In most cases, differences between printed and on-screen images can be attributed to a poorly set-up monitor. Never forget that when working with any digital images, you are not seeing the image information directly, instead you are only seeing a second-hand account of the image information, related to you by your monitor. It's therefore up to you to ensure that your monitor relates that information as accurately as possible.

Thankfully, when Adobe Photoshop is installed on your computer, it also installs a very useful little utility that goes a long way towards optimising your display. This little program is called Adobe Gamma, and we shall be showing you how to use it effectively further down the page.

Firstly, however, you will need to prepare your monitor and it's surroundings:

• Make sure that your monitor has been switched on for at least 1 hour before attempting to optimise it. This allows it to stabilise. In fact, you should do this before any image manipulation work.
• Use the onboard controls of your monitor to set it's White Point to 6500K [also referred to as D65] - refer to your monitor manual if you don''t know how to do this. Most monitors are shipped from their factories with White Points as high as 9300K, which is fine for general use, but too bright for image manipulation with a view to outputting to print. 6500K is universally regarded as closest simulation of daytime reflected light. If the monitor you're using doesn't have the option to adjust it's White Point and you intend to do a serious amount of digital image processing, you may wish to consider purchasing a more appropriate monitor.
• Ensure that the room the monitor is situated in has lighting that is suitable for image work - not too bright, but not too dim as to be uncomfortable and lead to eyestrain. Ideally, the screen of your monitor should not be exposed directly to any light-emitting sources.
• Most video cards have some form of colour-correction/alteration control available as part of their driver software. Switch off or reset any video card-based colour compensation, in order to avoid inaccuracies and possible confusion.

If you're a Windows user, Adobe Gamma can be found in the Control Panel [Start>Settings>Control Panel>Adobe Gamma]. Mac users will find it at [Apple Menu>Control Panels>Adobe Gamma]. Start the program and you should see this window:

You are about to create a new customised colour profile for your monitor, based upon the profile suggested as a starting point by the program. This will be your general, all-purpose colour profile. Give it a verbose description, using the monitor model name, the white point, the Gamma setting [which, broadly speaking, will be 2.2 for Windows PCs and 1.8 for Macs], and the date: something like "Mitsubishi Diamond Plus 91 Monitor 6500K G2.2 13thApril2002".

Even though it is recommended that you stick with the suggested profile, There is a possibility that there will be an existing colour profile that corresponds more closely with your monitor - hit the "LOAD..." button and browse the colour profiles that appear:

If you choose to start from one of these colour profiles, you will be prompted to save your newly-created profile - remember to alter the description and save the profile using a different filename!

Once you are happy with your starting profile, click NEXT to continue...

This next step determines both the Black Point and the White Point of your monitor - in other words how your monitor will display the darkest and brightest colour information, respectively.

There is no trick or secret to this step, just follow the on-screen instructions. Just remember that you want the centre square to be slightly visible against the black, and make sure that your white frame is still bright.

Once you are satisfied with your Brightness and Contrast settings, you may wish to save them [if your monitor has that facility] - although you shouldn't need to alter them at all from now on. Your monitor will now depict shadows and highlights with reasonable accuracy, leaving only the midtones to optimise. But before you do that, you have to inform Adobe Gamma of your monitor's phosphors. Click NEXT to proceed..

If these numbers don't mean anything to you, or don't seem to correspond with any information supplied by the monitor manufacturer - DON'T alter them! On the other hand, if they correspond with manufacturer's information, enter your monitor's phosphors' values and hit OK.

Either way, hit the NEXT button to proceed to the Gamma/midtone optimisation...

Ensure that the "View Single Gamma Only" checkbox is checked, initially, so that only the one grey box is visible on screen as shown above. Then adjust the slider until you can see no distinction between the inner box and the horizontally-banded box. It helps if you squint at the boxes from a distance while doing this!

Once you are satisfied that you have acheived optimal gamma, uncheck the "View Single Gamma Only" checkbox, so that the grey box changes to three colour boxes - Red, Green and Blue:

Now adjust the three gamma sliders as before [again, squinting helps!], concentrating on one at a time. This process is necessary to compensate for any colour casts that your monitor may be outputting. [More likely than not, a monitor's Red, Green and Blue guns [the bits that fire electrons at the Red, Green and Blue phosphors which cause them to light up, or phosphoresce, and form the display] will not behave equally, so that while your video card is happily outputting a neutral [neither 'warm' nor 'cool'] display, your monitor isn't.].

With this compensation now done, you may wish to select a particular gamma. Windows users should select "Windows default", and Apple users should select "Macintosh default" [if they aren't automatically selected for you]. Onwards to White Point temperature...

As mentioned in the opening paragraphs at the top of the page, you should have set your monitor's white point to 6500K [D65] if possible. This is the option that you should select now, unless you know your monitor to be using a different value.

You will notice that you also have the option to manually measure the white point. It is strongly recommended that you do not use this method of determining white point unless as a last resort, as it is simply not very accurate [When they say "estimate", they mean it]. If you must, however, follow the instructions that are provided when you click on the MEASURE... button.

Hopefully, you should see a difference between the 'Before' and 'After'! The 'After' should be as neutral as possible, and it will probably seem brighter due to the corrected white point and midtones.

Click on FINISH to save your newly-generated optimised monitor profile. Once you have saved it Adobe Gamma will automatically apply it to your display from now until it is instructed otherwise. The new profile you have just created will be loaded into your computer's memory every time you switch your computer on - so you don't have to go through the above process again, or manually load it into memory, or anything like that - once it's done, it's done!