I am looking for a digital camera to capture images to be used in an upcoming series of books. The printer will be digitally printing at 600 dpi in black and white. Images will not exceed 3x5 in. What resolution will yield the best results? Do I need to go to a megapixel camera? Thanks for the help.

-- Don Fogg (dfogg@dfoggknives.com), January 24, 1999

Answers

"600 dpi" in reference to book printing sounds a little odd. Books are usually offset-printed, using "halftones", and a halftone screen of 150-175 lines per inch is typical. Some waterless presses will print to 600 lpi, but that's pretty rare. Check with the printer about what dpi your *files* need to be, and you can figure the necessary camera resolution from there. For instance, a camera with 1024 pixels horizontally would give about 200 dpi at 3x5. The printer may tell you that you need 2 pixels for each halftone dot, but in my experience, a ratio of 1.5 is enough. (In the example above, the 2:1 rule would say your 200 dpi resolution from the camera would only be enough for a 100-line halftone screen. At 1.5:1, you'd be able to use a 133 line screen.) Hope this helps, rather than confuses! Bottom line, ask the printer what *line screen* he's using, as well as what dpi he actually feels he needs. Another bottom line: You should really get a megapixel camera anyway, since anything less is really going to limit you for printed output.

-- Dave Etchells (web@imaging-resource.com), January 24, 1999.

3" x 5" @ 600 dpi = 1800 x 3000 resolution. As the previous answer states however, you should ask your printer what resolution image is needed. it is always a good idea to go over all details of what is needed with your printer.

-- Will Tait (will@nanospace.com), February 01, 1999.