What SDR and HDR output transforms does an ALEXA 35 apply in camera under ARRI Color Management, and which LUT files correspond?

ARRI documents four fixed in-camera display render transforms for ALEXA 35/265 under ARRI Color Management: Rec 709 (SDR), Rec 2020 (SDR), Rec 2100 PQ (HDR), Rec 2100 HLG (HDR), each with an equivalent file in the official LogC4 LUT package. A July 2025 naming guideline adds an HLG variant with 203 nit diffuse white (BT.2408) and renames the PQ/HLG colour-space tag from Rec2100 to Rec2020 in file names, while the workflow FAQ still shows the older names. ARRI's pages do not publish tone-map or roll-off parameters for these DRTs. Curator qualifications: Quotes and file names verified. The producer's rights_conflicts entry is a naming discrepancy, not a rights conflict. The 2025-07-10 guideline documents the change itself ('Changed Color Space Tags from Rec2100 to Rec2020'), so the FAQ's Rec2100 names are stale relative to the guideline. This is a supersession relationship, not two contradictory authorities. Reclassify the S9-vs-S12 discrepancy as a documented supersession: the 2025-07-10 LUT naming guideline renamed the PQ/HLG colour-space tags (Rec2100 to Rec2020) and added an HLG DW203 variant. The FAQ (read 2026-10-22) still shows the pre-rename names. It is not a rights conflict; remove it from rights_conflicts_for_curation. Add the HLG DW203 file name (ARRI_LogC4-to-HLG_1K_Rec2020-D65_DW203_v1_65.cube) as the BT.2408 203-nit variant. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

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