8 Replies Latest reply on Jul 17, 2013 1:55 PM by Steven L. Gotz

    Previews and Renders

    Sausagehead5 Level 1

      So, all the documentation tells me never to use previews when exporting because it will degrade quality.

       

      My previews are always set either to Uncompressed 10 bit or ProRez HQ, so is Premiere somehow down-rezing my footage on export to lower than either of those codecs???

       

      Seems strange to me to claim "never use previews when exporting" when it all depends on how you have your preview settings set.

        • 1. Re: Previews and Renders
          Sausagehead5 Level 1

          From the documentation:

           

          Rendering of previews is only for preview purposes. Preview files will not be used for final output unless you have Use Previews option checked on output—which you should not use except in the case of rough previews. Using preview files for final output will in almost all cases cause a decrease in quality. It can speed things up in some cases, so it may be useful for creating a rough preview in less time

          • 2. Re: Previews and Renders
            Sausagehead5 Level 1

            Does use Max bit depth, and Max render quality actually do anything in CS6?

            • 3. Re: Previews and Renders
              Steven L. Gotz Level 5

              There are times when previews are helpful. When editing DV-AVI they work just fine since they use the exact same codec.

               

              If you are careful, and your preview codec is of a high quality, and if you ensure that the frame size is appropriate, then it won't hurt anything. But that is so many "IFs" that it is easier to say "don't do it".

              • 4. Re: Previews and Renders
                Sausagehead5 Level 1

                Most all of the material I work with is either 10 Bit DPX or Arri Alexa ProRezHQ. I'm a finish editor and work full rez start to finish.

                 

                 

                When Exporting I always check "match sequence settings" and "use previews", as I stated above my renders are always set to 10 bit uncompressed or ProRezHQ.......So I guess I'm good.....right????

                • 5. Re: Previews and Renders
                  Steven L. Gotz Level 5

                  Probably.

                   

                  Check the frame size of the render files, just in case. I am not at my editing PC, but I recall that mine often (sometimes? always?) use a preview file at 1/4 of the size of my 1920X1080 frame (960X540).

                  • 6. Re: Previews and Renders
                    Sausagehead5 Level 1

                    The preview files DO match the render settings of either uncompressed or ProrezHQ.

                     

                    I guess the documentation is a little misleading, or confusing.

                    • 7. Re: Previews and Renders
                      Fuzzy Barsik Level 4
                      I guess the documentation is a little misleading, or confusing.

                      Yep. The documentation mostly addresses the general case, where the preview codec is set to MPEG2 for rendering fast preview. With a production codec set for rendering preview it is safe using preview files for final render. My testing in After Effects, when AE project is set to 32 bit, working space is linearised, all rendered preview, final renders with and without using rendered preview files are dropped into the same comp and the blending mode of all layers is set to 'Difference', results in pure black solid no matter which pair of files I compare.

                       

                      However, rendering preview with a production codec takes much (or, depending on a spec, maybe not so much) longer - that is the trade off, 'cos you may need to render preview several times while editing, whereas final rendering is typically done just once.

                      Does use Max bit depth, and Max render quality actually do anything in CS6?

                      In my understanding enabling 'Maximum Bit Depth' in Sequence Settings is more or less like setting working space into 32 bit. Ticking 'Maximum Bit Depth' in the Export Settings dialog enables to render at higher bit depth, if chosen codec allows to do that. For mor details see this The Video Road blogpost - Steve Hoeg gives quite detailed explanation on the 'Maximum Bit Depth' at the end of the article.

                       

                      See also this discussion about 'Maximum Render Quality'.

                      • 8. Re: Previews and Renders
                        Steven L. Gotz Level 5

                        As Fuzzy says. It is not so much misleading as it is a bit overprotective. If you are able to deal with the consequences when you are wrong, you are allowed to take advantage of the opportunities when presented to you.

                         

                        But think about all of those people for whom all this would be like hieroglyphics. Undecipherable.