300 dpi for online photo printing - to resample in photoshop or not?

Discussion in 'Digital Photography' started by leehoffman@gmail.com, Apr 28, 2006.

  1. Guest

    I have an 8.2 megapixel digital SLR that takes 3456x2304 pixel images.
    When you open these images in photoshop, you have an 48x32 inch image
    at 72 ppi. This is great for onscreen viewing, but not for printing.
    When you resize the image in photoshop, you can keep the ppi above 300
    for the following sizes: 4x6, 5x7, and 8x10. Once you go larger than
    that, the resolution falls below 300. I have been told that you need
    at least 300dpi for making a high quality print, is that right?

    So, if you want to make larger prints, then you have two options.
    Which one do you guys think is better?

    1. turn OFF resampling in photoshop and resize the image, letting the
    resolution fall depending on the size. (ie 11x14 = 172 ppi, 16x20=172
    ppi, and 20x30=115ppi)

    2. turn ON resampling (bicubic) and fix the resolution at 300ppi. This
    means the computer is interpolating and adding pixels to your photo.

    I am curious to find out if anyone has actually made 2 prints of the
    same image at with each method and compared the results? What did you
    find out?
    Thanks very much
    Lee
     
    , Apr 28, 2006
    #1
    1. Advertising

  2. Roy G Guest

    <> wrote in message
    news:...
    >I have an 8.2 megapixel digital SLR that takes 3456x2304 pixel images.
    > When you open these images in photoshop, you have an 48x32 inch image
    > at 72 ppi. This is great for onscreen viewing, but not for printing.
    > When you resize the image in photoshop, you can keep the ppi above 300
    > for the following sizes: 4x6, 5x7, and 8x10. Once you go larger than
    > that, the resolution falls below 300. I have been told that you need
    > at least 300dpi for making a high quality print, is that right?
    >
    > So, if you want to make larger prints, then you have two options.
    > Which one do you guys think is better?
    >
    > 1. turn OFF resampling in photoshop and resize the image, letting the
    > resolution fall depending on the size. (ie 11x14 = 172 ppi, 16x20=172
    > ppi, and 20x30=115ppi)
    >
    > 2. turn ON resampling (bicubic) and fix the resolution at 300ppi. This
    > means the computer is interpolating and adding pixels to your photo.
    >
    > I am curious to find out if anyone has actually made 2 prints of the
    > same image at with each method and compared the results? What did you
    > find out?
    > Thanks very much
    > Lee



    I think you need to turn on your calculator.

    3456(pixels) divided by 12 (inches) gives 288 Ppi.

    So you can print at 12 x 8 inches (your 3 to 2 format) and still get a good
    quality print.

    If you want a print which is 10 inches wide, then the uncropped length for
    calculations, becomes 15 inches and produces a figure of 230 Ppi which will
    still produce a good print.

    Roy G
     
    Roy G, Apr 28, 2006
    #2
    1. Advertising

  3. Guest

    Thanks Roy for your sarcastic jab, that helps a lot. I am not making
    the numbers up, that's what PHOTOSHOP tells you when you bring up the
    "image size" dialog box for a 3456x2304 photo.


    Roy G wrote:
    > <> wrote in message
    > news:...
    > >I have an 8.2 megapixel digital SLR that takes 3456x2304 pixel images.
    > > When you open these images in photoshop, you have an 48x32 inch image
    > > at 72 ppi. This is great for onscreen viewing, but not for printing.
    > > When you resize the image in photoshop, you can keep the ppi above 300
    > > for the following sizes: 4x6, 5x7, and 8x10. Once you go larger than
    > > that, the resolution falls below 300. I have been told that you need
    > > at least 300dpi for making a high quality print, is that right?
    > >
    > > So, if you want to make larger prints, then you have two options.
    > > Which one do you guys think is better?
    > >
    > > 1. turn OFF resampling in photoshop and resize the image, letting the
    > > resolution fall depending on the size. (ie 11x14 = 172 ppi, 16x20=172
    > > ppi, and 20x30=115ppi)
    > >
    > > 2. turn ON resampling (bicubic) and fix the resolution at 300ppi. This
    > > means the computer is interpolating and adding pixels to your photo.
    > >
    > > I am curious to find out if anyone has actually made 2 prints of the
    > > same image at with each method and compared the results? What did you
    > > find out?
    > > Thanks very much
    > > Lee

    >
    >
    > I think you need to turn on your calculator.
    >
    > 3456(pixels) divided by 12 (inches) gives 288 Ppi.
    >
    > So you can print at 12 x 8 inches (your 3 to 2 format) and still get a good
    > quality print.
    >
    > If you want a print which is 10 inches wide, then the uncropped length for
    > calculations, becomes 15 inches and produces a figure of 230 Ppi which will
    > still produce a good print.
    >
    > Roy G
     
    , Apr 29, 2006
    #3
  4. Guest

    yes, that's correct, I typed the wrong number in. An 11x14 is 246 ppi.
    Thanks for the sarcastic jab, that is real helpful. Anyway, it is
    beside the point and doesn't asnwer my question at all. Has anyone
    tried these two and compared them side by side? I'd like to avoid
    ordering a bunch of prints just to compare them when I could learn from
    somebody elses experience. Thank you very much.
    Lee
     
    , Apr 29, 2006
    #4
  5. Wayne Guest

    In article <>,
    says...
    >
    >
    >yes, that's correct, I typed the wrong number in. An 11x14 is 246 ppi.
    > Thanks for the sarcastic jab, that is real helpful. Anyway, it is
    >beside the point and doesn't asnwer my question at all. Has anyone
    >tried these two and compared them side by side? I'd like to avoid
    >ordering a bunch of prints just to compare them when I could learn from
    >somebody elses experience. Thank you very much.
    >Lee



    You think that was sarcasm? It seemed really gentle to me.

    This is sarcasm: If we learned from your computing example, look where
    we'd be. :) Sometimes we need to do our own tests. Dont believe
    everything you hear online.
     
    Wayne, Apr 29, 2006
    #5
  6. Roy G Guest

    <> wrote in message
    news:...
    > Thanks Roy for your sarcastic jab, that helps a lot. I am not making
    > the numbers up, that's what PHOTOSHOP tells you when you bring up the
    > "image size" dialog box for a 3456x2304 photo.
    >
    >
    > Roy G wrote:
    >> <> wrote in message
    >> news:...
    >> >I have an 8.2 megapixel digital SLR that takes 3456x2304 pixel images.
    >> > When you open these images in photoshop, you have an 48x32 inch image
    >> > at 72 ppi. This is great for onscreen viewing, but not for printing.
    >> > When you resize the image in photoshop, you can keep the ppi above 300
    >> > for the following sizes: 4x6, 5x7, and 8x10. Once you go larger than
    >> > that, the resolution falls below 300. I have been told that you need
    >> > at least 300dpi for making a high quality print, is that right?
    >> >
    >> > So, if you want to make larger prints, then you have two options.
    >> > Which one do you guys think is better?
    >> >
    >> > 1. turn OFF resampling in photoshop and resize the image, letting the
    >> > resolution fall depending on the size. (ie 11x14 = 172 ppi, 16x20=172
    >> > ppi, and 20x30=115ppi)
    >> >
    >> > 2. turn ON resampling (bicubic) and fix the resolution at 300ppi. This
    >> > means the computer is interpolating and adding pixels to your photo.
    >> >
    >> > I am curious to find out if anyone has actually made 2 prints of the
    >> > same image at with each method and compared the results? What did you
    >> > find out?
    >> > Thanks very much
    >> > Lee

    >>
    >>
    >> I think you need to turn on your calculator.
    >>
    >> 3456(pixels) divided by 12 (inches) gives 288 Ppi.
    >>
    >> So you can print at 12 x 8 inches (your 3 to 2 format) and still get a
    >> good
    >> quality print.
    >>
    >> If you want a print which is 10 inches wide, then the uncropped length
    >> for
    >> calculations, becomes 15 inches and produces a figure of 230 Ppi which
    >> will
    >> still produce a good print.
    >>
    >> Roy G


    Hoi Mate.

    Don't be so bloody sensitive.

    I wasn't being sarcastic, not even trying. It was very obvious at first
    glance, even before I reached for my calculator, that your figures were well
    out.

    If they were accurate, no-one would have been able to produce 16 x 12s until
    very recently, when the 10 & 12 Mp consumer DSLRs were released.

    I know that given the right subject, I can make a print up to about 18
    inches wide from my 6Mp D70. And they have never yet been criticised for
    poor Print Quality.

    As for your tests, you really need to do that for yourself. You can not
    rely upon other peoples opinion as to what is best. What could be Ok to
    them, could be anything but Ok to you or to me.

    Roy G
     
    Roy G, Apr 29, 2006
    #6
  7. Jim Townsend Guest

    wrote:

    > I have an 8.2 megapixel digital SLR that takes 3456x2304 pixel images.
    > When you open these images in photoshop, you have an 48x32 inch image
    > at 72 ppi. This is great for onscreen viewing, but not for printing.


    72 PPI has absolutely nothing to do with onscreen viewing.

    Your images will look exactly the same at 10 PPI, 100 PPI or 1000 PPI.
    For monitors, it's only the number of pixels in each dimension that count.
    PPI is meaningless.
     
    Jim Townsend, Apr 29, 2006
    #7
  8. Paul J Gans Guest

    Jim Townsend <> wrote:
    > wrote:


    >> I have an 8.2 megapixel digital SLR that takes 3456x2304 pixel images.
    >> When you open these images in photoshop, you have an 48x32 inch image
    >> at 72 ppi. This is great for onscreen viewing, but not for printing.


    >72 PPI has absolutely nothing to do with onscreen viewing.


    >Your images will look exactly the same at 10 PPI, 100 PPI or 1000 PPI.
    >For monitors, it's only the number of pixels in each dimension that count.
    >PPI is meaningless.


    Agreed.

    This sort of thing causes a lot of confusion. The "typical" monitor
    these days runs about 96 ppi. Programs still pretend that they
    are 72 ppi. The difference is that the image will be different
    physical sizes on screen depending on the screen resolution

    One can measure that by simply laying out a suitable line in
    Photoshop or whatever that is, say 200 pixels long. Then display
    it on your monitor and measure the actual length. The actual
    display pixels per inch is then 200 pixels divided by your
    measured length.

    This has NOTHING to do with the size of the image when printed.
    For that one has to understand the arcana of printer drivers.
    I don't, since the details seem to vary from one driver to
    another.

    Often the driver will allow you to pick a size in inches for
    the print. And it will deliver that size. Obviously the driver
    is either shrinking or expanding your image to suit its physical
    needs. I hate that. But I rarely see the native resolution of
    a printer given in either the manual (ha!) or the software.

    So in the end I end up wasting ink while I find the right number
    of pixels to feed the printer to get a decent print. I suspect
    that if I had a higher-end printer I'd have less trouble. But
    then, as I said at the start, I don't understand printer drivers.

    ----- Paul J. Gans
     
    Paul J Gans, Apr 30, 2006
    #8
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. DS

    Should File DPI Match Printer DPI?

    DS, Jul 5, 2004, in forum: Digital Photography
    Replies:
    8
    Views:
    646
  2. Boooger

    96 dpi x 96 dpi?

    Boooger, Nov 29, 2005, in forum: Digital Photography
    Replies:
    8
    Views:
    2,635
    Bill Hilton
    Nov 29, 2005
  3. elie
    Replies:
    0
    Views:
    1,022
  4. elie
    Replies:
    0
    Views:
    935
  5. Giuen
    Replies:
    0
    Views:
    1,266
    Giuen
    Sep 12, 2008
Loading...

Share This Page