S-Log2 to Rec.709 needs one thing to go right: a conversion LUT built for S-Log2 and S-Gamut, applied before any look. The most common mistake is using an S-Log3 LUT because that is what most Sony guides are about. It looks close, but skin and shadows come out wrong.
What is S-Log2, and how is it different from S-Log3?
S-Log2 is the older of Sony's two log curves, and many Alpha bodies record both. On cameras such as the a6400 and a7 III, picture profile PP7 is S-Log2. PP8 and PP9 are S-Log3. Older bodies may only have S-Log2.
| S-Log2 | S-Log3 | |
|---|---|---|
| Middle grey (18%) sits at, per Sony's technical summary | About 32% IRE | About 41% IRE |
| Usual gamut on Alpha bodies | S-Gamut | S-Gamut3.Cine or S-Gamut3 |
| Picture profile on many Alpha bodies | PP7 | PP8, PP9 |
| Shadows | A little more contrast, less lifted | Flatter, more lifted |
| Conversion LUT | An S-Log2 file | An S-Log3 file |
Because the curves differ, the conversions are not interchangeable. An S-Log3 LUT on S-Log2 footage reads the shadows and midtones in the wrong place and the result comes out too dark and too contrasty. Log footage explains the general idea; S-Log3 to Rec.709 covers the newer curve.
How do you check which log your clips are?
Before you pick a LUT:
- Open the camera's picture profile menu and note the profile you used, and its Gamma and Color Mode settings.
- Gamma S-Log2 means this post. Gamma S-Log3 means the S-Log3 post.
- Note the Color Mode too. S-Gamut is the usual partner for S-Log2; if you changed it, find a LUT for that pair.
If the shoot is already over and you are not sure, pick a clip with a grey or white surface and try both conversions. The wrong one usually shows straight away in the shadows and skin.
Which LUT converts S-Log2 to Rec.709?
Use a conversion that names S-Log2 and the gamut you recorded:
- Sony's own conversions. Sony's LUT pack for its cinema cameras includes S-Log2/S-Gamut versions of its LC-709 and LC-709TypeA conversions. DaVinci Resolve also installs Sony's classic conversion LUTs in its Sony LUT folder. Look for files that start with
SLog2SGamut. - A colour space transform. DaVinci Resolve's Color Space Transform effect can convert from Sony S-Gamut and Sony S-Log2 to Rec.709 without a LUT file.
- Third-party conversions. Some colourists sell S-Log2 conversions with a gentler shadow roll-off. Check that the file says S-Log2 and S-Gamut before you buy.
LC-709TypeA is a common default because it holds skin well. LC-709 is flatter and leaves room for a grade. Sony LUTs explains how the LC-709 family differs.
How do you convert one S-Log2 clip?
| Editor | Where the conversion goes |
|---|---|
| DaVinci Resolve | A LUT or a Color Space Transform on the first node |
| Premiere Pro | Lumetri Color, Basic Correction, Input LUT |
| Final Cut Pro | A Custom LUT effect on the clip |
| ffmpeg | lut3d=file=slog2_to_709.cube |
Correct exposure after the conversion, not before. Many S-Log2 clips are shot a little bright on purpose to keep noise out of the shadows, so expect to bring some of them down once they are in Rec.709. A creative look comes last. LUT stacking covers why that order matters.
How do you convert a whole card of S-Log2?
A card is rarely one clip. It is often dozens, shot across a day in changing light, and they all need the same conversion. In an editor that means a project, a timeline, the grade copied to every clip, and a render queue. DaVinci Resolve LUTs and colour grading in Premiere Pro walk through that route.
It works, but it is an edit's worth of setup for a job that has no edit in it. The other route is a batch tool that applies one LUT to the whole folder.
BatchTone is a Mac app built for that job:
- Drop the folder of clips in, with any stills from the same shoot.
- Import your S-Log2 conversion
.cubeonce. BatchTone ships no LUTs, so you use Sony's file or the one you trust. - Check the preview frame from each clip with the conversion applied, so a clip that converts badly shows up before the export, not after.
- Lower the strength on the clips that need less; the rest stay at the global setting, so you only touch the few that need it.
- Export H.264 MP4 to a folder you choose. Audio is copied untouched, and the originals are never written to, so a wrong choice costs you nothing but a re-export.
Sony's XAVC S files go straight in, since the ffmpeg build inside BatchTone decodes H.264 and HEVC, 10-bit included. It runs on macOS 12 or later on Apple Silicon. The seven-day trial has everything unlocked, so you can test it on your own S-Log2 card before you pay; after that it is one in-app purchase, not a subscription.
Download BatchTone free on the Mac App Store
Common questions
Can I use an S-Log3 LUT on S-Log2 footage?
It will look wrong. The two curves place middle grey at different levels, so the S-Log3 conversion makes S-Log2 footage too dark and too contrasty. Use a conversion made for S-Log2.
Which picture profile is S-Log2 on Sony cameras?
On many Alpha bodies, such as the a6400 and a7 III, PP7 is S-Log2 with S-Gamut. Check the Gamma line inside the profile, since any profile can be edited.
Is S-Log2 better than S-Log3 in 8-bit?
Many shooters prefer S-Log2 for 8-bit recording because it is less flat, so a strong grade stretches the data less. If your camera records 10-bit, S-Log3 is the usual choice. 8-bit vs 10-bit covers why bit depth matters for log.
Does Sony make a LUT for S-Log2?
Yes. Sony's conversion LUTs include S-Log2/S-Gamut versions of LC-709 and LC-709TypeA, and Resolve installs Sony's classic set. Avoid re-hosted copies with no file names you can check.
Should I convert S-Log2 before editing?
Convert the whole card first when the client wants files or the clips go straight out. Convert inside the edit when only a few clips make the cut.