8 Replies Latest reply on Jul 9, 2011 3:59 AM by Dave Merchant

    Need Help to remove flicker from DSLR Video

    Tcosmos357

      Im working in Adobe Premiere Pro CS5 with a DSLR timeline.

      Im using a EOS 7D, Nikon D7000, and a T2i.

      The video was taped at an executive office and I had his two desk monitors as a background.

      The canon footage has a problem, the monitors have a banding/flicker effect on them and it is quite distracting

      I have tried using the standard anti-flicker effect (under motion effects) to no avail.

      Does anyone know how I can remove this banding, it is very crucial to the overall video and I would be willing to use a third party

      plug-in.

       

      Thanks in advance for any help you can provide.

        • 1. Re: Need Help to remove flicker from DSLR Video
          the_wine_snob Level 9

          Welcome to the forum.

           

          Is the flicker just in the monitors behind the subject, or overall?

           

          If only in the monitors, is the display on them important to the shots?

           

          If not, it might be easier to just "drop-in" an image of the desired screen, and use Track Matte Keying, and possibly some Corner Pin, or similar Effects, to make it look right.

           

          Good luck, and please let us know a bit more,

           

          Hunt

          • 2. Re: Need Help to remove flicker from DSLR Video
            Jim_Simon Level 8

            That kind of flickering needs to be compensated for by adjusting the camera's shutter before you actually shoot footage.  It's typically called synchro scan, clear scan or variable scan.

             

            I don't think you can fix it after the fact.

            • 3. Re: Need Help to remove flicker from DSLR Video
              Todd_Kopriva Level 8

              > I have tried using the standard anti-flicker effect (under motion effects) to no avail.

               

               

              That is not for frame-to-frame fluctuations. It's for flickering that comes from thin horizontal detail flashing on and off because of interlacing.

              • 4. Re: Need Help to remove flicker from DSLR Video
                Tcosmos357 Level 1

                Thank you for your quick responce Bill,

                The monitors are not mission crucial and the cameras are on tripods so keying wouldn't pose to much of a hassle,

                However because the executive is the head of a software company it is important that ever effort be made to preserve the visibility of the screens.

                As for compensating with shutter speed: I'm not sure what the optimal speed would be I tried a range from 30-100/ of a second and they still had some visible banding, 30 seemed to do the best job on the D7000 (the camera I operated) the camera operator for the Canon cameras did not properly adjust his cameras.

                So is their anyway to reduce or remove the monitor banding in post?

                • 5. Re: Need Help to remove flicker from DSLR Video
                  Colin Brougham Level 6

                  If you can find a frame of the shot that doesn't show any flicker or banding (and assuming that the screen is still, not changing), you could export a still image of that frame, bring it back into the project, place it above the original shot in the sequence, and then use a matte effect to hide everything but the screen (4-point or 8-point garbage matte would work). This is again assuming that it's just a static screen, and that the shot is locked down, and that nothing obscures the screen in the original shot, e.g. a moving arm. If you have that scenario to deal with, this would be a job for After Effects.

                  • 6. Re: Need Help to remove flicker from DSLR Video
                    the_wine_snob Level 9

                    Going back a bit, we were charged with doing displays in monitors in similar situations for HP, IBM, and many others. We always dropped in the best images possible, to make the displays look like an ultimate display.

                     

                    That was where I was heading with the Track Matte Keying, and possibly the Corner Pin Effect, if the monitors are not "face-on."

                     

                    Even if one has to create the display in PS, or even AI, that would be better than a flickering display.

                     

                    If you have access to the software, and can produce the display, that would be better than trying to find a frame that looks just OK. I always try to attain the very best, rather than scrape by with "good enough."

                     

                    I was just not sure which "flickering" you were alluding to.

                     

                    Hope that helps, and good luck,

                     

                    Hunt

                    1 person found this helpful
                    • 7. Re: Need Help to remove flicker from DSLR Video
                      Jim_Simon Level 8

                      is their anyway to reduce or remove the monitor banding in post?

                       

                      Not that I'm aware of.  You can only cover it with something else, as per Bill and Colin's suggestion.

                      • 8. Re: Need Help to remove flicker from DSLR Video
                        Dave Merchant MVP & Adobe Community Professional

                        In terms of dealing with it at capture:

                         

                        True "video roll" is not a problem on LCDs, as there's no scanning beam - the display flickers all at the same time. Unfortunately with the rolling shutter in a DSLR, the sensor read order clashes with the flickering of the display leading to banding if the shutter speed doesn't match a multiple of the refresh rate. There's no cure-all solution with a prosumer camera - on something like an EX1 you can dial in whatever crazy shutter speed you want until it cures the problem - if you're filming laser displays and find you need 1/62.86, only pro gear can do it - but with DSLRs you have to pick a shutter speed from what's available, and set the monitor to refresh at a multiple of that rate. We've got it easier in the UK with PAL, as we don't have to compensate for the "crystal" values of NTSC.

                         

                        DSLRs do however have one advantage - the live view on the back of the camera shows the effect too, so you can tweak settings in real time and find the best combination.

                         

                        CRTs displaying broadcast TV are easy to deal with, as you can usually match your shutter speed with the stock options on a DSLR (1/60 for NTSC, 1/25 for PAL). CRT monitors for computer display can have a whole range of strange scan speeds depending on the model and resolution (60, 70, 80, 90 Hz), and if you can't find a match with your available shutter speeds, again change the sync refresh rate in the computer's display settings. You may still get a thin black line on the display, but from a distance it'll look OK.

                         

                        If for some reason you need to shoot 24fps and have an NTSC monitor in the shot, the trick is to keep a matched shutter speed (1/60) so you're running a non-standard 144-degree shutter angle. In the film days, Arri made special 144-degree shutters for this type of work, and you could also rent TVs converted to scan at 24fps, but it played havoc with lighting. Now you can get 144 deg with the standard settings on most DSLRs, or as said previously turn the thing off when shooting, and paint it back in post (which has the second advantage that you can mirror the footage for composition purposes without mirroring the stuff on the screen). Just remember to blur the composited screenshot or it'll look fake.