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100% crop

Discussion in 'Image Processing' started by Mal, Aug 16, 2011.

  1. Mal

    Mal SC Veteran

    275
    Sep 23, 2010
    Liverpool / UK
    Has anyone got a definitive answer on what is meant by '100% crop'.

    I've been on the blog sites and it seems to mean different things to different people...:mad:
     
  2. Streetshooter

    Streetshooter Administrator Emeritus

    Jul 12, 2010
    Philly, Pa
    It usually but not always means, taking a crop out of the image at it's actual size.
    So maybe you take a 4" x 6" crop out of a 12 " x !8" image. just an example, not accurate for the guys that will hang me...

    When you process an image, you should see the ACTUAL size according to the pixels. That's the size that a 100% crop comes from.

    I hope this is ambiguously definitive....
     
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  3. kyteflyer

    kyteflyer ~@¿@~

    Jan 31, 2011
    Newcastle, Australia
    Sue
    I'd agree with Don. 100% crop is often used to show off a particular part of an image at its actual size. Some of us don't do it often, because it can also show off the shortcomings of the shot :)

    Examples (bad shots to begin with but its just as a demo)
    1) a hideous pen with a butterfly on it, that was given to me a couple of years ago.
    [​IMG]
    2) a 100% crop of part of the butterfly, which shows just how bad the shot is.
    [​IMG]
     
    • Like Like x 3
  4. Luckypenguin

    Luckypenguin SC Hall of Famer

    Dec 24, 2010
    Brisbane, Australia
    Nic
    100% crop should be a part of an image that has not been resized. For example, take a 500x500 square from an image and display it on the Internet at 500x500 pixels = 100% crop.

    It is basically porn for pixel peepers, as in;

    Oooh, check out my moire patterns,
    Your high ISO noise is so silky smooth, and
    Your CA is so hot right now.
     
    • Like Like x 4
  5. Mal

    Mal SC Veteran

    275
    Sep 23, 2010
    Liverpool / UK
    100% image crop

    Assuming that Picasa compresses images to the same resolution.... is this what you mean???

    Image 'A' taken at wide angle (24mm) on my Canon SX30 IS (Derwent Water... all images handheld, and unedited, except for cropping)
    .

    Image size / width 4320 pixels x height 3240 pixels with a resolution of 72 pix/inch
    .
    Image 'B' - zooming in to the 35x (840mm) optical zoom
    .

    ONCE AGAIN - Image size / width 4320 pixels x height 3240 pixels with a resolution of 72 pix/inch
    .
    Now here we go.... If I select an area to crop on image 'B'...
    .

    .
    If I then crop and resize the image to match the same dimensions of the original image... is THIS what you mean by 100% Crop ???
    .

    ONCE AGAIN - Image size / width 4320 pixels x height 3240 pixels with a resolution of 72 pix/inch
     
  6. bartjeej

    bartjeej SC Hall of Famer

    Nov 12, 2010
    bart
    resizing to the size of the original isn't necessary. your crop seems to contain about 1/3rd of the original image horizontally and vertically, so that would make the cropped file (without resizing) around 1440 by 1080 pixels. If you would now post / view this file as a 1440 by 1080 picture, so that each pixel in the file is represented by 1 pixel on the screen, that's a 100% crop.

    If you would size your crop up to the 4320 x 3240 size of the original photo, then every pixel in the file would be represented by 9 pixels on the screen (3 horizontal by 3 vertical), which would be pointless since it's not getting you any additional detail.

    Also, posting / viewing the 4320 x 3240 pixel file as a 4320 x 3240 photo would be a 100% view (which would almost certainly require scrolling around to see all of the image, unless you have some ridiculously high-res screen).
     
    • Like Like x 1
  7. HeatherTheVet

    HeatherTheVet SC All-Pro

    Apr 23, 2011
    Scotland
    Heather
    My brain hurts. I might just go back to LuckyPenguin's pixelated porn.
     
    • Like Like x 2
  8. Mal

    Mal SC Veteran

    275
    Sep 23, 2010
    Liverpool / UK
    Bartjeej...

    Now like heather my brain is starting to hurt..... :wink: If we follow this to a logical conclusion, in order for me to produce a 100% crop for YOU.... I would have to know the resolution of YOUR screen.... and likewise for other members, so a one size fits all (so to speak) cannot be an option open to the 'croppee'..... :confused:
     
  9. kyteflyer

    kyteflyer ~@¿@~

    Jan 31, 2011
    Newcastle, Australia
    Sue
    Mal, you don't need to do anything to the original shot. Take whatever came out of the camera, and then use a selection tool to select an area of 500x500...or even 400x400...it doesn't really matter. Crop to that selection and then view it at full size. That is your 100% crop. There's no requirement for resizing except if you wanted to show the original here in which case you need to resize that to the usual 1024 on longest, or less. But you do the 100% crop before any resizing, and you don't resize the crop. Listen to the lucky penguin :)

    As stated, its for pixel peepers. I've done it once, when I used an elderly Rokkor lens with my K200D, to show someone how well it was working (all of which reminds me, I really must break it out again and try it with the K-5)
     
    • Like Like x 1
  10. AzPete

    AzPete SC Veteran

    404
    Dec 24, 2010
    OMG, this is way to deep for me :smile:

    Hey Bill, pour me a cold one, Im coming over.....
     
    • Like Like x 1
  11. Mal

    Mal SC Veteran

    275
    Sep 23, 2010
    Liverpool / UK
    The mist clears..... Don't think I'll be using this for anything meaningful... but its nice to know...

    Thanks for all the info :yahoo: