The GoProTune LUT Pack has been specifically developed due to a lack of proper technical transforms available for GoPro Protune & GP-Log footage. In addition to a lack of accurate transforms, there is also a general lack of information with regards to the Protune Gamma curve and the Native Color Gamut parameters.
Whilst the Protune curve is considered an SDR curve, it can also be useful in HDR workflows as up to 3+ stops can be recovered in ideal scenarios without significantly visible noise.
Shown below is a Characteristic Curve of the Protune Gamma with the curve also under-exposed by 1, 2 and 3 stops respectively.
For reference, the table on the right identifies the IRE values that Protune can be exposed to with reference to an 18% Middle Gray card. Shown are the standard Protune curve as well as the IRE values when under-exposing by 1, 2 and 3 stops respectively.
|Protune – 1 EV||52%|
|Protune – 2 EV||37%|
|Protune – 3 EV||23.7%|
The LUTs should be copied to the designated LUT folder hierarchy of your desired Application or Monitoring System. This will vary from one application and Recorder/Monitor to another.
Depending on the target application, the LUTs may need to be copied to some of the following folders on Windows based systems:
- C:\ProgramData\Blackmagic Design\DaVinci Resolve\Support\LUT\
- C:\Program Files\Adobe\Common\LUTs\Creative
- C:\Program Files\Adobe\Common\LUTs\Technical
Depending on the target application, the LUTs may need to be copied to some of the following folders on Mac OS systems:
- /Library/Application Support/Blackmagic Design/DaVinci Resolve/LUT
- /Library/Application Support/Adobe/Common/LUTs/Creative
- /Library/Application Support/Adobe/Common/LUTs/Technical
Depending on the target application, the LUTs may need to be copied to some of the following folders on Linux systems:
This LUT pack consists of 86 LUTs spanning the Native, WIDE (GoPro Labs firmware) and Rec.709 source color gamuts and various output Gammas in order to provide support across a large spectrum of workflows. The LUT Pack includes Lookup Tables supporting Protune Flat and the newly developed GP-Log for HERO12 Black cameras.
GoPro Protune footage is always encoded using Data levels (0 – 255). Where applicable, ensure Full Data levels are explicitly set in the clip attributes.
The pack includes a number of output variations with the following specifics:
- Technical Transform LUTs with output to P3 D65 or Rec.709 Scene
- Technical Transform LUTs with output to P3 D65 or Rec.709 Gamma 2.2
- Technical Transform LUTs with output to P3 D65 or Rec.709 Gamma 2.4
- A series Output LUTs that add +1, +2 and +3 stop exposure adjustments with proper Tone and Gamut mapping output to Rec.709 for either TV (Broadcast) or Web scenarios.
- A series of HDR LUTs with +2 and +3 stop exposure adjustments with output to 1000 nit PQ ST2084 HDR or HLG HDR
The Technical LUTs provide a base conversion, from which additional color grading and tweaking can be done. On the other hand, when the Tone Mapped Output LUT is selected, no further color grading or tweaking is required as this will map the color and dynamic range to cover the Rec.709 gamut and output levels accordingly.
Due to the Protune curve’s overall high value of 68% IRE for middle gray and relatively great dynamic range for the sensor size, most footage can generally be under-exposed by 1-2 stops with an adjustment made in post to recover the midtones and expand the highlights. The Tone Mapped LUTs are therefore included in +1, +2 and +3 EV increments.
Similarly, when middle gray is under-exposed by 2 stops at 37% IRE, the Protune curve provides nearly 4.5 stops of highlight latitude relative to the under-exposed mid-gray. This is particularly useful in HDR workflows and the HDR LUTs have also been provided to allow for a direct HDR conversion to either PQ or HLG.