SpaceMatch DCM Features
Accurate colour management is a critical part of any post-production workflow, and the use of non-industry specific creative systems within film and TV workflows can be a serious problem for post-production facilities if ICC profiles are employed. The ability to colour match the gamma and colour of temperature displays using 1D LUTs generated with LightSpace CMS means work can be accurately viewed on any PC based systems, without running in the issues associated with ICC profiles.
Note: for accurate display calibration 3D LUTs are required, which requires the use of displays with 3D LUT capability built-in, a LUT box placed in the image signal path, or the use of graphics programs with 3D LUT capability.
As with any Graphics Card based calibration, the calibration via SpaceMatch DCM is based on 1D LUTs, not 3D, so the calibration is gamma and colour temperature (grey scale) only, as Graphics Cards cannot control display gamut.
This is true for ANY Graphics Card or Windows OS wide (ICC) calibration.
(Mac can perform OS wide Gamma and Gamut ICC based calibration, but suffers a number of other colour related issues that makes it impossible to rely on such colour calibration.)
One of the main uses for SpaceMatch DCM is to ensure there is no internal ICC/Graphic Card calibration active, enabling clean HDMI output for external display profiling and calibration via the LightSpace CMS PC's inbuilt HDMI output.
See: Direct HDMI Calibration.
Issues with ICC Profiles
ICC profiles do not directly 'calibrate' a display, but act as a 'conversion' process between the 'image' and its associated colour space, and the actual colour space of the display being used. This 'conversion' process attempts to make the images seen on the associated display 'look' correct, without actually calibrating the display. If the same images are shown on the same display via a different graphics program there is no guarantee the images will look the same.
Graphics cards have the ability to use a 1D LUT for gamma and colour temperature (grey scale) management, which 'should' be understood by any ICC profile. Guaranteeing this is the case is not always as expected.
The main issues with the use of ICC profiles are:
- Does the graphics program support the use of ICC profiles?
(Many film and TV programs do not)
- Which ICC profile will the graphics program use, if different ones are available?
- Is the ICC profile based on a 1D LUT + 3x3 matrix, or 3D LUT?
(1D LUT + matrix will never be as accurate as a 3D LUT)
- Will the ICC profile understand and correctly manage any active VCGT?
- When footage is saved will the correct ICC be burnt-in to 'correct' the footage colour?
(If the same footage is played back on a correctly calibrate broadcast display will it be 'correct'?)
Display calibration for the film and TV industry should really be directly associated with the display, as an internal 3D LUT, or a single 3D LUT at the end of the graphics path, either via a LUT box or held as the final element within the graphics software, so acting immediately before the display. In this way the display is effectively calibrate in isolation, as it should be.
ICC profiles rely on the graphics program being ICC compliant, so link the 'calibration' between the software and the display, with inevitable potential issues.