5 Replies Latest reply on Jul 18, 2013 12:58 AM by Fuzzy Barsik

    Difference in quality between preview and rendered video

    Kim DT

      I'm new to Premiere Pro CC but I have tried to import some HD video (1080p25) from my Canon 5Dmrk3. When downscaling (Scale to Frame Size) to an SD-timeline I did notice a difference in quality between preview (yellow) and rendered (green) video clips. The yellow clips where downscaled to the expected lower resolution in SD but when I rendered the clips (green) the resolution decreased to as far I could judge to half the resolution or television lines.

       

      I tried to export the sequence to a new file (quicktime, DV50, .mov) but got the same result when importing to Premiere. But when I viewed the file in Quicktime Player the quality was fine.

       

      I have the same problem when I zoom and pan in to large picture files.

       

      What I expected was that the rendered clips should be like the final quality and as it is now it is difficult to work with downscaled video and image clips.

       

       

      Project Settings: Video Rendering and Playback Engine GPU Acceleration (CUDA)

      Export Settings: QuickTime, DV50 PAL

      Use Max. Render Quality, Use Previews

       

      My system:

      MacBook Pro

      OS X 10.8.4 (12E55)

      2.7 GHz Intel Core i7
      16GB 1600MHz DDR3

      NVIDIA GeForce GT 650M 1024 MB

       

      Regards

      Kim Dang Trong

        • 1. Re: Difference in quality between preview and rendered video
          Sausagehead5 Level 1

          I get bad results when working in SD with GPU acceleration turned on, try turning it off when working with SD.

          • 2. Re: Difference in quality between preview and rendered video
            Kim DT Level 1

            Hi Sausagehead5

            Thank You for your reply, but it was not a solution for me. Now my preview (all red clips) is really bad and after rendering I have the same result (lower res playback) and export lasted about 4 times longer. The final file where fine though - viewed i QT player.

             

            Regards Kim DT

            • 3. Re: Difference in quality between preview and rendered video
              Jim_Simon Level 8

              When downscaling (Scale to Frame Size) to an SD-timeline

               

              Don't do that.  Work in a sequence that matches your media, then scale it as needed on export.

               

               

              Use Previews

               

              Don't do that either.  More often than not, the previews will add a generational loss to your export.

              • 4. Re: Difference in quality between preview and rendered video
                Kim DT Level 1

                Hi Jim

                Thank You for your reply. To the first answer: But sometimes I have to, if most of my footage is shot in SD but additional shots come from a DSLR I have to downscale it on the Timeline.

                 

                Second answer: It is a pity if you can't use "Use Preview" because that will extend the Export time, especially on larger and complex projects.

                 

                Could the advice be: If using different formats or zoom and pan in large images on the Timeline, don't render the clips and disable "Use Previews" when exporting to get the highest quality.

                • 5. Re: Difference in quality between preview and rendered video
                  Fuzzy Barsik Level 4
                  Could the advice be: If using different formats or zoom and pan in large images on the Timeline, don't render the clips and disable "Use Previews" when exporting to get the highest quality.

                  If you utilise custom sequence settings with a production codec assigned for rendering previews, you're safe to reuse preview files on final export. However, rendering previews in this case may take much longer compared to when you utilise default sequence presets, where previews exploit MPEG2. So, I would think twice and run some tests in order to decide whether I really want to generate my previews with a production codec.

                  I tried to export the sequence to a new file (quicktime, DV50, .mov) but got the same result when importing to Premiere. But when I viewed the file in Quicktime Player the quality was fine.

                  Check your Playback Resolution settings: with the statement above I would suspect they are set to 1/2.

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