Pixels per inch (20D RAW)??

Discussion in 'Digital Photography' started by Musty, Dec 26, 2004.

  1. Musty

    Musty Guest

    A (hopefully) quick question. I have been playing around with the new Camera
    RAW for CS. It seems to accept my 20D .CR2 files just fine.

    I had a question regarding the pixels-per-inch. When I load my images, it
    says 240 ppi. I can figure out atleast that this number only has meaning in
    regard to print size. The shots are 3504x2336, so 240ppi would say that to
    get an "8MP print" I could use 14.6" x 9.7" paper and no larger.

    I noticed that when I export to another format I can "up" this number. What
    does this really do? I imagine that lowering the 240 number just decreases
    the size of print I can do (without loss of resolution), but I am not sure
    what increasing the # would do.

    Any enlightenment on this would be appreciated.

    Thanks
    Musty.
    Musty, Dec 26, 2004
    #1
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  2. Musty

    Jim Guest

    "Musty" <> wrote in message
    news:QWDzd.6466$...
    > A (hopefully) quick question. I have been playing around with the new

    Camera
    > RAW for CS. It seems to accept my 20D .CR2 files just fine.
    >
    > I had a question regarding the pixels-per-inch. When I load my images, it
    > says 240 ppi. I can figure out atleast that this number only has meaning

    in
    > regard to print size. The shots are 3504x2336, so 240ppi would say that to
    > get an "8MP print" I could use 14.6" x 9.7" paper and no larger.
    >
    > I noticed that when I export to another format I can "up" this number.

    What
    > does this really do? I imagine that lowering the 240 number just decreases
    > the size of print I can do (without loss of resolution), but I am not sure
    > what increasing the # would do.
    >
    > Any enlightenment on this would be appreciated.
    >

    Increasing dpi reduces the size of the image (i.e. the same number of pixels
    spread over a smaller image). Decreasing dpi increases the size of the
    image (i.e. the same number of pixels spread over a larger image). These
    results are correct if you do not change the number of pixels by resampling.
    Jim.
    Jim, Dec 26, 2004
    #2
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  3. Musty

    paul Guest

    Musty wrote:

    > A (hopefully) quick question. I have been playing around with the new Camera
    > RAW for CS. It seems to accept my 20D .CR2 files just fine.
    >
    > I had a question regarding the pixels-per-inch. When I load my images, it
    > says 240 ppi. I can figure out atleast that this number only has meaning in
    > regard to print size. The shots are 3504x2336, so 240ppi would say that to
    > get an "8MP print" I could use 14.6" x 9.7" paper and no larger.
    >
    > I noticed that when I export to another format I can "up" this number. What
    > does this really do? I imagine that lowering the 240 number just decreases
    > the size of print I can do (without loss of resolution), but I am not sure
    > what increasing the # would do.



    240dpi is just their suggestion. You can print it as large as you feel
    it looks good, I did 8-1/2x11 with a 3.3MP digicam at about 190dpi &
    they looked great to my relatively un-picky eyes. I even tried printing
    on six tiled 8x10's (70dpi) & it's not super sharp but I can't see any
    pixels.

    Also, people wont get as close to an 11x17 print as they do with a 4x5.
    paul, Dec 26, 2004
    #3
  4. Musty

    Ryadia Guest

    "Musty" <> wrote in message
    news:QWDzd.6466$...
    > A (hopefully) quick question. I have been playing around with the new

    Camera
    > RAW for CS. It seems to accept my 20D .CR2 files just fine.
    >
    > I had a question regarding the pixels-per-inch. When I load my images, it
    > says 240 ppi. I can figure out atleast that this number only has meaning

    in
    > regard to print size. The shots are 3504x2336, so 240ppi would say that to
    > get an "8MP print" I could use 14.6" x 9.7" paper and no larger.
    >
    > I noticed that when I export to another format I can "up" this number.

    What
    > does this really do? I imagine that lowering the 240 number just decreases
    > the size of print I can do (without loss of resolution), but I am not sure
    > what increasing the # would do.
    >
    > Any enlightenment on this would be appreciated.
    >
    > Thanks
    > Musty.
    >
    >

    When you open a RAW file with Adobe Camera Raw (ACR) you have the
    opportunity to determin the size of the picture. At the bottom of the ACR
    window is the size and dimensions of the image. If you click the down arrow
    next to the boxes with the dimensions, you can choose larger or smaller and
    more or less PPI. Also you can engage in interpolation after you have
    converted the image and produce 24"x36" pictures with as much stunning
    detail as a 4"x6" one. All those knockers -- who even today after
    interpolation is so successful in so many labs - say you can't do it should
    be ignored.

    Yes, it is true that the opened size of a 20D image is about 11"x14" at 300
    ppi. No, this is not the largest size which will produce prints. I scan and
    print film images every day. I also enlarge digital images and make prints
    from them. 35mm (100 ISO) film is claimed to have more ppi detail than a 20D
    file. What these claimers don't tell you because the text books haven't yet
    caught up with the real world... Is that 35mm has to be transformed to
    digital before comparison and it is this transformation which breaks up the
    35mm image with "digital noise" which of course pure digital images don't
    have much of.

    Enjoy your new gear. It doesn't come much better if you have a reliable one!

    Doug
    Ryadia, Dec 26, 2004
    #4
  5. Musty

    Bill Hilton Guest

    >From: "Ryadia"

    > Yes, it is true that the opened size of a 20D image is about 11"x14" at
    > 300 ppi.


    No, it is *not* true, not even close ... the files are 3504 x 2336 pixels ...
    at 300 ppi this is roughly 7.8 x 11.7 inches so you are off by almost 100%.
    Bill Hilton, Dec 26, 2004
    #5
  6. Musty

    Ryadia Guest

    "Bill Hilton" <> wrote in message
    news:...
    > >From: "Ryadia"

    >
    > > Yes, it is true that the opened size of a 20D image is about 11"x14" at
    > > 300 ppi.

    >
    > No, it is *not* true, not even close ... the files are 3504 x 2336 pixels

    ....
    > at 300 ppi this is roughly 7.8 x 11.7 inches so you are off by almost

    100%.
    >
    >
    >

    Get your head out of the text books Bill. We work in the real world now.
    Take a look at the size you can open the file at with the method I
    described.

    Doug
    Ryadia, Dec 27, 2004
    #6
  7. "Musty" <> wrote in
    news:QWDzd.6466$:

    > I noticed that when I export to another format I can "up" this number.
    > What does this really do? I imagine that lowering the 240 number just
    > decreases the size of print I can do (without loss of resolution), but
    > I am not sure what increasing the # would do.
    >


    Nothing happens really. It is just a number.
    The image is still the same. The PPI number is just
    a suggestion about actual print size. So - lower
    and increase it all you want. Nothing will change.

    The only thing you shall be aware of is resizing.
    When you resize, you can also resample, or not.
    If you resample (up or down), then the number of
    pixels will change. If you don't resample - nothing
    happens, except the sugested print size changes.

    Some programs use the suggested print size when printing.
    Photoshop may do so or not - depending on how you print.
    But in most case (IMHO) the suggested print size has no
    value when printing. At least I do always choose the
    print size when actually doing the printing.


    /Roland
    Roland Karlsson, Dec 27, 2004
    #7
  8. Musty

    Bill Hilton Guest

    >>> From: "Ryadia"
    >>
    >>> Yes, it is true that the opened size of a 20D image is about 11"x14"
    >>> at 300 ppi.


    >> "Bill Hilton"
    >>
    >> No, it is *not* true, not even close ... the files are 3504 x 2336 pixels
    >> at 300 ppi this is roughly 7.8 x 11.7 inches so you are off by almost
    >> 100%.


    >From: "Ryadia"
    >
    >Take a look at the size you can open the file at with the method I
    >described.


    Sure, using interpolation ... big deal, you can go all the way to 6,144 x 4,096
    with the RAW converter resize option. If you knew much about Photoshop you'd
    realize it's better to do the resizing outside the RAW converter though.

    Since you were laughed off the Photoshop newsgroup for being so clueless about
    Photoshop I guess you probably didn't know that. Did Interpol ever find the
    people who were tormenting you when you were calling yourself TechnoAussie?
    You said you were going to sic the law on them :)

    >Get your head out of the text books Bill. We work in the real world now.


    So do I, Doug, or Ryadia (glad to see you dropped the lie that "Ryadia" was an
    employee of yours ... such delusion isn't pretty and doesn't fool anyone), or
    TechnoAussie or whatever you are calling yourself today.
    Bill Hilton, Dec 27, 2004
    #8
  9. Musty

    Ryadia Guest

    "Bill Hilton" <> wrote in message
    news:20041227105902.06016.00001648@mb-
    >
    > Sure, using interpolation ... big deal, you can go all the way to 6,144 x

    4,096
    > with the RAW converter resize option. If you knew much about Photoshop

    you'd
    > realize it's better to do the resizing outside the RAW converter though.
    >
    > Since you were laughed off the Photoshop newsgroup for being so clueless

    about
    > Photoshop I guess you probably didn't know that. Did Interpol ever find

    the
    > people who were tormenting you when you were calling yourself

    TechnoAussie?
    > You said you were going to sic the law on them :)
    >
    > >Get your head out of the text books Bill. We work in the real world now.

    >
    > So do I, Doug, or Ryadia (glad to see you dropped the lie that "Ryadia"

    was an
    > employee of yours ... such delusion isn't pretty and doesn't fool anyone),

    or
    > TechnoAussie or whatever you are calling yourself today.
    >

    Why is it Bill, that when someone *anyone* pulls you up for something you
    resort to personal abuse? I guess one day, you will realize that the world
    according to Bill Hilton is a very lonely place.

    Doug
    Ryadia, Dec 27, 2004
    #9
  10. Musty

    Ryadia Guest

    "Bill Hilton" <> wrote in message
    news:...
    >
    > So do I, Doug, or Ryadia (glad to see you dropped the lie that "Ryadia"

    was an
    > employee of yours ... such delusion isn't pretty and doesn't fool anyone),

    or
    > TechnoAussie or whatever you are calling yourself today.
    >
    >

    The day I have to answer to you for using a pre-configured computer in a
    company I own while an employee is on holidays, is the day hell freezes
    over.

    Get a life idiot!
    Ryadia, Dec 27, 2004
    #10
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