Chapter V, Printing Digital Images: Lesson II Picture Display and Computer Monitors http://www.kodak.com/country/US/en/digital/dlc/book3/chapter5/lesson2/p01.shtml

For most people, the first time they see their digital pictures they will be looking at a computer monitor or the LCD screen of their digital camera. It is very important to realize that the way a picture looks on a computer monitor or LCD screen is not necessarily the way that it will look when printed on an inkjet printer.

An initial test print should always be made before making major adjustments to improve print quality. What the picture looks like on a monitor only provides a starting point for evaluation. It’s the quality of the print that really counts and a test print will provide important indications about adjustments that may be needed.

WYSIWYG is an acronym often used to describe this situation WYSIWYG is an acronym often used to describe this situation. "What You See Is What You Get" is an ongoing goal in the development of digital photography. The reason WISIWYG is so hard to achieve is that monitors and printers use two different ways of creating a picture.

With a computer monitor, the computer’s video card converts computer information about a picture into electrical signals that stimulate phosphor coatings inside the monitor. These spots of glowing phosphor transmit varying amounts of red, green, and blue colored light. Our eyes mix these spots of color together and are seen as a picture on the screen.

A printed picture is formed when small drops of cyan, magenta, yellow and black ink are placed on paper. Our eye mixes the light reflecting from the spots of colored ink and the results are seen as a picture on paper.

As a result of these fundamental differences in how each device creates a picture, we can not assume that using imaging processing software to make a picture look good on a monitor will mean that that picture will also look good when it is printed.

Most people have an ability to see a wider range of brightness and colors than can be captured and reproduced in a picture. Both print and monitor display methods have limits as to how accurately they can produce all the various shades of a given color. In some cases certain colors and brightness can not be reproduced at all.

Imagine a paint palette with 20 different shades of red Imagine a paint palette with 20 different shades of red. When viewed separately, each of these colors is considered red, but when viewed together the tiny differences between them are noticeable. It is the same when reproducing a digital picture. One company can choose "brick red" as the color red shown on their monitor, while another company's printer can show "candy apple red." Both colors are red, but they look different when held side by side.

Computer monitors will have different resolution capabilities just as any other digital device. Spatial resolution is usually set at 96 dpi (depending on the computer system used). Most monitors will support several brightness resolutions (also referred to as color bit depths) and can be set using the computer’s display control panel. Typical brightness resolutions include 24 bit – at this setting the monitor will be able to display millions of specific colors 16 bit - at this setting the monitor will be able to display thousands of specific colors 8 bit - at this setting the monitor will be able to display 256 specific colors

A picture containing a wide range of colors will obviously look better shown on a monitor capable of displaying millions colors then it would if the monitor was set to a lower color bit depth. Some older computer systems may be limited to displaying only 256 specific colors. As a result, these systems will be limited when it comes to adjusting pictures on screen for later printing with an inkjet printer.

A computer monitor can vary significantly from one manufacturer to the next. An example of this can be seen in the television department in any consumer electronic store. Several hundred televisions displayed side by side and no two pictures will look the same

In most computer monitors, there will be subtle changes in how colors are displayed as the monitor warms up. Monitors should always be allowed to warm up and stabilize 10 – 15 minutes before they are used to make decisions about picture quality

The consistency of a computer monitor’s display will change with age as the light emitting phosphors degrade over time.

There are also several other factors that effect what is seen when comparing a print to the computer monitor. These include: The color and intensity of the ambient light in the room around the monitor Dominant room colors including wall paper, carpeting and draperies The color and intensity of the light used to view the final inkjet print