Canon Log 3 color grading in DaVinci Resolve
Canon Log 3 converts to Rec.709 with a single Color Space Transform. Getting it clean comes down to matching the gamut the camera recorded, exposing middle grey where Canon puts it, and correcting before the conversion.
How do you color grade Canon Log 3 in DaVinci Resolve?
Correct exposure and white balance on a first node, then add a Color Space Transform set to Input Color Space Canon Cinema Gamut, Input Gamma Canon Log 3, Output Color Space Rec.709 and Output Gamma Gamma 2.4, with tone mapping on. Contrast, skin and the creative look all go after that node.
That is the whole recipe. The rest of this guide is about the details that decide whether it works: which gamut and curve the camera wrote, where middle grey should sit, and the problems C-Log3 footage brings.
Canon Log, Canon Log 2 and Canon Log 3: what each one is
Canon has three log curves, and they are not interchangeable. The figures below are from Canon's white paper on its log gamma curves.
| Curve | 18% grey | 90% white | What it is for |
|---|---|---|---|
| Canon Log | 34.3% | 60.0% | The original curve, built for simple grading |
| Canon Log 2 | 39.8% | 56.2% | The widest range; assumes the footage will be graded |
| Canon Log 3 | 34.3% | 56.4% | More range than Canon Log, with the same easy handling |
The gamut is a separate setting. Most log shooting uses Cinema Gamut, but many Canon bodies also offer BT.709 and BT.2020. Resolve asks for the curve and the gamut separately, so check both on the camera. Choosing Canon Log 2 for Canon Log 3 footage shifts the whole tonal range; choosing the wrong gamut leaves contrast looking right while hue and saturation drift.
Step 1: Expose Canon Log 3 for 34.3% middle grey
Canon's white paper places 18% middle grey at 34.3% and 90% white at 56.4% for Canon Log 3. Put a grey card in the frame, open the waveform, and land it at about 34. That is "correct" exposure for the curve.
Many shooters rate log brighter than the specification to keep shadows clean. That is a valid choice as long as the highlights are not clipping. Whatever you choose, be consistent across the shoot, and pull the exposure back to normal in the grade before the conversion.
- Base ISO. Log raises the minimum ISO. Canon's paper gives ISO 800 as the setting where Canon Log 2 and Canon Log 3 reach their full range on the EOS C300 Mark II; check the manual for your body.
- 10-bit. Log spreads tonal values across the file. Record 10-bit wherever the camera offers it, or skies and soft walls band once the image is stretched.
- View assist. A view-assist display only changes the monitor, not the recording. Judge exposure on the waveform, not on how the assisted picture looks.
Step 2: Convert with a Color Space Transform
On the Color page, add a serial node after your correction node (Alt+S on Windows, Option+S on Mac), drag Color Space Transform from the Effects library onto it, and set:
- Input Color Space: Canon Cinema Gamut, or the BT.709 or BT.2020 gamut if that is what the camera was set to
- Input Gamma: Canon Log 3 (or Canon Log 2 or Canon Log, to match the camera)
- Output Color Space: Rec.709
- Output Gamma: Gamma 2.4 (see the Rec.709 guide for when 2.2 makes sense)
- Tone Mapping Method: DaVinci or Luminance Mapping, so the extra stops roll off instead of clipping
- Gamut Mapping Method: Saturation Compression, which helps with neon, stage lights and saturated LEDs
If you prefer project-wide colour management, go to File > Project Settings > Color Management, set Color science to DaVinci YRGB Color Managed and the output to Rec.709 Gamma 2.4. Then right-click the Canon clips on the Color page and set their Input Color Space to the matching Canon Cinema Gamut / Canon Log 3 entry. On multi-camera projects this is the cleaner route, and it is covered in the general LOG workflow.
Should you use a Canon LUT instead?
A conversion LUT is a fine starting point, but it is a fixed table: it assumes the shot was exposed to the specification, and it clips anything outside the range it was built for. If you rated the footage bright, a LUT looks bright until you correct upstream of it. The Color Space Transform does the same conversion mathematically and lets you choose how highlights roll off. If you do use a LUT, put it on its own node after the correction node. The LUT guide covers the trade-off in more depth.
Step 3: Correct before the conversion
Exposure and white balance belong on the node before the transform, while the image is still log-encoded. In log, the Offset wheel behaves much like an exposure change, moving the whole signal up or down without bending the curve, so it is the cleanest way to normalise a shot you rated bright. Use Temp and Tint on the same node for white balance.
After the transform, add a node for contrast, then one for secondaries, then the look. Correct, convert, shape, isolate, style: the same order as every log format.
Step 4: Fix the problems Canon Log 3 tends to show
- Noisy shadows. Usually the result of exposing at or below the 34.3% target in a dim scene. Lift less, accept slightly deeper blacks, or use temporal noise reduction, which needs Resolve Studio (see free vs Studio).
- Dark, heavy image after the transform. The footage was underexposed, or it was judged through view assist. Raise it with Offset on the node before the transform.
- Clipped saturated colours. Turn on gamut mapping in the transform, then use a Hue vs Sat curve on the offending colour.
- Banding in skies. Almost always 8-bit recording. Light grain can hide it, but it cannot be fully fixed in the grade.
Common Canon Log 3 mistakes
- Setting the transform to Canon Log 2 when the camera recorded Canon Log 3, or the reverse.
- Leaving the input on Cinema Gamut when the camera was set to BT.709 or BT.2020.
- Putting a creative LUT built for Rec.709 directly on unconverted log footage.
- Rating the footage bright on set, then fixing exposure after the conversion.
- Stacking a conversion LUT and a Color Space Transform, converting the image twice.
A proper conversion and skin tone pass is part of every finished edit I deliver. See YouTube video editing, or compare with the Sony S-Log3 workflow, which follows the same shape.
FAQ
What Color Space Transform settings does Canon Log 3 need?
Input Color Space Canon Cinema Gamut, Input Gamma Canon Log 3, Output Color Space Rec.709 and Output Gamma 2.4, with tone mapping on. If the camera was set to a BT.709 or BT.2020 gamut instead of Cinema Gamut, use that as the Input Color Space.
What IRE should Canon Log 3 be exposed at?
Canon's white paper on its log curves places 18% middle grey at 34.3% and 90% white at 56.4% for Canon Log 3. Many shooters expose somewhat brighter to keep shadows clean, then bring exposure back down before the conversion.
Is Canon Log 2 better than Canon Log 3?
Canon Log 2 holds more dynamic range and is designed on the assumption that the footage will be graded. Canon Log 3 keeps the easier handling of the original Canon Log while extending its range, so it needs less work. For most YouTube projects Canon Log 3 is the practical choice.
Can I grade Canon Log 3 in the free version of DaVinci Resolve?
Yes. The Color Space Transform, Resolve Color Management and LUTs are all in the free version. Temporal noise reduction, which helps with noisy log shadows, needs DaVinci Resolve Studio.
Should I use a LUT or a Color Space Transform for Canon Log 3?
In DaVinci Resolve, use a Color Space Transform. It converts Canon Log 3 mathematically and lets you choose how highlights roll off. A conversion LUT is a fixed table that assumes exposure matched the specification.
