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  • Cross hatch, screen door

    So what's the deal with this. Do all Ursa 4.6 cameras have this issue or is it only on some cameras? Is the official fix to set pan and tilt in resolve to .5? Who here has an Ursa 4.6 without cross hatching?

  • #2
    Originally posted by TheInternet View Post
    So what's the deal with this. Do all Ursa 4.6 cameras have this issue or is it only on some cameras? Is the official fix to set pan and tilt in resolve to .5? Who here has an Ursa 4.6 without cross hatching?
    This is not a problem with the camera, its a simple aliasing issue as the pixels on the ursa mini footage are so sharp your monitor will not be able to display them properly.
    If you export the file after editing you will not see this issue with certain playback software.
    You would see this on a 1080 monitor and even a 4k monitor but at 1:1 on a 4.6k monitor or above it would not show up.

    http://web.stanford.edu/class/ee368b.../aliasing.html

    Here's some info ^^

    Comment


    • #3
      Originally posted by Jake Lutz View Post
      This is not a problem with the camera, its a simple aliasing issue as the pixels on the ursa mini footage are so sharp your monitor will not be able to display them properly.
      If you export the file after editing you will not see this issue with certain playback software.
      You would see this on a 1080 monitor and even a 4k monitor but at 1:1 on a 4.6k monitor or above it would not show up.

      http://web.stanford.edu/class/ee368b.../aliasing.html

      Here's some info ^^
      Interesting, so if you're correct, then all 4.6 cameras have this issue. Maybe the world isn't quite ready for 4.6k.

      Comment


      • #4
        Originally posted by TheInternet View Post
        Interesting, so if you're correct, then all 4.6 cameras have this issue. Maybe the world isn't quite ready for 4.6k.
        Careful - it means all 4.6k cameras on the face of the Earth - regardless of maker - will cause your MONITOR to react this way.


        But you're right that most of the rest of the video equipment industry is not quite ready for 4.6k.
        Cameras: Blackmagic Cinema Camera, Blackmagic Pocket Camera (x2), Panasonic GH2 (x2), Sony RX100 ii, Canon 6D, Canon T2i,
        Mics: Sennheiser, AKG, Shure, Sanken, Audio-Technica, Audix
        Lights: Every Chinese clone you can imagine

        Comment


        • #5
          I wonder if it's specifically the 4608 x 2592 ratio of pixels that is causing this. Do Red 6k cameras have the same problems displaying correctly non-natively on various monitors?

          Comment


          • #6
            Originally posted by TheInternet View Post
            I wonder if it's specifically the 4608 x 2592 ratio of pixels that is causing this. Do Red 6k cameras have the same problems displaying correctly non-natively on various monitors?
            You get different artifact patterns at different scalings. In fact that's a great way to be sure it's NOT your actual footage.
            Change the playback/monitor scaling and if the pattern changes at all, then you know it's just aliasing.
            Cameras: Blackmagic Cinema Camera, Blackmagic Pocket Camera (x2), Panasonic GH2 (x2), Sony RX100 ii, Canon 6D, Canon T2i,
            Mics: Sennheiser, AKG, Shure, Sanken, Audio-Technica, Audix
            Lights: Every Chinese clone you can imagine

            Comment


            • #7
              I'm suffering with the same problem.

              If I want to green-key in After Effects, then I need to render out clips at 4096 x 2304 and set debayer to "best".
              If I choose native 4.6K resolution, I get patterns/noise/crosshatchs all over.

              So yeah. Full 4.6K is unusable (at the moment).

              I've been at IBC last week, and I talked to Blackmagic guy who didn't have a clue about what's causing the crosshatch.

              Comment


              • #8
                yeah, you don't see any patterns at 100 percent scale.

                Comment


                • #9
                  It's not just 4.6K but also UHD. I've had this problem as well. I really haven't been able to render anything out in a 4K master b/c of it. Support had no idea. They told me to turn off "detail" and it seemed like it worked for a minute but no, back to crosshatch.

                  Comment


                  • #10
                    Originally posted by Jake Lutz View Post
                    This is not a problem with the camera, its a simple aliasing issue as the pixels on the ursa mini footage are so sharp your monitor will not be able to display them properly.
                    If you export the file after editing you will not see this issue with certain playback software.
                    You would see this on a 1080 monitor and even a 4k monitor but at 1:1 on a 4.6k monitor or above it would not show up.

                    http://web.stanford.edu/class/ee368b.../aliasing.html

                    Here's some info ^^
                    Are you really sure it's aliasing caused by a "normal" image? It seems to me it's aliasing caused by images that suffer from the maze effect. I'm not sure all minis have the maze effect to the same degree, mine certainly shows it pretty easily when somewhat underexposed. Needless to say, scaling down an image of a maze pattern will definitely cause crosshatching.

                    Comment


                    • #11
                      Originally posted by AaronChicago View Post
                      It's not just 4.6K but also UHD. I've had this problem as well. I really haven't been able to render anything out in a 4K master b/c of it. Support had no idea. They told me to turn off "detail" and it seemed like it worked for a minute but no, back to crosshatch.
                      Are you recording in UHD, or recording in 4.6k and trying to deliver in UHD?

                      Comment


                      • #12
                        Originally posted by Jake Lutz View Post
                        This is not a problem with the camera, its a simple aliasing issue as the pixels on the ursa mini footage are so sharp your monitor will not be able to display them properly.
                        If you export the file after editing you will not see this issue with certain playback software.
                        You would see this on a 1080 monitor and even a 4k monitor but at 1:1 on a 4.6k monitor or above it would not show up.

                        http://web.stanford.edu/class/ee368b.../aliasing.html

                        Here's some info ^^
                        That is not true at all. You're thinking of a different issue. This is about cross-hatching, not aliasing. If you zoom in on the image you can see a crosshatch pattern. It happens with raw and ProRes footage, and shows in different software, therefore is not a software issue. It's an issue with the way the camera is processing the image off the sensor. https://forum.blackmagicdesign.com/v...=50175#p290122 and https://forum.blackmagicdesign.com/v...hp?f=2&t=51936

                        Comment


                        • #13
                          Originally posted by mikeh View Post
                          That is not true at all. You're thinking of a different issue. This is about cross-hatching, not aliasing. If you zoom in on the image you can see a crosshatch pattern. It happens with raw and ProRes footage, and shows in different software, therefore is not a software issue. It's an issue with the way the camera is processing the image off the sensor. https://forum.blackmagicdesign.com/v...=50175#p290122 and https://forum.blackmagicdesign.com/v...hp?f=2&t=51936
                          The names folks have been giving these issues have grown quite confusing.
                          I don't think anyone here is wrong - just that some may be talking about different issues than others because of confusion with these names and somewhat vague descriptions.

                          Really, the FIRST thing anyone should do who thinks they are having ANY of these problems is to render out a full size 1-to-1 pixel ratio clip and check to see if the problem is really IN the footage or not. This will help narrow things down quite a bit.
                          Cameras: Blackmagic Cinema Camera, Blackmagic Pocket Camera (x2), Panasonic GH2 (x2), Sony RX100 ii, Canon 6D, Canon T2i,
                          Mics: Sennheiser, AKG, Shure, Sanken, Audio-Technica, Audix
                          Lights: Every Chinese clone you can imagine

                          Comment


                          • #14
                            Anyone not seeing crosshatching? I've yet to see someone say they dont.

                            Comment


                            • #15
                              I notice cross hatching in Resolve preview screen when recording UHD and the project setting is set at UHD, it goes away when project setting is set at 1080p.
                              I also notice cross hatching on a HP monitor that does not display 1080p, it gave a black border on 1080p footage. It goes away when viewing in actual pixel size.

                              Comment

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