10 Replies Latest reply on Nov 12, 2015 7:33 AM by trshaner

    Unsharp-Blurry Pics / Zoom Bug

    Alecx123 Level 1

      Hi

       

      I am having a problem that drives me crazy. The previews of my photos are always slightly blurry or unsharp - however you want to call it.

       

      Now, the strange thing is this:

      If I zoom in it is sharp, when I then zoom out, the photo stays sharp for a split-second and then gets blurry again. It's not day and night, but still very, very annoying. Especially because you see that the picture is sharp, but it just doesn't stay so.

      Another strange behaviour happens in the fullscreen mode. . If I go directly to fullscreen it is also slightly unsharp, but, if I first zoom in in preview mode and then click F for fullscreen and then zoom out, the picture is sharp.

       

      Btw, this happens since LR5 if I recall it right. No matter what computer or what preview size I use(or 1:1). All the usual fixes have been tried (deleted preferences, re-install, clean-install, delete previews, new computer, different graphic-card etc.).

      This must be a bug in LR (scaling/Rendering?) of the image.

       

      I'd be happy to hear if someone else is experiencing this Problem too. You have to look very closely, as I said, it's not a day and night difference.

       

      Cheers

      Alex

        • 1. Re: Unsharp-Blurry Pics / Zoom Bug
          Mrinmay Majhi Adobe Employee

          Hi Alecx,

           

          Could you please check and confirm the version of Lightroom you are using?

          Which operating system are you using?



          ~Mrinmay

          • 2. Re: Unsharp-Blurry Pics / Zoom Bug
            Alecx123 Level 1

            Hi Mrinmay

             

            I am using Lightroom CC and Windows 10, with a brand new i7-6700K, 32GB RAM and a GTX960-2GB.

            But, I had the same happening on a QuadCore 3Ghz, 8GB RAM and Windows Vista and Windows 7. I think this "bug" in LR goes back several versions.

             

            Best,

            Alex

            • 3. Re: Unsharp-Blurry Pics / Zoom Bug
              Dr Tone Level 1

              This particular problem has been in Lightroom for years.  It's been reported in this forum on numerous occasions by numerous people.

               

              I've just learned to live with it, don't get your hopes up that it will be fixed.

              • 4. Re: Unsharp-Blurry Pics / Zoom Bug
                Alecx123 Level 1

                @Dr Tone
                ...that's what I thought. Did Adobe ever make a statement about this? I mean, this is a major thing for a photo editor...

                 

                @Mrinmay
                I just saw that you are staff. Can you tell us more about this specific problem?

                • 5. Re: Unsharp-Blurry Pics / Zoom Bug
                  trshaner Adobe Community Professional & MVP

                  Alecx123 wrote:

                   

                  Hi

                   

                  Now, the strange thing is this:

                  If I zoom in it is sharp, when I then zoom out, the photo stays sharp for a split-second and then gets blurry again. It's not day and night, but still very, very annoying. Especially because you see that the picture is sharp, but it just doesn't stay so.

                  When you change the Zoom view LR initially displays a less-accurate nearest-neighbor interpolation preview. This interpolation algorithm produces "jaggies on edges giving the appearance of higher sharpness. Once the higher-quality preview is rendered onscreen the image may appear to lose sharpness. Download this test image to verify this behavior:

                   

                  http://www.bealecorner.org/red/test-patterns/star-chart-bars-full-600dpi.png

                   

                  The Develop module also uses a less-accurate, but quicker rendering interpolation algorithm. Using the above test image switch between the Library and Develop modules at Fit view. The Develop module should appear slightly sharper (more detail in center area), which is an illusion due to the less accurate stair-stepped rendering. The only 100% accurate view is 1:1 Zoom view.

                  • 6. Re: Unsharp-Blurry Pics / Zoom Bug
                    Alecx123 Level 1

                    trshaner
                    Thanks for your answer. I understand the first part of your post, but that doesn't explain it all to me. I have tested with my own photos and seeing the jaggies on the edges of a cats whiskers made me first think of you beeing 100% right, but then I looked at the cats eyes. They are like glass marbles. I saw no jaggies, but they were definitely sharper. Anyway, that might still be the effect you describe.

                     

                    How do you explain this part of my first post:

                    "Another strange behaviour happens in the fullscreen mode. If I go directly to fullscreen it is also slightly unsharp, but, if I first zoom in in preview mode and then click F for fullscreen and then zoom out, the picture is sharp."

                     

                    Why "no jaggies" if I directly click F and "jaggies" if I do it differently? It's still fullscreen-mode, but the image looks different.

                     

                    I suppose I wish LR would behave a bit more like PS. I can estimate the sharpness of the full picture way better in PS.
                    1:1 zoom is not ideal to check general sharpness.

                    • 7. Re: Unsharp-Blurry Pics / Zoom Bug
                      trshaner Adobe Community Professional & MVP

                      Alecx123 wrote:

                       

                      How do you explain this part of my first post:

                      "Another strange behaviour happens in the fullscreen mode. If I go directly to fullscreen it is also slightly unsharp, but, if I first zoom in in preview mode and then click F for fullscreen and then zoom out, the picture is sharp."

                       

                      Why "no jaggies" if I directly click F and "jaggies" if I do it differently? It's still fullscreen-mode, but the image looks different.

                      Good catch ! I can confirm what you are seeing. Open the below test image, left-click to launch it full-size, right-click, and select 'Save image as' or whatever your browser says and save it to your desktop. Import the test image into LR and do the same full-screen mode test.

                       

                      http://www.bealecorner.org/red/test-patterns/star-chart-bars-full-600dpi.png

                       

                      (Click on image to launch full-size)

                      Fullscreen Test.jpg

                       

                      Here's what I think is happening.

                       

                      1) LR uses the Library Pyramid Previews (1:16, 1:8, 1:4, 1:3, 1:2, 1:1) when in normal-screen mode with an additional interpolation for Fit and Fill Zoom views.

                      2) When full-screen mode is initially entered LR initially uses the Library Pyramid Previews same as above.

                      3) When Zooming to 1:1 view and then back to Fit view in full-screen mode it appears LR only uses a simpler algorithm (nearest neighbor?) that causes the jaggies.

                       

                      This may have been done to improve performance when in full screen mode. For reference I am using LR 2015.1.1 with Windows 7 SP1.

                      • 8. Re: Unsharp-Blurry Pics / Zoom Bug
                        trshaner Adobe Community Professional & MVP

                        I forgot to answer this question:

                        Alecx123 wrote:

                        I suppose I wish LR would behave a bit more like PS. I can estimate the sharpness of the full picture way better in PS.
                        1:1 zoom is not ideal to check general sharpness.

                        Believe it or not LR's Library module Zoom previews are more accurate than PS's. LR uses Library preview files that contain an image pyramid of reduced size images (1:16, 1:8, 1:4,etc.). These Library preview pyramid images are built using high-quality bicubic interpolation, which is the same  algorithm used in LR and PS for resizing images. The bicubic interpolation algorithm takes much longer to process and can't be used in PS's screen view since it doesn't use pre-rendered preview files like LR.

                         

                        When in LR's full-sceen-mode you can return to the more-accurate Fit view preview after 1:1 Zoom by selecting the next image with the arrow keys and then back. It will revert to the higher-quality preview. So you can "estimate sharpness" in full-screen mode at both Fit  and 1:1 view. Just remember the sharper preview with jaggies is an illusion. When in full-screen Fit mode don't click on the image and the Fit view previews will remain accurate.

                         

                        Below is the test image in PS at 16.6% magnification and the Library preview at the same size. I think you'll agree the LR Library preview is more accurate.

                         

                        (Click  on image to see full-size)

                        LR vs PS Fit View Compare.jpg

                        • 9. Re: Unsharp-Blurry Pics / Zoom Bug
                          Alecx123 Level 1

                          Thanks for your elaborated answer. It's very appreciated. I will keep this in mind, when working with LR from now on.

                           

                          Cheers!

                          Alex

                          p.s. in PS I always zoom to 33.3%, 66.6% or 100% to view sharpness.

                          • 10. Re: Unsharp-Blurry Pics / Zoom Bug
                            trshaner Adobe Community Professional & MVP

                            Alecx123 wrote:

                            p.s. in PS I always zoom to 33.3%, 66.6% or 100% to view sharpness.

                            You'll get the most accurate preview in PS using the even number Zoom settings 50% (1:2), 25% (1:4), 12.5% (1:8), etc. Compare the star-chart test image preview in PS at 33.33% versus LR Library module at 1:3. The artifacting is due to the simpler algorithm used in PS. The LR Library module uses high-quality bicubic rendered preview files.

                            (Click on image to see full-size)

                            PS vs LR Zoom View Accuracy.jpg

                            You'll get the most accurate preview using LR's Library module with pyramid Zoom settings 1:16, 1:8, 1:4, 1:3, 1:2 and of course 1:1. This is because those settings use the rendered Library preview without a 2nd interpolation required when using Fit and Fill.

                             

                            SUMMARY

                            In the final analysis it's the quality and sharpness of the Output files we should be most concerned about. This generally includes resizing the image in LR's Export module. When using Image Sizing the Output Sharpening settings have far more impact than the Develop module Sharpening settings (Capture Sharpening). If the Exported image file isn't sharp enough when viewed in the Library module at 1:1 view then try using the 'High' Output Sharpening setting. If still not sharp enough you may need to revisit the Develop module Detail panel. When adjusting the Detail panel controls make sure to use only the 1:1 Zoom view. I think that covers all bases.