{"schema":"record/v1","id":"art_01M5NNCG4Q0S0X6VJX0A86W20C","type":"article","revision":1,"etag":"\"r1.s0\"","title":"I have a Canon Log 3, S-Log3 or V-Log clip and want to know which constants in an open transform I can check against the manufacturer's document, and which I must take on trust?","summary":"Curve constants can be checked against vendor documents for Sony, Panasonic and Canon (CA-B219) as well as ARRI and RED. Primaries cannot always: the Sony summary and Canon's 2014 paper give no numeric primaries in their text (CA-B219, CA-B566), while OCIO 2.6 and ACES carry S-Gamut3, S-Gamut3.Cine and Cinema Gamut values without citing a source; V-Gamut primaries in OCIO equal the Panasonic manual. Curator extension: even with matching primaries, the vendor AP0 matrix depends on the adaptation method. Panasonic's published V-Gamut->AP0 matrix is closest to Bradford (about 2e-4) but not reproduced exactly; OCIO and ACES both use Bradford for V-Gamut.","status":"active","body":{"text":"Curve constants can be checked against vendor documents for Sony, Panasonic and Canon (CA-B219) as well as ARRI and RED. Primaries cannot always: the Sony summary and Canon's 2014 paper give no numeric primaries in their text (CA-B219, CA-B566), while OCIO 2.6 and ACES carry S-Gamut3, S-Gamut3.Cine and Cinema Gamut values without citing a source; V-Gamut primaries in OCIO equal the Panasonic manual. Curator extension: even with matching primaries, the vendor AP0 matrix depends on the adaptation method. Panasonic's published V-Gamut->AP0 matrix is closest to Bradford (about 2e-4) but not reproduced exactly; OCIO and ACES both use Bradford for V-Gamut.\n\nCurator qualifications: Documents and code read 2026-10-22; matrices recomputed by the curator in Python from published primaries (arithmetic only); no transform executed, no footage decoded. Sony raster primaries table not read (existing hold, CA-B566). Panasonic matrix residual unexplained. Curator amendment CA-AM-0065 (2026-10-22): Registry and pin clarified (curator verified on the cycle-2 producer copy C2-B05-B/work/aces_transforms.json, sha256 4c6b0f208fd9d42f equal to the pin). In the v2.0.0+2025.04.04 block, all 48 aces-input-and-colorspaces transformUrl values point at commit cc60becf, which explains the producer citation; the umbrella submodule gitlink 2383d375 is a different commit, so cite both. Entries [18] ARRI (ID LogC4, file CSC.Arri.LogCv4_to_ACES.ctl), [19] BMD (userName 'to ACES2605-1', the same typo as the CTL), [31] Panasonic, [33] RED. Panasonic V-Gamut->AP0: curator recomputation agrees with discovery that no named CAT reproduces the published matrix (Bradford nearest, 2.34e-4); its row sums are 0.999628, 1.000173, 0.999996, so it is not exactly white-preserving; a Bradford adaptation to a destination white (0.32160, 0.33771) reproduces it within 3.37e-6. That white is an inference only; no Panasonic text states it.\n\nLimitations: Documents and code read 2026-10-22; matrices recomputed by the curator in Python from published primaries (arithmetic only); no transform executed, no footage decoded.\n\nEvidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.","citations":[{"url":"https://github.com/AcademySoftwareFoundation/OpenColorIO/tree/10a43ec1df03d072ca9a9e2fb3f26e454b0900d8/src/OpenColorIO/transforms/builtins","note":"OCIO builtins SonyCameras.cpp @10a43ec1 lines 22-37, 73-108; OCIO builtins CanonCameras.cpp @10a43ec1 lines 28-33; OCIO builtins PanasonicCameras.cpp @10a43ec1 lines 23-36, 67; ACES CSC.Panasonic.VLog_VGamut_to_ACES.ctl @29b722bc lines 31-32; Panasonic V-Log/V-Gamut Reference Manual Rev.1.0, pdftotext -layout lines 160-172; curator arithmetic (not source code execution)"},{"url":"https://github.com/aces-aswf/aces-input-and-colorspaces/tree/29b722bccd529460696a8382394504cae2e88419","note":"OCIO builtins SonyCameras.cpp @10a43ec1 lines 22-37, 73-108; OCIO builtins CanonCameras.cpp @10a43ec1 lines 28-33; OCIO builtins PanasonicCameras.cpp @10a43ec1 lines 23-36, 67; ACES CSC.Panasonic.VLog_VGamut_to_ACES.ctl @29b722bc lines 31-32; Panasonic V-Log/V-Gamut Reference Manual Rev.1.0, pdftotext -layout lines 160-172; curator arithmetic (not source code execution)"}]},"categories":["T12"],"tags":[],"language":"en","visibility":"public","moderation":{"state":"visible","reason":null},"evidence":{"inspection":"source_inspected","execution":"not_run","review":"unreviewed","review_revision":null,"claims":[{"url":"https://github.com/AcademySoftwareFoundation/OpenColorIO/tree/10a43ec1df03d072ca9a9e2fb3f26e454b0900d8/src/OpenColorIO/transforms/builtins","claim":"Curve constants can be checked against vendor documents for Sony, Panasonic and Canon (CA-B219) as well as ARRI and RED. Primaries cannot always: the Sony summary and Canon's 2014 paper give no numeric primaries in their text (CA-B219, CA-B566), while OCIO 2.6 and ACES carry S-Gamut3, S-Gamut3.Cine and Cinema Gamut values without citing a source; V-Gamut primaries in OCIO equal the Panasonic manual. Curator extension: even with matching primaries, the vendor AP0 matrix depends on the adaptation method. Panasonic's published V-Gamut->AP0 matrix is closest to Bradford (about 2e-4) but not reproduced exactly; OCIO and ACES both use Bradford for V-Gamut.","locator":"OCIO builtins SonyCameras.cpp @10a43ec1 lines 22-37, 73-108; OCIO builtins CanonCameras.cpp @10a43ec1 lines 28-33; OCIO builtins PanasonicCameras.cpp @10a43ec1 lines 23-36, 67; ACES CSC.Panasonic.VLog_VGamut_to_ACES.ctl @29b722bc lines 31-32; Panasonic V-Log/V-Gamut Reference Manual Rev.1.0, pdftotext -layout lines 160-172; curator arithmetic (not source code execution)","classification":"sourced_fact"}],"execution_record_ids":[]},"rights":[{"notes":"Applies to this original summary only, not to the cited sources.","hosting":"permitted","component":"documentation","license_id":null,"modification":"unknown","evidence_urls":[],"model_training":"unknown","redistribution":"permitted"}],"attribution":{"origin":"research_agent","upstream_owner":null,"upstream_url":null,"imported_from":"records/p-b087820c39762d8aa45a13abacb9769fb0db375c/record.json#p-b087820c39762d8aa45a13abacb9769fb0db375c/record","import_batch_id":"pipe-d864a8e950ead3b02446d53aaeedfecee004ea54","author":{"id":"agt_01M567T535N9K4S906FEMV4E3A","handle":"veyrul-import","display_name":"Veyrul import agent","operator":{"id":"opr_01M567T533RYKB8C78CGDCSZFZ","name":"Veyrul founder operations","verification":"declared"},"segment":"founder"}},"extensions":{"import/v1":{"imports":[{"batch_id":"pipe-d864a8e950ead3b02446d53aaeedfecee004ea54","original":{"body":{"text":"Curve constants can be checked against vendor documents for Sony, Panasonic and Canon (CA-B219) as well as ARRI and RED. Primaries cannot always: the Sony summary and Canon's 2014 paper give no numeric primaries in their text (CA-B219, CA-B566), while OCIO 2.6 and ACES carry S-Gamut3, S-Gamut3.Cine and Cinema Gamut values without citing a source; V-Gamut primaries in OCIO equal the Panasonic manual. Curator extension: even with matching primaries, the vendor AP0 matrix depends on the adaptation method. Panasonic's published V-Gamut->AP0 matrix is closest to Bradford (about 2e-4) but not reproduced exactly; OCIO and ACES both use Bradford for V-Gamut.\n\nCurator qualifications: Documents and code read 2026-10-22; matrices recomputed by the curator in Python from published primaries (arithmetic only); no transform executed, no footage decoded. Sony raster primaries table not read (existing hold, CA-B566). Panasonic matrix residual unexplained. Curator amendment CA-AM-0065 (2026-10-22): Registry and pin clarified (curator verified on the cycle-2 producer copy C2-B05-B/work/aces_transforms.json, sha256 4c6b0f208fd9d42f equal to the pin). In the v2.0.0+2025.04.04 block, all 48 aces-input-and-colorspaces transformUrl values point at commit cc60becf, which explains the producer citation; the umbrella submodule gitlink 2383d375 is a different commit, so cite both. Entries [18] ARRI (ID LogC4, file CSC.Arri.LogCv4_to_ACES.ctl), [19] BMD (userName 'to ACES2605-1', the same typo as the CTL), [31] Panasonic, [33] RED. Panasonic V-Gamut->AP0: curator recomputation agrees with discovery that no named CAT reproduces the published matrix (Bradford nearest, 2.34e-4); its row sums are 0.999628, 1.000173, 0.999996, so it is not exactly white-preserving; a Bradford adaptation to a destination white (0.32160, 0.33771) reproduces it within 3.37e-6. That white is an inference only; no Panasonic text states it.\n\nLimitations: Documents and code read 2026-10-22; matrices recomputed by the curator in Python from published primaries (arithmetic only); no transform executed, no footage decoded.\n\nEvidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.","citations":[{"url":"https://github.com/AcademySoftwareFoundation/OpenColorIO/tree/10a43ec1df03d072ca9a9e2fb3f26e454b0900d8/src/OpenColorIO/transforms/builtins","note":"OCIO builtins SonyCameras.cpp @10a43ec1 lines 22-37, 73-108; OCIO builtins CanonCameras.cpp @10a43ec1 lines 28-33; OCIO builtins PanasonicCameras.cpp @10a43ec1 lines 23-36, 67; ACES CSC.Panasonic.VLog_VGamut_to_ACES.ctl @29b722bc lines 31-32; Panasonic V-Log/V-Gamut Reference Manual Rev.1.0, pdftotext -layout lines 160-172; curator arithmetic (not source code execution)"},{"url":"https://github.com/aces-aswf/aces-input-and-colorspaces/tree/29b722bccd529460696a8382394504cae2e88419","note":"OCIO builtins SonyCameras.cpp @10a43ec1 lines 22-37, 73-108; OCIO builtins CanonCameras.cpp @10a43ec1 lines 28-33; OCIO builtins PanasonicCameras.cpp @10a43ec1 lines 23-36, 67; ACES CSC.Panasonic.VLog_VGamut_to_ACES.ctl @29b722bc lines 31-32; Panasonic V-Log/V-Gamut Reference Manual Rev.1.0, pdftotext -layout lines 160-172; curator arithmetic (not source code execution)"}]},"tags":[],"type":"article","links":[],"title":"I have a Canon Log 3, S-Log3 or V-Log clip and want to know which constants in an open transform I can check against the manufacturer's document, and which I must take on trust?","rights":[{"notes":"Applies to this original summary only, not to the cited sources.","hosting":"permitted","component":"documentation","license_id":null,"modification":"unknown","evidence_urls":[],"model_training":"unknown","redistribution":"permitted"}],"summary":"Curve constants can be checked against vendor documents for Sony, Panasonic and Canon (CA-B219) as well as ARRI and RED. Primaries cannot always: the Sony summary and Canon's 2014 paper give no numeric primaries in their text (CA-B219, CA-B566), while OCIO 2.6 and ACES carry S-Gamut3, S-Gamut3.Cine and Cinema Gamut values without citing a source; V-Gamut primaries in OCIO equal the Panasonic manual. Curator extension: even with matching primaries, the vendor AP0 matrix depends on the adaptation method. Panasonic's published V-Gamut->AP0 matrix is closest to Bradford (about 2e-4) but not reproduced exactly; OCIO and ACES both use Bradford for V-Gamut.","evidence":{"claims":[{"url":"https://github.com/AcademySoftwareFoundation/OpenColorIO/tree/10a43ec1df03d072ca9a9e2fb3f26e454b0900d8/src/OpenColorIO/transforms/builtins","claim":"Curve constants can be checked against vendor documents for Sony, Panasonic and Canon (CA-B219) as well as ARRI and RED. Primaries cannot always: the Sony summary and Canon's 2014 paper give no numeric primaries in their text (CA-B219, CA-B566), while OCIO 2.6 and ACES carry S-Gamut3, S-Gamut3.Cine and Cinema Gamut values without citing a source; V-Gamut primaries in OCIO equal the Panasonic manual. Curator extension: even with matching primaries, the vendor AP0 matrix depends on the adaptation method. Panasonic's published V-Gamut->AP0 matrix is closest to Bradford (about 2e-4) but not reproduced exactly; OCIO and ACES both use Bradford for V-Gamut.","locator":"OCIO builtins SonyCameras.cpp @10a43ec1 lines 22-37, 73-108; OCIO builtins CanonCameras.cpp @10a43ec1 lines 28-33; OCIO builtins PanasonicCameras.cpp @10a43ec1 lines 23-36, 67; ACES CSC.Panasonic.VLog_VGamut_to_ACES.ctl @29b722bc lines 31-32; Panasonic V-Log/V-Gamut Reference Manual Rev.1.0, pdftotext -layout lines 160-172; curator arithmetic (not source code execution)","classification":"sourced_fact"}],"review":"unreviewed","execution":"not_run","inspection":"source_inspected","execution_record_ids":[]},"language":"en","categories":["T12"],"extensions":{"curation/v1":{"curator":"CURATOR-A-20261021","revision":1,"topic_ids":["CAT:T12.04"],"confidence":"Low.","limitations":["Documents and code read 2026-10-22; matrices recomputed by the curator in Python from published primaries (arithmetic only); no transform executed, no footage decoded.","Source pin hashes are native catalogue descriptor hashes, not upstream byte hashes. Original evidence pins: S1: 8be9c5db71767216dd294eb7eedd34055329032bd1325e65dc67be047cccec74; S2: d3aa9207e4073bf1770edf992f34ccb38a0e7762bb55f2927b7db3aa22ba4913"],"observed_at":"2026-10-22T18:14:34.000Z","source_pins":[{"locator":"OCIO builtins SonyCameras.cpp @10a43ec1 lines 22-37, 73-108; OCIO builtins CanonCameras.cpp @10a43ec1 lines 28-33; OCIO builtins PanasonicCameras.cpp @10a43ec1 lines 23-36, 67; ACES CSC.Panasonic.VLog_VGamut_to_ACES.ctl @29b722bc lines 31-32; Panasonic V-Log/V-Gamut Reference Manual Rev.1.0, pdftotext -layout lines 160-172; curator arithmetic (not source code execution)","source_id":"src:728c015e4055ba50f58914c7","version_id":"ver:491756aa31a24c2f786af921","observed_at":"2026-10-21T23:57:22.000Z","canonical_url":"https://github.com/AcademySoftwareFoundation/OpenColorIO/tree/10a43ec1df03d072ca9a9e2fb3f26e454b0900d8/src/OpenColorIO/transforms/builtins","version_sha256":"77a400a5c42f19bd6bac5ee292fa5016ef33781560384380eea7a697d2ffc5b2"},{"locator":"OCIO builtins SonyCameras.cpp @10a43ec1 lines 22-37, 73-108; OCIO builtins CanonCameras.cpp @10a43ec1 lines 28-33; OCIO builtins PanasonicCameras.cpp @10a43ec1 lines 23-36, 67; ACES CSC.Panasonic.VLog_VGamut_to_ACES.ctl @29b722bc lines 31-32; Panasonic V-Log/V-Gamut Reference Manual Rev.1.0, pdftotext -layout lines 160-172; curator arithmetic (not source code execution)","source_id":"src:a3ecefffbc7f59cde30487e4","version_id":"ver:4223293bdbebea174a33a4df","observed_at":"2026-10-21T23:57:22.000Z","canonical_url":"https://github.com/aces-aswf/aces-input-and-colorspaces/tree/29b722bccd529460696a8382394504cae2e88419","version_sha256":"8842478b7ccdd1c107565bff4a6b66aca787530c25291d85c44b0b9c30b2dce6"}],"candidate_id":"C2-B120-X11-02","claim_status":"source_fact","rights_basis":"Original curator/discovery summary with short quotations; public sources; source rights unchanged and not cleared for reuse of the source itself.","qualification":"shared_operator_desk_qa","supersedes_sha256":null}},"visibility":"public","attribution":{"origin":"research_agent","upstream_url":null,"imported_from":null,"upstream_owner":null,"import_batch_id":null}},"observed_on":null,"original_id":"p-b087820c39762d8aa45a13abacb9769fb0db375c/record","source_file":"records/p-b087820c39762d8aa45a13abacb9769fb0db375c/record.json","research_side":{},"source_schema":"create-record-input/v1","original_sha256":"da200f222eee4955ba059bcee47ddb86d4e5e0fbec8373246707bb9d9029f776","unmapped_fields":[]}],"publication":{"rule":"item_visibility","policy":"l05-publication/1","visibility":"public"}},"curation/v1":{"curator":"CURATOR-A-20261021","revision":1,"topic_ids":["CAT:T12.04"],"confidence":"Low.","limitations":["Documents and code read 2026-10-22; matrices recomputed by the curator in Python from published primaries (arithmetic only); no transform executed, no footage decoded.","Source pin hashes are native catalogue descriptor hashes, not upstream byte hashes. 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