3 Replies Latest reply on Jul 20, 2017 10:06 PM by WobertC

    Random sized JPEGS


      So i am exporting my images as JPEGS.  The RAW files from my Nikon D810 are big files.  But when i am exporting my JPEGS the size that it produces seem tiny from what they used to be and completely random in size.  All of the images have had only minimal processing, no cropping etc.  When i look at them in Lightroom majority of the sizes are 4732 * 3212 but they export to file sizes of 1 meg or less !  with the occasional file at 14 meg which is what i am used to seeing ?  Also i have one image that i have created 2 virtual copies from - one exports at 14mg one at 1.4mg and one at 1.2mg - for exactly the same images ?


      I have the resized box unchecked.


      Any ideas my friends ?

        • 1. Re: Random sized JPEGS
          F. McLion Adobe Community Professional & MVP

          Please post a screen-capture of your export settings.

          btw: The jpg file size is not a reliable indicator on the quality/size of an image.

          1 person found this helpful
          • 2. Re: Random sized JPEGS
            Per Berntsen Adobe Community Professional

            The jpg format uses lossy compression to reduce file size.

            A low quality setting will create a small file with reduced quality, a high quality setting will create a larger file with little or no apparent loss in quality.


            The other factor that affects file size is image content.

            Images with lots of busy, sharp detail (or noise) do not compress well, and will result in a large file size.

            Images with large flat or smooth areas compress well, and will result in a small file size.

            The difference in file size between your two virtual copies could be due to one having received more sharpening than the other, or that one is noisier than the other. A high Clarity or Dehaze setting could also increase file size.


            As you have seen, the difference in file size can be quite dramatic for images with the same pixel dimensions, and the same quality setting - and this is entirely because of different image content.

            You may find this article useful: File formats


            41 kilobytes, 80 quality


            146 kilobytes, 80 quality

            • 3. Re: Random sized JPEGS
              WobertC Adobe Community Professional

              For a full article on JPG compression - It will answer all the questions on this topic.

              Jeffrey Friedl's Blog » An Analysis of Lightroom JPEG Export Quality Settings

              2 people found this helpful