Fujifilm GFX100S II Medium Format Photography Camera

Fujifilm's first log curve, introduced with the X-T3 generation in 2018 and paired with F-Gamut, which Fujifilm defines as ITU-R BT.2020. It places 18% gray at 0.4593, the highest of any curve in this base, leaving only 5.3 stops of encoding above mid gray. That is the trade behind its 13 stops of curve latitude: more of the code range is spent below middle gray than above it, so shadows are well protected and highlight room runs out sooner than on F-Log2.

Introduced with F-Log for the X-series and later the GFX line. Fujifilm defines it as ITU-R BT.2020 outright — the F-Log data sheet states the compliance — so its primaries are identical to the Rec.2020 record in this base and every one of them is realisable. Being a standard rather than a proprietary space simplifies the grade: no manufacturer-specific gamut transform is required, and only the F-Log curve has to be linearized.

• Fujifilm F-Log Data SheetPDF
• FUJIFILM Film Simulation LUTsWeb ↗

Introduced with the X-H2 and X-H2S generation in 2022 as a higher-latitude alternative to F-Log. It moves 18% gray down from F-Log's 0.4593 to 0.3910, and that shift is what buys the extra range: headroom rises from 5.3 stops to 8.3. The F-Log2 C variant on the GFX ETERNA uses this identical transfer function and differs only in gamut, so the two share a single linearization step in post.

Introduced with F-Log for the X-series and later the GFX line. Fujifilm defines it as ITU-R BT.2020 outright — the F-Log data sheet states the compliance — so its primaries are identical to the Rec.2020 record in this base and every one of them is realisable. Being a standard rather than a proprietary space simplifies the grade: no manufacturer-specific gamut transform is required, and only the F-Log curve has to be linearized.

• Fujifilm F-Log2 C Data SheetPDF
• Fujifilm F-Log2 Data SheetPDF
• FUJIFILM Film Simulation LUTsWeb ↗

Hybrid Log-Gamma, developed jointly by the BBC and NHK and standardized in ITU-R BT.2100. It follows a conventional gamma curve through shadows and midtones and switches to logarithmic encoding only in the highlights, which is where the name comes from. That hybrid shape is what lets a single signal render acceptably on both SDR and HDR displays without a separate SDR master. It is scene-referred and display-independent, unlike PQ, which makes it the practical choice for live broadcast where the viewer's display cannot be assumed.

Defined in ITU-R BT.2020 in 2012 for ultra-high-definition television; BT.2100 later reused the same primaries for HDR. All three primaries sit on the spectral locus — they are monochromatic — which makes it the widest gamut definable without imaginary coordinates, covering 1.89 times the area of Rec.709. It is a delivery container rather than a capture space. No current display reproduces it in full, so HDR work is typically monitored on a P3 subset and delivered inside a 2020 container.

• ITU-R Recommendation BT.2100 (HDR Television Parameter Values — HLG/PQ)Web ↗