Support - Choosing Scanning Parameters
“Actually, it's more of a guideline than a rule...” - Dr. Peter Venkman
200DPI B&W for plain vanilla text documents is the fastest to scan and smallest to store.
The quality is like a good fax. Highly legible but slightly ragged or slightly fuzzy, depending on the zoom level.
7pt text is legible but begins to look broken.
Printed, the text may look somewhat ragged or pixelated, especially when printed on a 400-600dpi laser printer.
File size: Typically 40KB-80KB per page in TIFF or PDF.
300DPI B&W is quite good quality for text documents.
It may still have a somewhat 'harsh' look; irritating to some people (me...), invisible to others.
Prints quite well - distinguishable from the original, but usually just as legible.
File size: 60KB-120KB depending on the amount of text on the page.
Note: B&W scanning can be thresholded or halftoned. Thresholding works well for text and line-art, but does 'bad things' to gray areas, shaded artwork and photographs. (See the photo in the B&W examples above-right.)
Halftoning preserves shades of gray and color and photographs, in a low-res grayscale way, but tends to push up file size, radically if large areas require halftoning.
200DPI 8-bit grayscale looks very nice. Graphics and photographs are preserved well (without color of course).
Looks great on-screen. Slightly 'soft' when printed, not apparent to a casual observer.
File size: 150KB - 250KB or more per page in PDF, depending on page content.
You can get smaller or larger files by adjusting the JPEG quality setting.
3.7MB in TIFF! (there's a long story there, ask if you are interested...)
- 150DPI grayscale or color for photographs, gives you an image that looks great on-screen, and looks good when printed with consumer/workgroup color printers, as long as you print to the original size or smaller.
File size: 74KB PDF for a (color) 3.5" x 5" photographic print, using JPEG Quality 75.
200DPI color for photographs is 'archival' quality for most people. You can zoom in and see details that only a CIA analyst would notice in the original photo.
Just for grins, the example document is available at right in 200DPI color.
File size: 124KB PDF for a (color) 3.5" x 5" photographic print, using JPEG Quality 75.