Tiff dpi

Discussion in 'Photography' started by Dirty Harry, Oct 23, 2004.

  1. Dirty Harry

    Dirty Harry Guest

    I have a canon rebel and use the canon software to convert from raw to
    tiff. The default resolution seems to be 96dpi which I've been leaving it
    at. It makes an 18 meg tiff. Should I be changing this to 300dpi if I want
    to take them in to get printed?
     
    Dirty Harry, Oct 23, 2004
    #1
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  2. Dirty Harry

    Petros Guest

    Dirty Harry posted:
    Nope. When you take your file to the lab they use the original file to
    make the print and you decide at what size to print it. Setting dpi in
    a file makes sense only when you're placing an image in a DTP program
    for page layout when printing to an offset printer.
     
    Petros, Oct 23, 2004
    #2
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  3. Dirty Harry

    Stan Guest


    You don't really have to, but most commercial printing requires images
    to be submitted at 300 dpi. They could probably do it themselves, but
    prefer not to have the extra work.

    Photo labs understand the camera defaults, and will probably make the
    necessary adjustments.

    Most desktop printers have drivers that adjust the print size for your
    printed page during the processing of your image. Re sizing it may save
    you some time during printing.

    Some things to keep in mind are two aspects of your file: dpi and print
    size. In Photoshop, if you change a 100 dpi image of 400 pixels by 500
    pixels to 300 dpi, your file becomes 1200 pixels by 1500 pixels. Your
    print size remains the same. Just don't use the resample feature, or
    you will degrade your image.

    Personally, I try to keep all of my tif files at 300 dpi, just as a
    matter of standard.


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    Stan, New Orleans

    http://www.neworleansphotographs.com
    http://www.atneworleans.com
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    Stan, Oct 23, 2004
    #3
  4. Dirty Harry

    Stan Guest



    One more thing, your camera probably has quality settings, which may
    affect image size and dpi.




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    Stan, New Orleans

    http://www.neworleansphotographs.com
    http://www.atneworleans.com
    http://www.sbeckart.com/sbeck
     
    Stan, Oct 23, 2004
    #4
  5. Dirty Harry

    HC Guest

    Some things to keep in mind are two aspects of your file: dpi and print
    How do you changing a 400X500 image to 1200X1500 without resampling it? :)
     
    HC, Oct 23, 2004
    #5
  6. Dirty Harry

    Stan Guest

    Stan, Oct 23, 2004
    #6
  7. Dirty Harry

    Carl Guest

    Resampling re-interpolates the image - which you should avoid allowing
    Photoshop to do, unless you don't care about image quality, of course.
     
    Carl, Oct 23, 2004
    #7
  8. Dirty Harry

    Bri. Guest

    In Carl typed...
    May I ask the same question?
    How do you convert 400 x 500 [200,000 pixels]
    to 1200 x 1500 [1,800,000 pixels]
    without interpolation?
     
    Bri., Oct 23, 2004
    #8
  9. Dirty Harry

    Carl Guest

    In Photoshop, Select Image from the menu bar and Image size from the
    menu. The bottom check box in the dialogue that opens is automatically
    ticked for re sampling. Uncheck it.

    Re-sizing an image does not require re sampling or interpolation. When a
    raster image is resized then pixels are either removed (to reduce image
    size) or added (to increase). Re sampling and Interpolation are
    intelligent software processes designed to reduce the gappy effect (when
    reducing an image size) or the Jacob's ladder effect created when
    increasing.

    Unfortunately Photoshop employs a Bicubic process which is not
    particularly good. Ideally you should use software for re sampling and
    interpolating that employs Lanczos algorithms. This will ensure that the
    image retains the maximum quality that is possible when resizing an
    image. Personally, I use Qimage for this and for its print templates,
    but there are other applications that will do the job well.
     
    Carl, Oct 23, 2004
    #9
  10. Dirty Harry

    HC Guest

    May I ask the same question?
    I think this still producing a 400 x 500 pixel image :)
     
    HC, Oct 23, 2004
    #10
  11. Dirty Harry

    Petros Guest

    Carl posted:
    Two things: 1) IrfanView has the Lanczos filter for free and 2) this
    thread is so long because HC made a mistake which some picked up on and
    some did not. You can't take a 400x500 pixel image and make it
    1200x1500 without resampling it in photoshop or any other program. You
    can change the dpi and therefore the size that it prints at, though...
     
    Petros, Oct 23, 2004
    #11
  12. Dirty Harry

    HC Guest

    Exactly when did I say this was possible?
     
    HC, Oct 23, 2004
    #12
  13. Dirty Harry

    Petros Guest

    HC posted:
    You didn't, Carl did, as I quoted in my response.
     
    Petros, Oct 23, 2004
    #13
  14. Dirty Harry

    Carl Guest

    1) agreed. XnView is much the same and also free.
    2) Also agreed. There was a typo on my part and I added a "does not"
    instead of a "does" in the sentence. That will teach me not to check
    what I write before I send. As it stands my second paragraph makes no sense.
     
    Carl, Oct 23, 2004
    #14
  15. Dirty Harry

    ian green Guest

    warning warning
    this is the very moment to claim for longest thread
    go on please

    --

    ?? ???? / ian green

    Xeto : photographic project
    ???? : ??????????
    http://xeto.front.ru
    ..
    EOF

     
    ian green, Oct 23, 2004
    #15
  16. Dirty Harry

    Petros Guest

    Carl posted:
    No problem :) I just didn't want any newbies to get confused, since it
    seems that dpi and image size is one of the most confusing concepts for
    a large number of folks.
     
    Petros, Oct 23, 2004
    #16
  17. Dirty Harry

    Dirty Harry Guest

    hehe yea! But I am getting some good info so please keep talking ppl!
    Thanks again!


    --
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    Sign my guestbook if you like what you saw ;-)





     
    Dirty Harry, Oct 24, 2004
    #17
  18. Dirty Harry

    Dirty Harry Guest

    Ok I took an 18 meg tiff into blacks today. The file was like 20 inches by
    something at 96 dpi, i told them to make me an 8x12 with it...shall see what
    happens...
     
    Dirty Harry, Oct 24, 2004
    #18
  19. Dirty Harry

    Dirty Harry Guest

    Hmmm the picture was 7.75x12 but they made it 8 inches somehow...So they
    messed with my image! Bah...
     
    Dirty Harry, Oct 27, 2004
    #19
  20. Dirty Harry

    RicSeyler Guest

    Even those fractal programs don't retain the chrispness of the original.
    Once you downsample there is no real way to get the data back in it's
    original quality.. I've used Genuine Fractals 3.5 and it didn't do much
    better
    than PhotoShop 7's new "resize image" command....

    The poster's best bet is to keep the large pic size (dimension) THEN
    upsample the DPI and see what the finished pic's dimension ends up being.
    It might be large enough for his project if he's using a high enough
    megapixel camera set to the finest setting.

    Carl wrote:
     
    RicSeyler, Oct 27, 2004
    #20
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