8 Replies Latest reply on May 6, 2009 7:17 AM by Todd_Kopriva

    Best Practice - Output to 240Hrz Monitor

    RMLBIII Level 1

      I have a Canon HF S100 that can record in 24p, 30p, or 1080i. My destination output will be to my new monitor that I have ordered (Sony KDL-46XBR9) that has  Motionflow 240Hz technology and allows 1080/24p input video format.

       

      With the Motionflow technology and the 240Hz refresh rate will my video view better on the monitor if I record in 1080i rather than 1080/24P or 1080/30P?  By recording in 1080i I have two different fields that the motionflow technology can analyze. By recording in 24p or 30p, each frame would have to be reproduced into fields( i.e., 3:2 pulldown for 24p and replicating the frame in 30p mode to create interlace) and thus information to go on.  Since the monitor supports 24p I could simply use AE to remove the  3:2 pulldown and have the monitor produce the video in 24p. The motion technology would convert this to 240fields per second to give a sharper motion.

       

      But it would seem that having a field 1 and field 2 (field two reflecting video at 1/60 of a second later than field 1) would provide the motion technology with more information to predict the motion and thus better quality than if it had to make its prediction based on only 24 or 30 frames per second. 

       

      Any comments would be greatly appreciated.

       

      Robbie

        • 1. Re: Best Practice - Output to 240Hrz Monitor
          Mylenium Most Valuable Participant

          RMLBIII wrote:

           

          My destination output will be to my new monitor that I have ordered (Sony KDL-46XBR9)

           

          Can I give you my residential address and have you send me one, too? I think your considerations make sense, though I would argue, that in 24p mode it probably suppresses a few of its functions, anyway, to give you that cinematic feeling. Otherwise it would kill all that grain and noise that makes film look like film. I also think one should not mistake the alleged 240 Hz as the overall refresh rate. These monitors merely use special switching patterns on their cells to trick the human eye into seing things sharper... Anyway, I guess before this becomes a "the blind leading the blind" matter, you will only learn the full truth through your own experimentation. Have phun with your new gadget!

           

          Mylenium

          • 2. Re: Best Practice - Output to 240Hrz Monitor
            RMLBIII Level 1

            Hi Mylenium,

             

            The motion technology actually evaluates the motion change between each successive two frames and then makes predictions on what has occurred over the period of time between the two frames. The technology then creates 8 additional fields between each 24p frame (thus 240 fields per second) giving the video a smoother look.

             

            If I wanted the film look in 24p, I suppose I could turn of the Motion Technology on the monitor but will have to research this further to see if that is an option they offer. Very good point. However, I do know you can't change the 240Hz as the overall refresh rate on the monitor.

             

            Robbie

            • 3. Re: Best Practice - Output to 240Hrz Monitor
              RMLBIII Level 1

              I have done some further research on the monitor. The Sony Bravia Engine 3 technology is embedded in this new KDL-46XBR9 which will ensure improved image quality. 24p True Cinema support ensures movies can be experienced in its original 24frame per second format. With 1080p native Resolution, image quality is expected to be at its best. In addition to this, Sony XBR9 range has an improved and fast Motionflow 240Hz refresh rate technology, where the frame rate has been quadrupled. This higher refresh rate is expected to deliver crispier and sharper images especially in fast motion scenes.

               

              Robbie

              • 4. Re: Best Practice - Output to 240Hrz Monitor
                Andrew Yoole MVP & Adobe Community Professional

                It all comes down to how you want your material to look, and its entirely personal preference.

                 

                If you want your renders to look like a feature film you see at the cinema, render at 24p and turn off the monitor's Motionflow function.  You watch film at the cinema at 24fps, and that's probably how you should watch it on your TV if you want a cinema experience.

                 

                If you would prefer to view the cleanest motion possible, render at 30i and turn Motionflow on.  30i will give you 60 motion timesamples per second, feeding the Motionflow processor with as much temporal information as possible.  Motionflow 240Hz will only need to interpolate 3 out of 4 timesamples for 30i footage.

                 

                 

                A friend of mine has a Sony something-or-other that interpolates to 100Hz, and he keeps the function on all the time.  Personally, I hate the look of it.  It makes feature films look like they were shot on video, to me.  Perhaps its just ingrained and I'll eventually get over my "high frame rate bigotry", but for now at least, film doesn't look like film to me unless it's 24 fps or thereabouts.

                 

                I'm not dissing the technology overall - interlaced television looks great with more fields.  I just prefer movies to look like movies.

                • 5. Re: Best Practice - Output to 240Hrz Monitor
                  Rick Gerard Adobe Community Professional & MVP

                  I always find these discussions interesting. I used to shoot a lot of commercials on my Arri 35 BL and I always shot at 29.97 FPS and transfered full frames to video because the agencies that I worked for didn't like to edit video tapes with 3:2 pulldown and most art directors I worked with hated the look of 3:2 pulldown on video.

                   

                  Now days, most if my NTSC SD video is rendered without fields. What this means is that the fields are still there because NTSC video is always broadcast with fields. When you render without fields or progressive you just send identical pairs of fields to the display.

                   

                  If I'm shooting HD and I want to do any time manipulation I always shoot interlaced because it gives me more than twice as many frames (separated fields).

                   

                  There have been endless discussions about achieving a film look with video. It's getting easier to simulate film gamma and grain, but just converting or shooting 24P doesn't match the temporal look of projected film or the motion blur you get with a film camera. The motion blur when shooting on film comes from the exposure time of 1/51 second (170º shutter @ 24fps), while the temporal effect or movement between frames comes from the frame rate. You can duplicate the temporal effect, but unless your video camera can match the exposure time you can't duplicate the motion blur. You can duplicate the motion blur of CGI (like text) elements in AE by adjusting the shutter angle in the composition settings. If your output device is feeding a standard monitor or is being broadcast the video sent to the screen will be delivered every other horizontal line at a time. Only displays and delivery systems (progressive DVD or Blur Ray players) capable of delivering each row of pixels sequentially can mimic projected film.

                   

                  Now that I've bored you to death, if your delivery system is capable of delivering full frames and your display device has a refresh rate that matches or is higher than the frame rate of the video then you will not be able to detect any partial frames or temporal artifacts in the playback. Retinal retention will smooth out any temporal artifacts in the playback system unless the motion of elements in the frame is in sync with the difference between frame rate and refresh rate. I probably haven't answered your question, but I can promise you that if your animations look fine on a CRT, they'll look fine on a 240 hz monitor. It's nothing to obsess about.

                  • 6. Re: Best Practice - Output to 240Hrz Monitor
                    Mylenium Most Valuable Participant

                    Rick Gerard wrote:

                     

                    Now that I've bored you to death,...

                     

                    You're not boring anyone. You and Dan Ebberts are the two grand seigneurs of the AE world and your balanced and well-versed insights are deeply appreciated even by someone as hotheaded as me. You're an endless source of valuable experience and good advise.

                     

                    Mylenium

                    • 7. Re: Best Practice - Output to 240Hrz Monitor
                      RMLBIII Level 1

                      Hi Rick, Andrew & Mylenium,

                       

                      Thank you very much for your insight. I am new to videography. I just bought my Canon HF S100 a couple of weeks and purchased my first adobe editing software at the same time.  I love this stuff and am reading material and watching tutorial videos as often as I can to get caught up to speed.  As a matter of fact I just stepped up to Adobe Creative Suite 4 Production Premium software, which arrived in the mail yesterday and am excited to learn and use it. 

                       

                      As I understand, one function of AE allows you to remove the 3:2 pull down (reverse pulldown), which I would like to be able to do when I shoot in24p.  Although my camcorder can shoot 24p it records it to 60i by applying the 3:2 pulldown.

                       

                      I have a question with the workflow when using reverse pulldown function in AE.  I want to reverse the pulldown, edit my video, add compositions and then output to 24p.   I think the best way to proceed is to import all my video clips from my shoot into AE and then interpret each clip and remove the pulldown. Once that is accomplished I should then do my rough edits in Adobe Premiere CS4 and then using dynamic links export it to AE to complete my affects. I understand that by using the dynamic link the video is no decompressed.  After removing the 3:2 pulldown in AE, do I simply save each clip to my hard drive and then import the 24p clips into Premiere or do I transfer all the clips to Premiere via the dynamic link? I think if I save the clips to the hard drive a render occurs. It is my understanding that you really don’t want to do  a render until your ready to output your final product because each time you render you could be losing quality.

                       

                      Lastly, Rick where can I read up more on motion blur and shutter speed?

                       

                      Thanks,

                       

                      Robbie

                      • 8. Re: Best Practice - Output to 240Hrz Monitor
                        Todd_Kopriva Level 8
                        > Lastly, Rick where can I read up more on motion blur and shutter speed?

                         

                        You can start with the "Motion blur" section of After Effects Help. That document and its comments contain some links to articles by Mark Christiansen and Chris & Trish Meyer.