You can choose how much data your scanner should extract from a picture after it has been captured. The more dots per inch there are, the greater the resolution and the more detail it will preserve. For instance, a smartphone screen that displays photographs at 150 to 350 dpi resolutions produces a far smoother image than a 72 dpi resolution, which is about similar to a halftone photograph in a newspaper. The sort of document your organization is capturing and how you plan to use it ultimately determine the ideal resolution to scan at.
Resolution vs. Size
The size of an image and its resolution go hand in hand. Film scanners function in this manner; if you take a little image and scan it at a high resolution, you can spread those pixels out and reprint it at a large size. On the other hand, you can reduce an image after scanning it at a lesser quality if you have a large image that you just require for a little size.
While these are merely broad guidelines, it’s important to keep in mind that if information is lost, it cannot be recovered. If you’re unsure which resolution to utilize, scan with more pixels than necessary. Although having larger files is annoying, not having the resolution you need to finish your project is less inconvenient.
Best Document Resolutions
Although they feel that a 200 dpi resolution is sufficient for reproduction, the National Archives and Records Administration, the department of the federal government that, among other things, is in charge of keeping the original copies of the Constitution and Declaration of Independence, thinks that the best dpi for scanning documents is at 300 dpi resolutions. The resolution of a fax machine in “fine” mode is around 200 dpi. Set your scanner to its greyscale or black and white mode when scanning papers with black and white text to produce smaller files.
Best Photo Resolutions
Hewlett-Packard, a manufacturer of printers and scanners, advises scanning photos at a resolution of at least 300 dpi. They claim that a 300 dpi resolution is sufficient to produce a print of high quality from the scanned file. However, 300 dpi won’t provide you with enough resolution if you wish to enlarge the print and reprint it at a higher scale. So, just in case, you might wish to scan at a greater resolution. But be sure to properly examine the files. Rarely is the ideal resolution for scanning images greater than the photo’s quality. A higher resolution scan won’t actually provide you additional picture information if the original photo you are scanning was printed at 300 dpi. It will merely enlarge the dots that made up the original image.
Best Film Resolutions
It’s a little trickier to scan content from film, such as slides and transparencies, because you often acquire the image knowing that you’ll be enlarging it for printing. Thus, you require a resolution that is far higher than what you would use for a picture or a paper. Additionally, the effective resolution of film is substantially over 5,000 dpi. Take the image’s biggest print size in inches and multiply it by your print resolution to get the precise resolution. For instance, you would want a 2400 by 3000 image file if you wanted to produce 8 by 10 prints at 300 dpi. The resolution that will extract that image size from the film can then be determined using that specification. You would require a resolution of roughly 100 pixels per mm, or 2,540 dpi, for a 24-by-36mm slide. Scan at 2,400 dpi or more if you don’t want to do any math.
