Batch convert S-Log3 to Rec.709 for hundreds of clips
Converting one S-Log3 clip to Rec.709 is easy. Converting a whole wedding or a week of travel footage is where the hours go, because every clip was shot a little differently. This guide shows how to do the whole shoot in one pass and what a single LUT on every clip leaves undone.
Last checked 2026-10-25, against Basecut 4.1.1.
Where a step names Basecut, it is our product, so judge that part on your own footage. The order of the correction is the same in any tool.
Why one LUT on every clip is not enough
A conversion LUT changes the S-Log3 curve and colors into Rec.709. It assumes the clip was exposed and white balanced the way the LUT expects. On a real shoot that is rarely true for every clip: the ceremony was a stop under, the reception was under tungsten, the B camera was set a little warmer.
So a batch conversion has three parts, in this order. Convert the log to Rec.709. Correct each clip's white balance and exposure. Match the cameras to each other. The first part is one setting. The second and third are what take the time on a few hundred clips, and they are measurable, which is why they can be automated.
Your options
| Approach | Good for | Where it falls short |
|---|---|---|
| One conversion LUT on every clip in your editor | Fast, and fine for a shoot with steady light and careful exposure. | Converts the curve only. Every clip keeps its own white balance and exposure error, and cameras still do not match. |
| Color-managed project in DaVinci Resolve | Sets the input color space for many clips at once, with a clean transform. | Still a transform only. White balance, exposure and the camera match are a second pass, clip by clip or shot by shot. |
| Basecut, then your editor | The whole shoot detected, converted, corrected per clip and matched across cameras in one pass, then sent to Resolve, Premiere Pro or Final Cut Pro. | Our product. It is a correction, not a creative grade, and outside Resolve Studio you apply the .cube files yourself. |
Step by step
1. Import the whole shoot, every camera together
Point Basecut at the card dump or the folder. You do not need to sort the clips by camera first: Basecut detects the log profile clip by clip, so Sony S-Log3 from the main camera and a different log format from a second body each get their own conversion. Basecut reads the files where they are and never changes the originals.
2. Check the detected profile on a few clips
Open the Color tab and look at the Log profile for a clip from each camera. If a clip was detected wrong or left as unknown, set it to Sony S-Log3 in the Log profile menu. Basecut's S-Log3 conversion is built for S-Gamut3.Cine; if you shot plain S-Gamut3, check skin tones and strong colors on a few clips.
3. Let the per-clip correction run
After the conversion to Rec.709, Basecut sets white balance and exposure for each clip on its own, so a clip shot a stop under and a clip shot in shade both land in a normal range. This is a correction, not a creative look: it aims for accurate color and leaves the grade to you.
4. Match the cameras
Click Color-match clips to bring every clip in the shoot to a shared look, so the A camera, the B camera and the phone cut together without a jump in color.
5. Take the result to your editor
In DaVinci Resolve Studio, Send to Resolve applies the correction to every clip for you. In free Resolve, Premiere Pro and Final Cut Pro, each clip comes with a .cube file that carries the same correction, ready to apply. Export, Graded clips and LUTs copies the keepers and their .cube files to a folder.
6. Or render corrected files
If your editor cannot load a LUT, or you just want Rec.709 files, Export, Render video writes the correction into new files for your hero and keeper clips, as ProRes, H.265 or H.264. Your S-Log3 originals stay untouched.
What to check before you deliver
- Skin tones on a few clips from each camera, especially under mixed light.
- Clips that were badly over or under exposed. A safe correction may still leave them flatter than the rest.
- In Final Cut Pro, set the clip's Camera LUT to None before you add the .cube with the Custom LUT effect, so you do not convert twice.
- In Premiere Pro and free Resolve, apply each clip's own .cube, not one cube to every clip.
Doing it by hand in one editor? See S-Log3 to Rec.709 in Final Cut Pro, S-Log3 to Rec.709 in Premiere Pro and the full S-Log3 color correction workflow.
More guides
Questions people ask
How do I convert hundreds of S-Log3 clips to Rec.709 at once?
In any editor you can apply one conversion LUT to many clips, but that only converts the curve: every clip keeps its own white balance and exposure problems. Basecut detects S-Log3 per clip, converts it to Rec.709, corrects white balance and exposure for each clip, and matches the cameras across the whole shoot in one pass.
Is one LUT on every clip good enough?
For a perfectly exposed, perfectly balanced shoot, close. For a real shoot, no. A conversion LUT assumes the clip was exposed and balanced the way the LUT expects. Clips shot over or under, or under mixed light, need their own correction before or after the LUT, which is the part that takes the time on a few hundred clips.
Does Basecut apply a look or a grade?
No. It corrects: log to Rec.709, white balance, exposure and a match across cameras. Creative looks are a separate layer you choose yourself.
What if my second camera is not a Sony?
Basecut detects the log profile per clip, including Apple Log, Canon C-Log2 and C-Log3, Panasonic V-Log, DJI D-Log, Fujifilm F-Log2 and others, so each camera gets its own conversion before the cameras are matched.
Does it change my original S-Log3 files?
No. The correction travels as a .cube file per clip, is applied inside Resolve Studio, or is written into new files when you render. The originals are never modified.
Does it upload my footage to do the color?
No. The conversion, correction and camera match are computed on your computer.
Correct the whole shoot in one pass
Basecut detects S-Log3 per clip, converts it to Rec.709, fixes white balance and exposure, and matches your cameras. Mac and Windows. 14-day free trial, 5 free exports, no card.
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