Image size

Discussion in 'Beyond the Basics' started by chris_arnet, Feb 23, 2008.

  1. chris_arnet

    chris_arnet TPF Noob!

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    Allright. I want to enlarge the photo below as large as possible at 200 dpi. However, i dont know the equation to figuring out how big that can be.
    This is from my 20D and it takes 8,185,344 pixel images. The image is at 3504x2336 at a resolution of 300dpi. Could someone please help me?


    [​IMG]
     
  2. Big Mike

    Big Mike I am Big, I am Mike Staff Member Supporting Member

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    DPI is a printer function.

    I'm sure you mean PPI (pixels per inch) and that is a measure of how big the image is on the screen.

    The size of your image is 3504x2336....the PPI could be 100 or 10,000, it wouldn't really change anything except for the viewing size on the screen.

    Do you want to make a large print? If so, what size?
     
  3. djrichie28

    djrichie28 TPF Noob!

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    17.5"x11.6" Is what those pixel dimensions would be blown up to keeping a 200pixel/inch. This can be done in photoshop. Go into 'Image' then select 'Image Size' and in the resolution box, enter 200 for pixel/inch and make sure you uncheck the 'resample' box. When you enter the new resolution, you will see the image dimensions increase.

    With the resample box unchecked, it will change the size of the image depending on the pixel/inch and with the box checked it will maintain the same size dimensions but change the total pixels.

    All this of course is assumming you mean dpi as pixels/inch. I'm guessing that is what you meant by your question.
     
  4. chris_arnet

    chris_arnet TPF Noob!

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    sorry about that.
    ive never really made a print past 8x10 before so Im not sure how big i could go. Ive heard 200 ppi is the lowest i could go and still have a sharp image. it will be veiwed from one to two feet away, so I can't afford any pixelation at all. what is the lowest you think i coupld go ppi wise?
     
  5. RKW3

    RKW3 TPF Noob!

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    I've gone 150ppi with a 20x30 print, but I don't recommend 150 ppi with anything smaller.

    You should probably stick with 200ppi as your lowest. If you invest in a program like Genuine Fractals you can enlarge your pictures with great quality. Try downloading the demo just to see how it works.
     
  6. Garbz

    Garbz No longer a newbie, moving up!

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    I recommend if you go below 200 dpi to do some upsampling of the image. A 150dpi image upsampled to 300 dpi can look much better than a 150 dpi image itself.
     
  7. djrichie28

    djrichie28 TPF Noob!

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    These are good suggestions. I haven't experimented with them and can't comment, but I'm sure they would work. I have learned though that a good print quality is from 200+ppi.
     
  8. chris_arnet

    chris_arnet TPF Noob!

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    so at 150 dpi, its going to start losing its sharpness, and I will begin to see pixelation?
     
  9. chris_arnet

    chris_arnet TPF Noob!

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    allright, im looking at a 150ppi image (23x15) on my computer, and its perfectly fine image quality. but i see jagged edges (not pixelation), when i zoom in, they go away. is this just something weird that happens on moniters? or will it be like this on my print to? i see it in different smaller sizes as well.
     
  10. djrichie28

    djrichie28 TPF Noob!

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    Monitors display usually at 72dpi. That could be why you see the jagged edges. I had a picture of a Mill roof top on a diagonal and it looked jagged on the screen, but the print was smooth. Don't let the monitor fool you.
     
  11. chris_arnet

    chris_arnet TPF Noob!

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    allright cool.
     

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