Colour Management – Questions
1. What is the purpose of colour management ?
To maintain consistent colour appearance across different devices and throughout the working process.
2. What problem makes colour management necessary ?
Different devices each have a different gamut, this is the range of colours that a device can produce.
3. What are the components of a device profile (ie what information do they contain) ?
The colour gamut of that device and the instructions which can be used to convert a colour space into or out of that gamut.
4. What is the difference between a device profile and a working space ?
A device profile relates specifically to a device and the colour space it uses is the gamut of the device. The working space is a range of colours that doesn’t specifically relate to a device.
5. What is a ‘reference colour space’ and how are they used ? Give an example of one.
This is a defined device independent space that is used as a reference point in the convertion process between two colour spaces.
6. What is the difference between ‘calibrating’ and ‘profiling’ ?
Calibrating is using adjustments to get a device to it’s maximum potential, profiling is a process to measure the potential of the device.
7. What is a Rendering Intent ?
The instructions for converting from one space to another, particularly useful when colours are found outside of one of the gamuts of the devices used in converting process.
8. Which Rendering Intents are most useful to photographers, and when would you use each of them ?
Absolute Colourimetric (used for proofing purposes, eg. Simulating on one printer what another will look like), Relative Colourimetric (brings out of gamut colours into boundary of target space, does not adjust any other colours), Perceptual (takes out of gamut colours and assigns them to closest in gamut colour, as well as changing other colours proportionately, maintains differences between colours)
Gamut: The range of colours a device can produce.
Colour Management Workflow Diagram by Geoff Woolfenden
Tutorial: In small groups calibrate a computer monitor.
We ran the calibration process twice. Below are screenshots from the first process.
Before the Calibration Process
After the Calibration Process
The second time we ran the calibration process we ticked the box native white point. The native white point is supposed to preserves the maximum possible color range on LCD monitors.
Below are two more screen shots for comparrison.
After the Calibration Process Using Native White Point
