Image resolution refers to the size your image appears on a computer monitor rather than the physical dimensions an image will print. The pixel dimensions of an image identify the resolution. Many digital cameras let us change image resolution. So, before we take a picture, we must determine the quality of an image first by using the highest quality setting available on the camera. Therefore, set your camera for the best image quality if you want to obtain high quality photos.
According to the article "Image Quality - An Explanation" by Julian Foster which was posted at www3.teleplex.net, a truly high-resolution digital photo can be anywhere from 12MB (for a 4-by-5-inch image) to 70MB (for a two-page-spread photo). The CD ROM photo collections currently on the market have files ranging in size from 500K-22MB. He added that image resolution, the amount of information in a digital file, is measured in dots per inch. Screen frequency, the density of the lines of dots used to print a continuous-tone photograph, is measured in lines per inch. Newspapers typically use a coarse line screen of 85 lpi; in-house publications, 100 to 120 lpi; and glossy magazines & good quality offset lithography, 133 to 155 lpi.
Proper resolution is truly important for good printing. And to achieve this, you must always remember some rules that include the following: the text must be 400dpi at the final size in the layout; the images must be 300dpi at the final size in the layout; the dimensions of the resolution and size are inversely proportional to each other so, if you enlarge an image, you lower its resolution and if you reduce an image, you increase its resolution; how an image is originally acquired will determine its resolution and thus, the size it can print at for clear and crisp printing; and low resolution images print with jagged edges and appear fuzzy.
Indeed, when deciding on the print size of your image, you must choose a size that is appropriate to the resolution of the image you are supplying. The size to which your image can be printed without a loss in quality depends on the resolution of your image. Remember that the higher the resolution of your image is, the better the quality of the image when printed.
Most digital cameras allow you to select a combination of resolution and quality from the settings menu. In order to obtain an optimal print out, you must set your digital camera at the highest possible resolution and quality. Always remember that the higher the quality, the larger the image file will become. So folks, make sure you have sufficient room on the memory card!