Sony FX3 and FX6 S-Log3 Footage to Rec.709: The LUT and Grading Workflow

Why Sony Footage Looks Different Than Canon or RED

The Sony FX3 and FX6 are popular cinema cameras for indie productions and content creators. They record S-Log3, Sony's logarithmic profile that captures roughly 14 stops of dynamic range. The downside: the footage looks gray, low-contrast, and lifeless until graded.

Each manufacturer has their own LOG profile (Sony S-Log3, Canon C-Log, RED Log3G10, ARRI LogC). They look similar at first glance but encode shadow and highlight information slightly differently. Treating S-Log3 like LogC gives a different result than treating it correctly.

This post covers the S-Log3 workflow specifically: which LUT to use, how to handle the SGamut3.Cine vs Rec.709 color space mismatch, and the highlight rolloff that distinguishes Sony footage from competitors. Our video compressor handles encoding after grading.

For broader LOG-to-Rec.709 patterns, see DJI D-Log to Rec.709.

What S-Log3 Actually Captures

S-Log3 is a logarithmic transfer function paired with a wide gamut color space (SGamut3.Cine):

• 14+ stops dynamic range
• 18% gray at IRE 41 (vs IRE 38 in S-Log2)
• Highlights extend to IRE 89 (vs IRE 64 in S-Log2)
• Wide color gamut (SGamut3.Cine, between Rec.709 and Rec.2020)

The "flat look" is because the camera is recording a much wider tonal range than your monitor can display. To see it correctly, you apply a LUT or grade that compresses 14 stops into the monitor's 7-9 stops.

Sony's Official LUTs

Sony publishes free LUTs for converting S-Log3 to standard color spaces. Download from Sony's website:

• S-Log3-S-Gamut3.Cine_to_LC-709.cube (709 LUT)
• S-Log3-S-Gamut3_to_Rec709.cube (alternate 709)
• S-Log3-S-Gamut3.Cine_to_LC-709typeA.cube (cinematic 709 with stronger contrast)
• S-Log3-S-Gamut3.Cine_to_BT.2020.cube (HDR delivery)

Match the LUT to your delivery target:

The "typeA" variants are cinematic. The base "709" variants are more neutral and broadcast-safe.

Applying LUTs in DaVinci Resolve

For non-ACES workflow:

1. Import S-Log3 footage
2. Color page > 3D LUT > Sony LUT (e.g., LC-709typeA)
3. Apply to clip
4. Tweak before/after the LUT for refinements

For ACES workflow (the cleaner option):

1. Project Settings > Color Management > ACEScct
2. Set IDT per clip: Sony S-Log3 SGamut3.Cine
3. Set ODT: Rec.709
4. Grade in ACES space
5. The LUT is unnecessary; ACES handles the conversion

For background on ACES workflow, see ACES Color Pipeline.

Manual Grading Without LUT

For full control:

1. Set Lift to lift shadows (S-Log3 has crushed shadows compared to S-Log2)
2. Set Gain to compress highlights (pull down highlights)
3. Set Saturation to ~125% (Sony LOG comes saturated; LUT compresses it)
4. Apply Tetra (3-way correction) for skin tone refinement
5. Final contrast bump via Curves

This produces a more nuanced result than a single LUT but takes longer per clip.

Common Sony Highlight Issues

S-Log3 retains highlights well in the file, but the LUTs can crush them:

Issue: Sky clips to flat blue/cyan.
Fix: Apply Curves before the LUT, gently pull the highlight rolloff. Or use the BT.2020 LUT which has more highlight headroom.

Issue: White shirts go to 100% white (clipped).
Fix: Reduce exposure -0.3 stops before the LUT. The LUT then has room to display the highlight detail.

Issue: Magenta cast in highlights on caucasian skin.
Fix: Apply hue rotation -5° in the highlights only. Use Resolve's Qualifier to isolate face regions.

For HDR delivery via the BT.2020 LUT, the highlight handling is much better. See HDR10 vs Dolby Vision Conversion for HDR specifics.

Skin Tone Tuning

Sony skin tones come out slightly green-cyan compared to Canon's warmer rendition. Two adjustments:

Adjustment 1: Hue rotation

Use Resolve's Color Wheels:

• Lift wheel: nudge slightly toward red/yellow
• Gain wheel: small nudge toward yellow
• This adds warmth across the image

Adjustment 2: Skin qualifier

Use the Qualifier to select skin tones, then adjust just those:

• Saturation: +5%
• Hue rotation: +3° (warmer)
• Lift slightly toward yellow

Skin qualifier is the surgical option. Adjust hue tones across the image is the broader option. Most colorists use both: broad correction first, then qualified adjustment for fine work.

Codec Considerations

Sony FX3 and FX6 record:

For most workflows: XAVC S-I 4K. The 4:2:2 color sampling holds up better through grading than 4:2:0.

For the ProRes intermediate workflow, see Apple ProRes Windows Workflow.

Editing in Premiere

Premiere's Lumetri Color panel handles S-Log3:

1. Effects > Color > Lumetri Color
2. Basic Correction > Input LUT > load Sony LUT
3. Adjust further with Lumetri's color tools

Premiere's color management is weaker than DaVinci's, but the Lumetri panel covers most needs. For ACES-grade work, send to DaVinci or Final Cut Pro.

File Sizes

For 10 minutes of FX3 footage:

For projects without external recorders, XAVC S-I is the production sweet spot.

Common Issues

Footage looks blue/cool: white balance was off at recording. Use Resolve's Color Wheels to add yellow/red. For systematic correction, set white balance using the gray card chart.

Color shift after FFmpeg conversion: missing color metadata. Force Rec.709 output:

ffmpeg -i input.mov \
  -c:v libx264 -preset slow -crf 18 \
  -color_primaries bt709 -color_trc bt709 -colorspace bt709 \
  -pix_fmt yuv420p \
  -movflags +faststart \
  output.mp4

Lift wheel doesn't add expected warmth: Sony LOG is more saturated than expected. The Lift adjustments are subtle on saturated source. Use Curves instead for finer shadow control.

S-Log3 footage has banding: 8-bit deliverable from 10-bit source. Output 10-bit (HEVC or H.265) for delivery if banding is visible.

For underlying codec considerations, see HEVC to H.264 for Premiere.

Frequently Asked Questions

Should I shoot S-Log3 or S-Cinetone?

S-Cinetone is a "ready to use" profile that needs little grading. Faster turnaround. S-Log3 needs grading but provides much more flexibility. For client work with quick turnaround: S-Cinetone. For productions with grading time: S-Log3.

Can I use S-Log2 LUTs on S-Log3 footage?

No. S-Log2 and S-Log3 have different transfer curves. The result will look wrong. Use S-Log3 LUTs only.

What about the Sony FX9 and Venice?

Same workflow. The cameras record S-Log3 in higher bit-depth (Venice 16-bit RAW). The grading principles are identical, but Venice's color resolution gives more grading headroom.

Is the FX3 acceptable for theatrical work?

For sub-2K theatrical: yes, acceptable. For 4K theatrical: borderline. Theatrical productions typically use FX9 or Venice for the bigger sensor and color resolution.

How do I convert FX6 internal ProRes to a deliverable?

ProRes 422 HQ from internal recording is editorial-grade. Edit in Resolve, grade with S-Log3 IDT or LUT, deliver to H.264/HEVC. Our MP4 converter handles the final encode.

Does the FX6 internal RAW recording use S-Log3?

The FX6 with the SDI RAW output records X-OCN RAW (Sony's RAW format). The grading workflow is similar to S-Log3 but at higher bit depth. Use the X-OCN to Rec.709 LUT or ACES IDT.

Related Reading

• DJI D-Log to Rec.709
• ACES Color Pipeline in DaVinci Resolve
• HDR10 vs Dolby Vision Conversion

Bottom Line

For Sony FX3/FX6 S-Log3 to Rec.709: download Sony's LC-709typeA LUT for cinematic work or LC-709 for broadcast, apply in DaVinci Resolve or Premiere Lumetri, tweak skin tones with hue rotation, output 10-bit if banding is visible. ACES workflow gives even cleaner result for HDR-aware projects. Our video compressor handles the final encode.