5 Replies Latest reply: May 21, 2013 6:03 AM by LarryHN
dianalevinsmoore Level 1 Level 1 (0 points)

I edit RAW photos and save as Jpeg The dpi reduces from 300 dpi to 72. I have seen an archived discussion saying basically this does not matter. The size of my photo is 3872x2592 for 2.4mb when edited. Unfortunately a newspaper has refused to print a photo as they will only print at 300 dpi.  I have converted this photo back to 300 dpi using preview but apparently 'blowing up the pixels blurs them?  Is there any way I can edit and still maintain 300 dpi?


iMac, Mac OS X (10.7.5), iPad version 5.1.1 iPhone 13G
  • 1. Re: Iphoto converting edited photos from 300 dpi to 72 dpi
    léonie Level 9 Level 9 (51,740 points)

    How did you change the dpi in Preview?

     

    When you adjust the dpi, make sure the pixel size remains the same.

     

    Screen Shot 2013-05-20 at 19.14.03.PNG

    Set the "Fit into" pop-up to "Custom" pixels, and enter the pixels your photo currently has, but change the dpi to 300.

    Your photo will now have smaller dimensions in inches or cm, but still have the same number of pixels and a higher resolution tag.

     

    Regards

    Léonie

  • 2. Re: Iphoto converting edited photos from 300 dpi to 72 dpi
    LarryHN Level 9 Level 9 (56,675 points)

    Yes you can do tat but it akes NO DIFFERENCE - the newspapr has no idea how digital photography works

     

    see http://www.rideau-info.com/photos/mythdpi.html for more details

     

    Simply put no digital file has any DPI (yes there is a DPI field in the EXIF data but it is simply a number and any competent printer simply ignores is since it is meaningless

     

    DPI is dots per inch and therefore can not exist until you have "Inches" - until you print - then DPI is a simple mathmatical calbulation - the dots (pixels) divided by inches (Dots Per Inch)

     

    If you give the newspaper a 3872x2592 file then they can print it up to 12.9066667 Inches x 8.64 inches at 300 DPI (3872/300 x 2592/300)  --  if the print is suppose to be larger than that then you need a higher resolution camera

     

    And although it makes no difference newspapers do not need more than about 120 DPI because of the overall quality of their printing

     

    LN

  • 3. Re: Iphoto converting edited photos from 300 dpi to 72 dpi
    dianalevinsmoore Level 1 Level 1 (0 points)

    Thank you so much for the quick reply.  We did as you suggested up to a certain point. Changing the dpi gave us an enormous size so we reduced it probably by too much. They replied "We appreciate the effort, but with Photoshop changing the DPI reading actually decreases the image quality as the pixels appear blown." We have redone  the image in Preview and kept the size to the original and are waiting to see if this works for them.

  • 4. Re: Iphoto converting edited photos from 300 dpi to 72 dpi
    dianalevinsmoore Level 1 Level 1 (0 points)

    Thank you also,  this was very informative and confirms our belief that the problem is not really ours as we have had full page photos printed using the same camera Nikon D80. This photo was for a tiny print less than 1/16th page so far less than 12.9066667 Inches x 8.64 you mention.

  • 5. Re: Iphoto converting edited photos from 300 dpi to 72 dpi
    LarryHN Level 9 Level 9 (56,675 points)

    Correct - they do not need 300 DPI and your camera is fine for full page photos - although they may not be quiet as sharp as a smaller one - there was a time when newspaper photos were printed at 75 DPI

     

    LN