3 Replies Latest reply on Jan 3, 2015 3:32 PM by userp123fsd

    Lightroom 32bit mode for 32bit DNG files

    userp123fsd Level 1

      When I open 32bit (floating point) TIFF files in Lightroom (5.7.1) it opens them as expected - in 32bit mode - and allows me to adjust the exposure slider in the range of -10ev to +10ev.

       

      However, when I open 32bit (floating point) DNG files, it opens them in 16bit mode and allows the exposure slider to range only from -5ev to +5ev.

       

      Does anyone know why it works this way?

      Is there a way to open 32bit DNG files in 32bit mode?


      Note that a 32bit DNG file can be converted to 32bit TIFF using "dng_validate.exe -3 <output.tif> <input.dng>"

      This way I can convert my 32bit DNG files to TIFF, but I lose the control over WB and I end up with huge TIFF files.


      I'm obtaining my 32bit DNG files using HDRMerge. This can be used as a reference:

      https://dl.dropboxusercontent.com/u/21642925/PC211276-211280.dng


      I also tried 32bit DNGs that were created by CeroNoice and I get the same result (LR opens them in 16bit mode rather than 32bit and restricts the exposure slider to -5ev - +5ev).


      It could be that HDRMerge or CeroNoice do not produce the DNG correctly. However, I tried to run the output of HDRMerge through a DNG to DNG conversion using Adobe DNG Converter and it didn't help either.


        • 1. Re: Lightroom 32bit mode for 32bit DNG files
          THG_BO Level 3

          Hello,

           

          same for me with your file. But my 32-bit dng files (converted from tiff) of Photomatix work correctly. I can not find an error in the dng file, but I am not an expert of this file format...

           

          Workaround: You can add an gradulated filter with +4 ev. to to right side of your image - outside the image plane on the gray lightroom background. This will ajust the exposure by +4 for the whole image. You can repeat this process, if needed.

          • 2. Re: Lightroom 32bit mode for 32bit DNG files
            userp123fsd Level 1

            Thanks for taking a look at this.

            I think that converting 32bit tiff files to dng only changes the wrapping. So in a way it's understandable that they are opened in 32bit mode. I still don't understand why normal 32bit dng files can't.

            Thanks for the top about the GND filter. I thought about using a brush all over the frame, but a GND can also be used. I suspect that if LR opens my dng file in 16bit mode than it uses a narrower pipeline for the tone curve and color manipulation so the result will be inferior compared to  a 32bit tiff file (developed with the same settings). That's why I'm trying to find a way to open the dng files directly in 32bit mode.

            • 3. Re: Lightroom 32bit mode for 32bit DNG files
              userp123fsd Level 1

              Does anyone have any idea?