scanning dpi 9600 vs 4800

Discussion in 'Digital Photography' started by out of the loop, May 12, 2009.

  1. out of the loop macrumors newbie

    May 12, 2009
    looking at purchasing a hp photosmart. Can someone please tell me if there is a noticeable difference between a scanner that has an optical of up to 4800 verses 9600. Visually is there a difference on photos or will I simply just get a larger file size?
  2. Macky-Mac macrumors 68030


    May 18, 2004
    you're talking about photos? like 4x6 snapshots? And you're going to print them at the same size? that's assuming you're going to print them at all...... generally "most" people aren't going to have a need to scan at either of those high resolutions.

    There's a limit to the amount of detail your eye can see. 300 to 600 dpi seems to be the general recommendation for photos you're apt to print at the same size or enlarge just a bit.
  3. anubis macrumors 6502a

    Feb 7, 2003
    Maximum human visual acuity is about 1 arc minute. With perfect vision, looking at something 2 feet in front of your face, and taking into account Nyquist sampling, the maximum possible amount of visual information you can see is about 300 dpi. Unless you plan on scanning a 4x6 and blowing it up to life size, you're just wasting space by scanning at those resolutions.
  4. out of the loop thread starter macrumors newbie

    May 12, 2009
    Thanks. good info. this is what I thought but wanted to check.
  5. OreoCookie macrumors 68030

    Apr 14, 2001
    Sendai, Japan
    Unless you're scanning hand-printed pictures, there will be zero difference. Photos are commercially printed at 300 dpi, on rare occasions you can see photo printers with 400 dpi. That has little to do with the 9600 dpi current inkjets can do, because they need many pixels to mix colors.

    A typical 4x6 print has 2-3 megapixels worth of information. Scanning printed pictures at anything beyond, say, 600 dpi is a waste of space, energy and time.

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