Correct Colour and Contrast

Even straight from the factory computer monitors are seldom well enough adjusted to give accurate colour, or optimum contrast and brightness (luminance) for quality photographic work.

In the early days of colour television, people simply accepted that “different tellies look different” and you got used to your own screen.  Many people think that’s the same with computer screens.  Different people’s screens looking different would be fine if there was never any occasion where picture files were going to be shared.  But photographs are made to be shared.

Imagine your computer monitor has its contrast set too high, and it makes green colours over saturated.  When you are editing your images you will probably decrease the contrast in the image, and decrease the green saturation (or increase the magenta colours) to make the picture look right on your screen.  When you send the image to someone else who has a correctly adjusted screen, projector or printer, your picture will be flat and lifeless, and have a magenta colour cast.

You can’t do anything about other people’s monitors.  Not all will be perfectly adjusted.  But if yours is wrong, it doesn’t matter whether theirs are right or wrong, your images will not look right.

The first step is to calibrate your monitor to ensure the resolution, brightness and contrast of your monitor are set to their optimum.

  • Set your monitor’s resolution to it’s ‘native’ value.  (Look in the manual, or look  up “Native Resolution MY-MONITOR-BRAND MODEL” on the internet.)
  • Adjust the brightness of the screen so that it is about as bright as a piece of blank white paper sitting on the desk beside you.  Brightness should be lower in a dimly lit room, and higher in the brightly lit room.  Somewhere between 90 cd/m2 and 120 cd/m2 will be right.)
  • Set the ‘gamma’ value of the monitor to 2.2 if you are able to adjust it.
  • Go to http://www.lagom.nl/lcd-test/ and work through at least the contrast, display settings, black level, white saturation, and gradient screens, making adjustments to brightness and contrast as required to achieve optimum output.

Some newer monitors have controls that allow you to set approximate colour values that will not be wildly wrong, especially if the monitor is reasonably new.  If your monitor’s settings menu allow:

  •  set the colour temperature (or white point) to D65, or 65K, or 6500 ºK
  • Set the ‘colour setting’ to sRGB (If the monitor is a ‘wide-gamut’ monitor, and it allows you to set it to AdobeRGB choose that, (and congratulate yourself!))

To precisely standardise the colours on your screen, you really need to use a specialised piece of equipment called a colorimeter or spectrophotometer.  (See this page about making an ICC colour profile for a monitor).  A couple of club members have got colorimeters.  Ask around at a meeting, they may be able to help.

Once your monitor is reasonably well calibrated you can be confident that what you see when you make any changes to your digital images will be the same that anyone else with a reasonably well calibrated (and colour profiled) would see when looking at your digital image.

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