Colour Control on Monitors



In this article we present the major options for colour managing your monitor, in order of most accurate to least accurate. The first two options, both hardware based, are very accurate and we strongly recommend using these systems if you want to achieve quality results with digital imaging. The other methods are all based around judgements made by eye and are therefore not capable of really accurate results.

We suggest you start by first reading our article on Calibrating Versus Profiles if you don't have a clear understanding of what calibration and profiling are and how they are different.

Methods for colour management with monitors

  • Direct Hardware Calibration: Direct calibration using the high bit depth tables in your monitor.
  • Software Calibration (with a Hardware Device): Classic hardware device based calibration using the 8 bit tables in your video card.
  • Purely software calibration: Using your operating system's in built calibration tool.
  • Calibration by eye: The bare minimum method or using 'The Shirley System'.

Direct Hardware Calibration

Direct calibration using the high bit depth tables in your monitor

Direct Hardware Calibration is the most sophisticated and most accurate method of monitor calibration available

This is the most sophisticated and most accurate method of monitor calibration available. This method requires dedicated hardware inside the monitor and is only offered by premium monitors such as the Eizo ColourEdge line of monitors. All NEC colour critical monitors can be hardware calibrated using SpectraView 2.

This monitor specific software allows you to calibrate directly using the higher bit depth processing available in the ASICs/LUTs in the back of the monitor. Because the calibration is being done with higher order mathematics, it means the final result is a smoother calibration across the available gamut - particularly noticeable in gradients and deep shadows.

The tables in these monitors are typically 10, 12, 14 or 16 bit versus the 8 bit table standard in video cards (see the next section). This means instead of just 256 levels being available, there are from 1024 to 65 336 levels available! The result is much more accurate tone placement and separation.

If you want the best, most accurate calibration, this is the way to achieve it.

You can also read some notes from Eizo on hardware calibration below.

Software Calibration (with a hardware device)

Classic hardware device based calibration using the 8 bit tables in your video card

Classic hardware calibration (now often referred to as 'software calibration with a hardware device') is the most appropriate type of calibration for most users with standard monitors. It is affordable, simple, and offers good results.

This method of calibration uses a colorimeter device (commonly called a Spyder based on the name of the first really popular brand), to accurately read the colour coming from your monitor. A translation table between the colour you should be getting, and the colour you actually are getting, is created and installed in your video card's colour look up table. Therefore the signal leaving your video card is modified to produce more accurate colour from your monitor.

In the long term if you're serious about getting good results from digital imaging, this will be one of the best purchases you will make. Relative to other costs in photography, colorimeters are very good value for money and are extremely useful devices that will pay for themselves in a short time by saving you money day after day on colour misadventures.

Read our Calibrator Recommendations for more information on the current available calibrators. You can also read some notes from Eizo on software calibration here.

Purely Software Calibration

Using your operating system's in built calibration tool.

If you're not ready to outlay the money for a calibration device yet, then the next best alternative is using your operating system's in built calibration tool - both Windows and Mac 10.X have utilities for this.

On a PC

In the control panel, you will find a tool called 'Colour Management'. On the advanced tab of this tool is an option to 'Calibrate Display'.

On a Mac

The ColorSync utility offers similar functionality. It's a very long way from the quality of hardware calibration but definitely better than using nothing. Just start the software and follow the on screen instructions.

Failing the use of hardware calibration, or something similar, your video card may come with calibration software. This is not a very accurate tool, but once again will still (probably) be better than nothing.

Calibration By Eye

The bare minimum method - Basic monitor calibration.

If none of the above options are available to you, then follow the instructions below to do basic monitor calibration. This will make no permanent changes to your system but will be a good start for tuning your monitors controls. You may need to use the physical monitor controls on the monitor itself, and/or the software tools that came with your video card - found under the system/display settings on your computer.

If you adjust your monitor to the settings suggested here, you will find images all over the web display more accurately.

With this test image

Step One: Brightness and contrast (the top row)

You should be able to see all this:

  • 20 sections of equal width and different tone (If you don't see 20 different tones, you may need to lower your monitor's contrast).
  • The darkest section must be pure black (If black is not pure black you need to darken your monitor until the point you see pure black).
  • The lightest section must be pure white (If white is not pure white you need to lighten your monitor until you see pure white).
  • If both black and white are not pure, try boosting the overall contrast.
  • There must be no hint of colour anywhere along the grey spectrum (If there is a colour cast (ie the greys are not pure grey), try and adjust the colour balance).

Step Two: Colour (bottom 3 rows)

Once you have adjusted everything as precisely as you can, look at these test images (Red, Green, Blue):

  • There are 16 clearly defined sections in each strip.
  • If you cannot distinguish between them towards the dark end in any of the strips, you may need to lighten that respective colour, or darken the other two colours.
  • If you cannot distinguish patches towards the light end in any of the strips, you may need to darken that respective colour, or lighten the other two colours.
  • You can also try to work with saturation controls for the individual colours, if they are available in your monitor controls/software.
Matching your monitor to a lab print - the 'Shirley' system

The classic approach that many labs take to solving the colour management problem is the ‘Shirley’ system.This system involves taking a print out of an old 1970s photograph from the lab’s printer (of a woman apparently named Shirley) and twiddling your monitors controls until your screen looks roughly like the print out.

This calibration method is fundamentally wrong and fortunately most labs are beginning to realise this. Trying to match your screen with a print is far too adaptable, and far too influenced by surrounding factors like light, the colour of your shirt, what else is in your field of vision. Your eye simply can't make the measurements required for accurate colour, so quite simply the Shirley system can not work with anything like the accuracy of hardware based calibration.

Furthermore, your monitor does not offer controls that replicate the sort of adjustments that a proper calibrator can make, so there is simply no way you can achieve a calibration that is anywhere near the quality you can get using the first two methods above. This system also permanently ties you to printing at one lab to get best results, as you have calibrated your monitor solely to their printer.

Getting good colour/tonality is all about science – not art. Art is what you actually do with the colour, but viewing, reproducing and printing colour accurately is all about science. There needs to be some sort of objective standard for colour, and then to calibrate all your devices to that standard, so they all produce the same colour. To achieve that with any level of accuracy, which is essential to getting good results from digital images, you really need to use a hardware based calibration approach.