7 Replies Latest reply on Oct 14, 2014 4:26 PM by userp123fsd

    Confusing View in LR

    userp123fsd

      I encountered a confusing situation in which LR shows two files differently in its Development module although when zooming-in they look almost the same.

       

      My comparison is between:

      (1) A raw file that was imported and tweaked for contrast, exposure, clarity and sharpening( e.g highlights -100, shadows +100, etc.). A DNG is available here.

      (2) A 16bit tiff file that was generated from the raw file in (1) by exporting the latter. This file was then imported to LR for the sake of this comparison. (I tested TIFF files in sRGB and Pro Photo RGB and the result is pretty much the same)

       

      I expected these two files to look pretty much the same in LR's Development module, but I get a clear difference in the rendering of the highlights.

       

      In the Animated GIF below you can see the differences when both images are unzoomed (i.e. in "Fit" mode in the Navigator panel). The GIF is made out of screen-shots.

      output_G0NAvR.gif

      (notice the brighter leaves in one slide compared to the other)

       

      This difference is quite surprising for me. I don't think that it's a matter of the color space because I tried all options, I suspected that it has something to do with the fact that the TIFF file is only 16bit, while LR probably maintains the developed RAW file in 32bit. However, when zooming-in the files suddenly look quite close. Maybe there is a slight difference, but nothing similar to the 'Fit' view:

      output_F6tLvn.gif

       

      These files are also available here.

       

      Does anyone have an idea what's going on?

      This is particularly confusing because I usually de-fish images like this; so I export to TIFF, de-fish in Hugin, and then import again to LR. I'm relying on LR's Develop module to decide about the exposure settings and now I realize that it's not so reliable in its 'Fit' mode. That's a bit disturbing.

        • 1. Re: Confusing View in LR
          JimHess Adobe Community Professional & MVP

          I have no idea what you are seeing. The two images look identical to me. And, just for your information, Lightroom opens your raw images in a 16 bit workspace, not 32-bit.

          • 2. Re: Confusing View in LR
            THG_BO Level 3

            Hello,

            I downloaded your DNG, exported TIF (ProPhoto), imported tif and compared. I do not see any difference.

             

            Clipboard02.jpg

            • 3. Re: Confusing View in LR
              userp123fsd Level 1

              Thanks THG_BO and JimHess for taking the trouble to check this. I'm writing here a reply to both of you.

               

              I checked it again and I think that I have a better description of the problem: it seems that when viewing an image in a scaled-down view (i.e. not 1:1 but rather 1:4, 1:8, etc.), LR applies some extra sharpening to DNG/RAW files. This makes DNG/RAW files look crisper and slightly brighter in the highlights when viewed scaled-down although they look the same at 1:1.

               

              Here is a screen capture that was taken when the images  are viewed at 1:8:

              1_8_full.png

               

              Do you notice that the DNG is crisper than the TIFF?

               

              Here is a crop from the screen capture:

              1_8_crop.png

              The DNG is clearly crisper - sharper and slightly brighter.

               

              I also compared when viewed at 1:4, here is a screen capture from my desktop:

              1_4_full.png

               

              And here is a crop from this screen capture:

              1_4_crop.png

               

              As you can see, here the difference is less serious.

               

              And if I continued and compared at 1:2 or 1:1 I wouldn't notice any difference - just like you haven't noticed when you compared in a zoomed view of 1:1 probably.

               

               

              To sum up, LR seems to apply some extra sharpening to DNG/RAW files when showing them in a down-scaled view such as 1:4, 1:8, etc. This makes DNG/RAW files look crisper than files in other formats although in 1:1 they look the same.

               

              Do you see the problem I'm describing?

              • 4. Re: Confusing View in LR
                ssprengel Adobe Community Professional & MVP

                I am seeing what you’re seeing, yes.  For reduced-sized views of raws, there is an increase in local contrast that makes the small bright details brighter (sunlit leaves) and the small dark details darker (bare branches against sky).

                 

                I suspect one of two things, the resampling algorithm is starting with different data in the case of raws vs non-raw files, or the algorithm used is more accurate for non-raws due to not having to do so much work to compress the highlights and such. 

                 

                I also don’t remember if demosaicked raw data that is cached in the camera-raw cache is stored as floating point (not 32 vs 16 bit, just floating point vs fixed-bits integers) and that could account for a difference in resampling algorithms.

                 

                In any case, it appears that the resampling of raw files is different than the resampling of non-raw files and that the non-raw files resampling is more accurate.

                • 5. Re: Confusing View in LR
                  THG_BO Level 3

                  Hello,

                   

                  yes you are right. But you are comparing the "wrong" imges. You compare a raw image with a lot of ajustments (which will take place in the moment you look) with an "unprocessed" image.

                  I took you dng, removed all ajustments, saved the tiff and applied the same ajustments on both images. The result is: the TIF looks better to me! (There is a difference in the colors because the vivid camera profile is not there for the Tif. I used Adobe for the DNG and "build in" for the tiff).

                  One addtion: You can not use the library module for pixel peeping. Libraray module works on pre-rendered JPEG images. Colors and sharpness may be different from the develop module.

                  dng_vs_tif.jpg

                  (DNG left, TIF right)

                  • 6. Re: Confusing View in LR
                    userp123fsd Level 1

                    Thanks. I'm thinking in the same directions.

                     

                    But I'm a bit disturbed by this behavior because I usually make my edits when viewing at 1:4 in the Develop module. I wouldn't mind so much about the extra sharpening applied to the DNG file in the 1:4 preview, because I sharpen in 1:1 anyway, but the brighter-crisper small details are misleading. They make the DNG files look better than the exported TIFF/JPEGS look when shared on the web / printed.

                     

                    I noticed this simply because I exported a DNG to TIFF, de-fished it in Hugin, and imported the generated TIFF back. Then I compared them next to each other and noticed that the TIFF is lacking in its micro-contrast. I thought that this was a side-effect of Hugin, but it was simply the fact that in down-scaled view LR shows the DNG with over micro-contrast.

                     

                    EDIT: I meant to say 1:8 in the second paragraph.

                    • 7. Re: Confusing View in LR
                      userp123fsd Level 1

                      I checked this now and I agree that the differences are smaller as less edits are performed to the RAW file.

                       

                      However, I don't think that it helps in anyway to solve the problem because my images are usually heavily processed. And this is plain normal since this is what RAW development is about and this is why LR offers all of these controls - to give the photographer the option to fine tune parameters like brightness, global/micro contrast, tone curve, etc, before generating the file for the output medium. Especially when dealing with images with high dynamic range that require aggressive shadows pushing (up) and highlights pulling (down). As it seems, LR's scaled-down preview of fairly processed RAW files (and only RAW files) results in crisper images and brighter highlights than the TIFFs/JPEGs that it generates. This means that the preview is unreliable in significant properties of the image. I wouldn't mind waiting a second or two for a more accurate preview (or to be requested to press a button and then to wait for the preview to update).