A. Monitor Calibration

If some of the images on my website seem a bit dark that's because I seem to have a preference for dark images! However, to ensure that the images are being shown correctly, your monitor should be calibrated and set to a luminance level of 90 cd/m2 (ie 90 candelas per square metre). The ideal way would be to use a hardware-based calibration device. In lieu of this, a "quick fix" process for getting your monitor brightness/contrast to an approximately correct level is to make use of the gradient chart shown on this page.

Step 1:

Set the monitor "CONTRAST" level to the maximum value. If image distortion occurs then lower CONTRAST until the distortion is reduced.

Step 2:

Adjust the monitor "BRIGHTNESS" level so that you can see all 21 distinct shades in the test bar shown below.

It helps if the room lighting is not too bright, and that the monitor has been in use for at least 30 minutes. Not all monitors will be able to pass this demanding test. In particular, unless ambient lighting is very low it may be difficult to differentiate between the two darkest levels.

If my images still appear dark, then sorry, that's the way that I've done them. I did say that I prefer dark images!

I've noticed that a lot of new flat-panel monitors (eg LCD monitors) being sold today have luminance levels set at 200+ cd/m2 which is VERY bright. These high luminance values certainly make the images stand out! So, in general, those using older CRT monitors may see darker images than those using newer LCD monitors. It took me a long time to get used to using 90 cd/m2 on my LCD monitor instead of the 190 cd/m2that it was previously set to. At first 90 cd/m2 appeared too dim. You may experience the same!

Note that the chart was converted from LAB to RGB mode for display on the web. The greyscale values are created in steps of 5 in the LAB Luminous channel, and with the A and B channels both set to zero. You should therefore not see any colours...only grey! Unfortunately, I have found that a number of LCD/TFT monitors exhibit quite noticeable colour artefacts such that each greyscale bar appears to have a different tint from other greyscale bars resulting in some looking red, some green, etc. You'll have to decide for yourself if you want to (or even can) rectify this.

For even more information, calibration charts and links to free software monitor calibration tools then please visit Norman Koren's site. Highly recommended!

B. My display settings and measurements

1. Colour temperature = 6500K

2. Gamma = 2.2

3. Calibrated Display Luminance (Candelas per square metre)

Black = 0.00
White = 88.9

4. Calibrated White Point (CIE x, y)

0.313 0.324

5. Phosphors (CIE x, y)

Full Red = 0.624 0.352
Full Green = 0.277 0.612
Full Blue = 0.149 0.049

6. Delta E Colour (Luv)

White Point = 0.9
50% Gray = 0.9