Skip to main content
winegardeng55249505
winegardeng55249505
Participating Frequently
October 4, 2018
Answered

Export ppi and File Size

  • October 4, 2018
  • 3 replies
  • 3090 views

Something that I am having trouble getting my head around.  When exporting, some say that, if you do not click the Resize to Fit box, then the ppi setting has little or no effect on the exported file (kind of makes sense as the export process does not know what size print you want).  But, I did a couple of tests where I exported the same photo using 3 different ppi settings (200, 300, 360).  In each case, when I examine the jpg, in Windows, they all show as having dimensions of 5083 x 3389.  But when I examine the actual file size, I see 21.2, 21.9 and  22.4 MB.  To me, this just confuses the issue.

What I am looking for is the best values to use so that whatever size print I choose to have made will be the best.

Can someone please help me clear this up?

    This topic has been closed for replies.
    Correct answer richardplondon

    One reason for seeing slightly different file size from selecting different PPI settings, other things being equal, may be if you have got output sharpening active. Specifically, if this output sharpening is set to either "gloss" or "matt" output.

    A PPI setting denotes some sort of implied physical scale; and output sharpening with a print intent does take account of physical scale in its calculations (though it will not, AFAICT, with a "screen" intent... which seems to only pay attention to the pixel resampling).

    3 replies

    R
    Community Expert
    richardplondonCommunity ExpertCorrect answer
    Community Expert
    October 4, 2018

    One reason for seeing slightly different file size from selecting different PPI settings, other things being equal, may be if you have got output sharpening active. Specifically, if this output sharpening is set to either "gloss" or "matt" output.

    A PPI setting denotes some sort of implied physical scale; and output sharpening with a print intent does take account of physical scale in its calculations (though it will not, AFAICT, with a "screen" intent... which seems to only pay attention to the pixel resampling).

      winegardeng55249505
      winegardeng55249505Author
      Participating Frequently
      October 4, 2018

      In all 3 cases, the only change, to the export dialogue, was the ppi.

      To all.  Thanks for the responses.

      johnrellis
      johnrellis
      Legend
      October 4, 2018

      In all 3 cases, the only change, to the export dialogue, was the ppi.

      Richard explained the likely cause -- you've got the export option Output Sharpening enabled for Glossy or Matte paper.

      I just exported three JPEGs from the same photo with Sharpen For: Matte Paper and observed differing sizes for different PPIs:

      PPI 200: 12.00 MB

      PPI 300: 12.47 MB (4.0% bigger)

      PPI 360: 12.61 MB (5.1% bigger)

      The increases in size are comparable to what you observed.

      I never knew of this behavior before! It throws another wrinkle in the the typical FAQ response that "PPI doesn't matter".

      JP Hess
      JP Hess
      Inspiring
      October 4, 2018

      I find it curious that you are seeing any difference in size at all. I just exported a NEF file as a JPEG, full-sized, one at 72 PPI and one at 300 PPI, At 100% quality. Both copies exported at 11 MB. My experience with changing the PPI has always been that it has had absolutely no impact on the size of the image. For me, I have always found that regardless of what the PPI setting is, the file dimensions are always the same. In this instance, the dimensions are 6000 x 4000 pixels, and changing the PPI isn't going to change those dimensions at all. At least that's the way it has always worked for me.

      winegardeng55249505
      winegardeng55249505Author
      Participating Frequently
      October 4, 2018

      Well, as I indicated, in my case, there are small differences.  I cannot see why.

      JohanElzenga
      Community Expert
      JohanElzengaCommunity Expert
      Community Expert
      October 4, 2018

      There should be no effect at all. Three different ppi settings for the same photo should lead to three identical images.

      -- Johan W. Elzenga
      winegardeng55249505
      winegardeng55249505Author
      Participating Frequently
      October 4, 2018

      Agreed, and yet.....

      Terms & ConditionsAccessibility statement
      Using the community Terms of use Privacy Cookie preferences Do not sell or share my personal information ad choicesAdChoices