Sony's logarithmic gamma curve family (S-Log2, S-Log3) for maximum dynamic range capture.
Technical Details
S-Log operates with a base ISO of 3200 (S-Log2) or 800 (S-Log3) and utilizes the full 10-bit bandwidth of the sensor. S-Log2 uses a gamma curve of 0.432, while S-Log3 works with 0.420 and is closer to the Cineon curve. The profile intentionally produces flat, desaturated images with 18% gray at IRE 32.9 (S-Log2) or IRE 41.3 (S-Log3). The color temperature is set to 3200K by default to ensure maximum sensor performance.
Three main variants exist: S-Log, S-Log2, and S-Log3, with the latter introduced in 2014 and offering improved shadow detail. S-Gamut further expands the color space beyond Rec.709, capturing almost the entire visible spectral range.
History & Development
Sony introduced S-Log in 2012 with the F65 CineAlta camera, in response to ARRI's Log-C and RED's RedLogFilm. S-Log2 followed in 2013 with the FS700, while S-Log3 debuted in 2014 with the FX1000. The development was based on Kodak's Cineon standard from the 1990s, which already used logarithmic encoding for film scans.
In 2016, Sony integrated S-Log into consumer cameras like the A7S II, making log recording accessible to the prosumer market. Current iterations support 16-bit recording in conjunction with external recorders.
Practical Use in Film
Christopher Nolan's "Dunkirk" (2017) utilized S-Log3 for IMAX sequences to achieve maximum flexibility in color grading. "Blade Runner 2049" used S-Log2 for complex VFX integration across different lighting situations.
The standard workflow requires LUTs (Look-Up Tables) or manual color correction in DaVinci Resolve, Avid, or Adobe Premiere. S-Log footage absolutely requires post-production – direct screening results in unusable, flat images. The extended gradability allows for extreme corrections without artifacts, but demands precise exposure, as underexposure leads to noise in the shadows.
Comparison & Alternatives
Unlike ARRI's Log-C (800 ASA base ISO), S-Log operates with higher native sensitivity, offering advantages in low-light situations. RED's RedLogFilm provides similar dynamic range but requires proprietary R3D codecs.
Canon C-Log and Panasonic's V-Log offer comparable functionality, with V-Log being closer to S-Log3. Blackmagic Film and ProRes RAW bypass log encoding through direct RAW recording but require significantly more storage space. S-Log remains the standard for Sony-based productions, while cross-camera workflows often use ACES (Academy Color Encoding System) as a common denominator.