convert and grade ARRI footage without buying anything.
Questions
No. These LUTs convert ARRI footage to Rec.709 and grade it; they aren't ARRI's Classic 709 (K1S1) or an imitation of it. For ARRI's own conversions, use ARRI's free LUT Generator.
No. The ALEXA 35 records LogC4, a different curve in ARRI Wide Gamut 4, so a LogC3 LUT gives the wrong contrast and colour. Use a LogC4 conversion.
LogC3 bends slightly at the toe and shoulder with EI, so the EI 800 conversion is close but not exact at, say, EI 1600. Mid-tones line up; check the highlights on the scopes.
Yes. Open a ProRes clip or a frame in the Luttie editor, set the film engine's Source to LogC3 or LogC4, and grade with every panel. Exporting a clean clip or a .cube LUT needs Pro.
Longer walkthrough: grading LogC footage step by step. Not sure which profile you shot? Find the LUT for your camera.
Other cameras