4 Replies Latest reply: Aug 31, 2007 12:13 PM by (Tony_C_Long) RSS

    Lightroom conversion file sizes are larger than expected

    Ralph Eisenberg Community Member
      The size of my 1Ds2 Raw files when converted into 16-bit psd files seems to double over the usual file sizes (180MB vs 95MB) when using Lightroom 1.1. I'm quite puzzled about what kind of user error and/or ignorance this might be due to, yet even using ACR 4.1, I don't believe that I get this result.
        • 1. Re: Lightroom conversion file sizes are larger than expected
          Jao vdL Community Member
          That camera is 17.2 MP isn't it?, so a 16 bit RGB version of it should be 103 Megabytes divided by about 2 for lossless compression in psd, which comes to about 50-60MB. Are you creating lots of adjustment layers?

          P.S. the original RAW files should be about 15-20MB. I have never seen a file from this camera, so I am just curious.
          • 2. Re: Lightroom conversion file sizes are larger than expected
            Community Member
            Ralph, I also don't see how you would get that file size just from a RAW export.

            I just now did a 16 bit export from a cr2 from my Canon 5D, with 12.8 effective MP. RAW file size about 15 MP. No file size constraint on the export. My psd size is about 74.5MB. I also made a tiff and its' size is about 75.5MP.

            I know your camera has, what, 16.7MP? So your tiff file should, like you say, be in the range of your original 100MB or so. The only settings in export that should significantly affect the file size is the bits per channel (but setting it to 8 bits cuts it by about half) and the Restrain Maximum Size, which would shrink the file if set lower than it's actual resolution. So, unless I'm missing something, I see nothing that would cause it to get twice the size.

            So, I really don't know what would double your file size if your exporting from RAW. Develop settings only add a few KB. I even tried exporting the top image in a stack to see if LR accidentally did something funny like combine the two but no luck!

            Are you sure your not using a PS droplet to double the file size when exporting :)?

            Go through all you settings, and if you find something odd let us know!

            Tony
            • 3. Re: Lightroom conversion file sizes are larger than expected
              Ralph Eisenberg Community Member
              I'm going to be on the road, but before I go I want to be sure to cover all bases. Could you indicate the settings that you feel would be relevant. I want to be sure that I don't miss something. Thanks
              • 4. Re: Lightroom conversion file sizes are larger than expected
                Community Member
                Ralph, I honestly don't know what settings would make your files twice as big as your normal ~100MB! The only ones I know of would make them smaller, i.e. saving as 8 bits or setting the Restrain maximum file size to smaller pixel dimensions.

                So, if this is happening to you all the time, you may want to run it by Adobe for analysis, 'cause I'm pretty mystified.

                Tony