Printing photos question

Discussion in 'Digital Photography' started by jmc, Oct 7, 2007.

  1. jmc

    jmc Guest

    I'm being asked to sell the pics I've been taken at our Western Riding
    Club shows, apparently they're good enough people are actually *asking*
    to pay money for 'em (cool!)

    I show the pics on the club website (cawri.com), at 640x480, which
    provides a decent 4x6 print, and encourage folks to print those images
    for free.

    Now, I've been printing my own photos for years. I just take the
    biggest copy I have, and print that at whatever resolution I need,
    ignoring ppi, which appears to be at 72ppi on my current images
    according to ThumbsPlus. I got decent photos at 8x10, even with my older
    cameras, back to 1.5MP. I've been getting excellent photos with 5MP
    cameras and above, at 8x10.

    Now, I'm looking at something that's explaining resolution vs print
    size, and saying for my 6MP camera the max I can print is 10x6 @300ppi.
    Hmmm.

    My concern is, I'm thinking of providing the digital files rather than
    printing them (that was a big pain last time I did it). I was thinking
    of providing and charging for the files based on the biggest image it
    would print...

    So for example, at 72ppi, I could provide a 1024x768 image intended to
    print an 8x10.

    At 300ppi, I'd have to provide a full-sized 10MP image (3888x2592).

    I don't quite understand the difference, since it appears I've been
    happily printing at the lower ppi for years without loss of quality -
    pictures I've printed have won photo contests, even!

    Can someone help explain this discrepancy? I could use some advice as
    to the best way to provide digital images to my prospective customers,
    that gives them the resolution to print to the size they want, and no
    bigger.

    Or is there a better way I should be doing this?

    Appreciate any advice!

    jmc
     
    jmc, Oct 7, 2007
    #1
    1. Advertising

  2. jmc

    Pete D Guest

    "jmc" <> wrote in message
    news:...
    > I'm being asked to sell the pics I've been taken at our Western Riding
    > Club shows, apparently they're good enough people are actually *asking* to
    > pay money for 'em (cool!)
    >
    > I show the pics on the club website (cawri.com), at 640x480, which
    > provides a decent 4x6 print, and encourage folks to print those images for
    > free.
    >
    > Now, I've been printing my own photos for years. I just take the biggest
    > copy I have, and print that at whatever resolution I need, ignoring ppi,
    > which appears to be at 72ppi on my current images according to ThumbsPlus.
    > I got decent photos at 8x10, even with my older cameras, back to 1.5MP.
    > I've been getting excellent photos with 5MP cameras and above, at 8x10.
    >
    > Now, I'm looking at something that's explaining resolution vs print size,
    > and saying for my 6MP camera the max I can print is 10x6 @300ppi. Hmmm.
    >
    > My concern is, I'm thinking of providing the digital files rather than
    > printing them (that was a big pain last time I did it). I was thinking of
    > providing and charging for the files based on the biggest image it would
    > print...
    >
    > So for example, at 72ppi, I could provide a 1024x768 image intended to
    > print an 8x10.
    >
    > At 300ppi, I'd have to provide a full-sized 10MP image (3888x2592).
    >
    > I don't quite understand the difference, since it appears I've been
    > happily printing at the lower ppi for years without loss of quality -
    > pictures I've printed have won photo contests, even!
    >
    > Can someone help explain this discrepancy? I could use some advice as to
    > the best way to provide digital images to my prospective customers, that
    > gives them the resolution to print to the size they want, and no bigger.
    >
    > Or is there a better way I should be doing this?
    >
    > Appreciate any advice!
    >
    > jmc


    Sorry but I do not see any problem with what you are already doing, if it
    works then keep using the same method.

    If it ain't broken then there is nothing to fix.

    Cheers.

    Pete
     
    Pete D, Oct 7, 2007
    #2
    1. Advertising

  3. "jmc" <> wrote in message
    news:...
    > I'm being asked to sell the pics I've been taken at our Western Riding
    > Club shows, apparently they're good enough people are actually *asking* to
    > pay money for 'em (cool!)

    <snip>
    > Can someone help explain this discrepancy? I could use some advice as to
    > the best way to provide digital images to my prospective customers, that
    > gives them the resolution to print to the size they want, and no bigger.
    >
    > Or is there a better way I should be doing this?
    >
    > Appreciate any advice!
    >

    Have a look here.
    http://www.microsoft.com/windowsxp/using/digitalphotography/learnmore/bestquality.mspx

    http://www.digicamguides.com/print/ppi-print-size.html
     
    /\\BratMan/\\, Oct 7, 2007
    #3
  4. jmc wrote:
    > Now, I've been printing my own photos for years. I just take the
    > biggest copy I have, and print that at whatever resolution I need,
    > ignoring ppi, which appears to be at 72ppi on my current images
    > according to ThumbsPlus. [...]


    > I don't quite understand the difference, since it appears I've
    > been happily printing at the lower ppi for years without loss of
    > quality - pictures I've printed have won photo contests, even!


    No you haven't. You have taken pictures with a certain amount of pixels
    and printing them at a certain physical size. That gives an effective
    ppi that has absolutely nothing to do with whatever ppi is stated in
    the meta-data for the image.

    It's a common mistake: The ppi stated in the image is just a suggestion
    for the print-resolution (and size, when we combine it with the amount
    of pixels). Suggestion being the important word here. You have
    overruled it when you have been printing. Continue doing that and all
    will continue to be fine.
    --
    Toke Eskildsen - http://ekot.dk/
     
    Toke Eskildsen, Oct 7, 2007
    #4
  5. jmc

    Jim Townsend Guest

    jmc wrote:

    > I'm being asked to sell the pics I've been taken at our Western Riding
    > Club shows, apparently they're good enough people are actually *asking*
    > to pay money for 'em (cool!)
    >
    > I show the pics on the club website (cawri.com), at 640x480, which
    > provides a decent 4x6 print, and encourage folks to print those images
    > for free.
    >
    > Now, I've been printing my own photos for years. I just take the
    > biggest copy I have, and print that at whatever resolution I need,
    > ignoring ppi, which appears to be at 72ppi on my current images
    > according to ThumbsPlus. I got decent photos at 8x10, even with my older
    > cameras, back to 1.5MP. I've been getting excellent photos with 5MP
    > cameras and above, at 8x10.
    >
    > Now, I'm looking at something that's explaining resolution vs print
    > size, and saying for my 6MP camera the max I can print is 10x6 @300ppi.
    > Hmmm.



    Pixels per inch is the PRINT resolution, not the image resolution.
    PPI has nothing to do with the quality of a digtial image file.
    The PPI attributed to an image file is meaningless until you actually
    print an image.

    When you print a digital image, you spread the pixels in the image
    across inches of paper. Pixels per inch (PPI) is the number of
    pixels you put on each inch of paper. The formula for calculating
    PPI is:

    Pixels divided by Inches

    So.. If you have an image that's 1000 pixels wide and you print it
    evenly across 10 inches of paper, you printed it at:

    1000 pixels divided by 10 inches of paper = 100 Pixels per inch

    If we print this 1000 pixel image across 5 inches of paper, then we
    get 1000 pixels / 5 inches = 200 Pixels for each inch of paper,
    or in other words 200 PPI.

    You MUST consider inches when dealing with Pixels per INCH because
    you can't have Pixels per inch without inches :) Once you grasp the
    fact that the PPI of an image is nothing more than the PRINT SIZE then
    it all becomes easy :)

    > snip


    > So for example, at 72ppi, I could provide a 1024x768 image intended to
    > print an 8x10.


    No. It's mathematically impossible to spread 1024 pixels across 10 inches
    of paper and have 72 pixels on each of paper.

    If you spread 1024 pixels across 10 inches of paper, you have

    1024 pixels / 10 inches = 102.4 PPI

    Despite the fact that ThumbsPlus said the image has 72 PPI, if you
    print a 1024 pixel image across 10 inches of paper, you actually
    printed it at 102.4 PPI. Whatever software you used to print the
    image CHANGED the PPI from 72 to 102.4.

    This is why the PPI of an image is meaningless. The practical PPI
    doesn't 'happen' until you actually print the image on paper.

    > At 300ppi, I'd have to provide a full-sized 10MP image (3888x2592).


    Again, to provide a 300 PPI image, you need to know the number of
    inches of paper the image will be spread across.

    If you want to print a 10x8 image at 300 PPI, then the image file
    you use MUST be 3000 X 2400 pixels.

    10 inches X 300 PPI = 3000 pixels
    8 inches X 300 PPI = 2400 pixels

    If you want to print a 6 x 4 image at 300 PPI then the image file
    must be 1800 X 1200.
     
    Jim Townsend, Oct 7, 2007
    #5
  6. jmc

    Marvin Guest

    jmc wrote:
    > I'm being asked to sell the pics I've been taken at our Western Riding
    > Club shows, apparently they're good enough people are actually *asking*
    > to pay money for 'em (cool!)
    >
    > I show the pics on the club website (cawri.com), at 640x480, which
    > provides a decent 4x6 print, and encourage folks to print those images
    > for free.
    >
    > Now, I've been printing my own photos for years. I just take the
    > biggest copy I have, and print that at whatever resolution I need,
    > ignoring ppi, which appears to be at 72ppi on my current images
    > according to ThumbsPlus. I got decent photos at 8x10, even with my older
    > cameras, back to 1.5MP. I've been getting excellent photos with 5MP
    > cameras and above, at 8x10.
    >
    > Now, I'm looking at something that's explaining resolution vs print
    > size, and saying for my 6MP camera the max I can print is 10x6 @300ppi.
    > Hmmm.
    >
    > My concern is, I'm thinking of providing the digital files rather than
    > printing them (that was a big pain last time I did it). I was thinking
    > of providing and charging for the files based on the biggest image it
    > would print...
    >
    > So for example, at 72ppi, I could provide a 1024x768 image intended to
    > print an 8x10.
    >
    > At 300ppi, I'd have to provide a full-sized 10MP image (3888x2592).
    >
    > I don't quite understand the difference, since it appears I've been
    > happily printing at the lower ppi for years without loss of quality -
    > pictures I've printed have won photo contests, even!
    >
    > Can someone help explain this discrepancy? I could use some advice as
    > to the best way to provide digital images to my prospective customers,
    > that gives them the resolution to print to the size they want, and no
    > bigger.
    >
    > Or is there a better way I should be doing this?
    >
    > Appreciate any advice!
    >
    > jmc


    Most folks find a print at less than 150 ppi too soft. When
    they buy a print they have already seen, they can't
    complain. If you sell the file, you'll get lots of
    complaints, not only of the lack of sharpness but also about
    other problems, like bad color, when they get prints made at
    drug stores and the like.
     
    Marvin, Oct 7, 2007
    #6
  7. jmc

    Marty Fremen Guest

    jmc <> wrote:
    >
    > I just take the
    > biggest copy I have, and print that at whatever resolution I need,
    > ignoring ppi, which appears to be at 72ppi on my current images
    > according to ThumbsPlus.


    As others have said, the real pixels per inch is determined by big you make
    the print. In a lot of software, when you see the figure "72 dpi" what it
    really means is that the ppi setting in the image file is undefined. The
    72dpi figure which a lot of software defaults to may have had some
    historical significance (e.g. in the days of black & white newspapers I
    think photos used to be printed using a 72dpi dot screen) but is now long
    obsolete.

    As to what is a reasonable resolution, this depends on the image and how
    close you will look at it, but I would consider 100 pixels per inch as the
    minimum. When you printed your 640x480 images at 6x4" you were getting
    107ppi which looks acceptable but is not especially sharp. 100 ppi is fine
    for poster-size prints since they are viewed from some distance, so a
    3000x2000 image can be blown up to 30x20" and look very good. In fact most
    posters made from 35mm negs are unlikely to have more than 100 ppi of
    actual detail in them unless a fine-grained film and tripod was used. And a
    quick look at my local free-sheet reveals that modern all-colour newspapers
    print images with a dot-screen of about 100 dpi. So we can reasonably call
    100ppi "newspaper quality".

    Better for general use is 150ppi, and although still lacking very fine
    detail this is good enough for many purposes. Magazines typically print
    their photos at this resolution. Note though that if you are working
    towards publication, an image destined to be printed at 150dpi should start
    life as twice that, i.e. 300ppi, otherwise the slight mismatch between
    image pixels and printing plate dots will effectively halve the resolution,
    giving poor results. This is one of the reasons why you hear people saying
    your images should be 300ppi. However for direct photographic or inkjet
    printing this should not be a factor and a print from a 150ppi original
    will look as good as a colour magazine photo, in fact probably better.

    The other reason people talk about 300ppi is that this is about the limit
    of human vision when looking at a print from a typical viewing distance
    (which varies according to print size). So for razor sharp images, 300ppi
    is just about perfect, and anything much more than that is likely to be
    wasted, at least in a continuous tone image. Also, traditional photographic
    prints have around 300-400ppi in terms of detail, so you might call 300ppi
    "photo quality".

    As for me, as long as I can print at between 150-300ppi I am happy, though
    I prefer 200ppi upwards if possible. At a pinch 100ppi will do, but in that
    case I usually resample the image to a higher resolution first to avoid
    possible pixellation.
     
    Marty Fremen, Oct 7, 2007
    #7
  8. jmc

    Ron Hunter Guest

    jmc wrote:
    > I'm being asked to sell the pics I've been taken at our Western Riding
    > Club shows, apparently they're good enough people are actually *asking*
    > to pay money for 'em (cool!)
    >
    > I show the pics on the club website (cawri.com), at 640x480, which
    > provides a decent 4x6 print, and encourage folks to print those images
    > for free.
    >
    > Now, I've been printing my own photos for years. I just take the
    > biggest copy I have, and print that at whatever resolution I need,
    > ignoring ppi, which appears to be at 72ppi on my current images
    > according to ThumbsPlus. I got decent photos at 8x10, even with my older
    > cameras, back to 1.5MP. I've been getting excellent photos with 5MP
    > cameras and above, at 8x10.
    >
    > Now, I'm looking at something that's explaining resolution vs print
    > size, and saying for my 6MP camera the max I can print is 10x6 @300ppi.
    > Hmmm.
    >
    > My concern is, I'm thinking of providing the digital files rather than
    > printing them (that was a big pain last time I did it). I was thinking
    > of providing and charging for the files based on the biggest image it
    > would print...
    >
    > So for example, at 72ppi, I could provide a 1024x768 image intended to
    > print an 8x10.
    >
    > At 300ppi, I'd have to provide a full-sized 10MP image (3888x2592).
    >
    > I don't quite understand the difference, since it appears I've been
    > happily printing at the lower ppi for years without loss of quality -
    > pictures I've printed have won photo contests, even!
    >
    > Can someone help explain this discrepancy? I could use some advice as
    > to the best way to provide digital images to my prospective customers,
    > that gives them the resolution to print to the size they want, and no
    > bigger.
    >
    > Or is there a better way I should be doing this?
    >
    > Appreciate any advice!
    >
    > jmc


    The 72ppi you see usually refers to the most common video display
    setting for resolution, and has NOTHING to do with the printing of an
    image. If you have a good monitor, you can change that setting to 96,
    or even 100 or more, and watch Thumbsplus display that new number.

    As for printing, the 'dream number' is 300 pixels/inch, but this is
    often more than is necessary for a good image. Something between 150
    and 250 pixels/inch is usually more than adequate for 4x6, and some
    pictures printed at 8x10 look just fine as low as 150 pixels/inch. I
    would shoot for 200 as a good figure, and just forget about that 72
    figure since it has nothing to do with printing.
     
    Ron Hunter, Oct 8, 2007
    #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. elie
    Replies:
    0
    Views:
    976
  2. elie
    Replies:
    0
    Views:
    896
  3. elie
    Replies:
    0
    Views:
    938
  4. elie
    Replies:
    0
    Views:
    967
  5. elie
    Replies:
    2
    Views:
    790
    shelleyleena
    Nov 27, 2010
Loading...

Share This Page