You have the option of using a free viewer to see .sid format maps that you save to your computer . To use the viewer, install it on your machine. The average file size in the .sid format is 5 megabytes. You need no special viewers to view most photographs in the American Memory collections. These are of higher resolution and larger file size than .gif or .jpeg images and require a special viewer.
Some viewers offer the option of scaling the image to fit inside the viewing window.
NT - ThumbsPlus Top of Page Video All American Memory film collections require special viewers. For detailed playback information, see Video Viewer - Additional Playback Information . This format offers smaller, downloadable files and allows films to be viewed on lower-end computer systems. See a list of American Memory film collections in QuickTime format . Films presented in .mpg format are higher resolution and better quality than the equivalent QuickTime versions.