As stated in the previous section, a bitmap is a map of pixels and usually represents a continuous tone photographic image. These images are created at a specific resolution that will only be accurate at the original image size. Therefore, a little planning should be done before scanning a photograph for print.

Two important factors in determining the proper resolution are the line screen your project will be printed at and the final size of your image. In most cases, Goodway prints with a 150 line screen (or lpi).

Scan at no more than twice the line screen ruling that will be used to print the file. If the file will be processed using a 100 line screen ruling, then scan the image in at no more than 200 DPI. If the screen ruling is 150, then scan it at no more than 300 DPI. Scanning at higher rates does not improve the quality. It does, however, increase the amount of imagesetter processing time. The difference between scanning a 5 by 7 black-and-white image in at 300 DPI versus 600 DPI is about 9mb. dpi = 2 x lpi x percent of the original size

*When dealing with large files, you can reduce the "resolution to line screen" ratio to 1.5 without very noticeable degradation of quality. This reduction can have significant effect on final file sizes.

Please remember that resizing bitmaps affects the resolution and may cause complications, so it is best to know the final size of your image when scanning.