UM:Projects Project Colour Scaling

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Project Colour Space and Scaling

The project Colour Space and Video Output Scaling are per project settings and defined on the main Project Setup screen.


These modes affect :

  • SDI video capture and layoff
  • Colour space scaling on import/export of media
  • Timeline monitoring via SDI – including : Timeline filler, Transitions , Pan/Scan blanking, Fade to Colour
  • Colour tool behaviour (black/white pivot points etc.)
  • Scene detection

Be careful with these settings.

If you change the colour space and/or scaling on an existing project, a warning dialog will request confirmation before application of the change. The change will affect SDI monitoring, capture and layoff settings and the mode used in new colour tools. It may also cause a re-render of colour adaptive tools on your timelines.

Colour Space


A Colour Space is an abstract (mathematical) model describing all possible colours available, given certain setup constraints. Such a model will relate numbers to colours.

The Colour Spaces of a project can be set as follows :

Video SMPTE Refers to the standard legal video signal 0-100%

10 bit Range : 64 - 940
Values can exist outside of the 64-940 range (super-blacks and whites)

Colour tools pivot around the SMPTE values 64 and 940

Full Range Refers to a Computer Generated Render (CGR) mode covering the full range of bit-depth data values.

10 bit Range : 0 - 1023
Note that this is not a legal SDI video range.

Colour tools pivot around the Full Range values 0 and 1023

Cineon Log Full range but logarithmic data.

Colour tools pivot around the LOG values 95 and 685

Video Log Video SMPTE range but logarithmic data.

Colour tools pivot around the Video SMPTE values 64 and 940.

ACES This is the Academy Color Encoding System.
See : ACES Whitepaper (PDF) in Resources.
Video Output Scaling


For scaling output SDI video, the following modes are available :

Clip to SDI Legal This is a hard clip where values outside the legal SDI range (4-1020) are removed.
Scale to SDI Legal Values outside the legal SDI range (4-1020) are scaled to be SDI legal.
Scale to Video Legal Values outside the legal Video range (64-940) are scaled to be video legal.

For a brief overview of Full Range/Video SMPTE scaling, see the Appendix.

Colour Tools

The colour adaptive tools have their own independent scaling mode option with the default taken from the main project setting. The scaling mode will affect the black and white points used and the way the tool pivots around them when adjusting parameters.

Colour pivot linear cgr.png Colour pivot linear smpte.png Colour pivot linear film log.png
Linear (Full Range)
Pivot around 0.
Video level graticule.
Linear (Video SMPTE)
Pivot around 64.
Video level graticule.
Cineon Log
Pivot around 95.
Log/Cineon level graticule.

You can modify the black, mid and white points of the scaling modes via the colourPivotPoints section of the general.prefs file.

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