12 Replies Latest reply on Dec 21, 2010 7:56 AM by Dave LaRonde

    Flicker in time-lapse

    Karel Bata Level 1

      I've got a prob with flicker in some time-lapse tests due to the fact that the auto-exposure can't be overriden in the camera I'm using.

       

      One fix the pros use is something called GBDeflicker, but it's not cheap, and I wondered if there's a (relatively easy!) fix in AE

       

       

      http://www.youtube.com/watch?v=RJTQOZLCeF0

        • 1. Re: Flicker in time-lapse
          TimeRemapper Level 4

          One of the signature things about time-lapse is the exposure shift. I think it's a nice feature of that aesthetic. However, if you want to get more balance, you can try to adjust various effects (i.e. Levels) under the "Color Correction" sub menu of the Effects menu.

           

          Also, it looks like the trial of the plug-in you indicated is fully functional for 15 days...

          • 2. Re: Flicker in time-lapse
            bogiesan-gyyClL Level 3

            Try this site for some useful suggestions:

             

            http://timescapes.org

             

            May of those guys use AE for the weirdest stuff but they discuss various other products regularly. You seem to be shooting for HDR or you've applied some radical color enhancer. The exposure seems to be stable but the flicker appears to be coming from the fact that cloud shadows are moving in and out of the foreground. Nothing you can do about that except smooth out the frame interval so the shadows slide in and out instead of instantly pop.

             

            bogiesan

            • 3. Re: Flicker in time-lapse
              JesseHarris Level 1

              Bogiesan correctly tells you about the cloud's shadows on the wall.  I think you also wondered why the clouds seemed jerky, and I would ask you what your interval was.  What was the time in between your exposures?  When the clouds are rather low, smoother motion can be achieved by a quick interval, 3 seconds or less - and slightly blurring the motion with a slower shutter speed, like 1/15 for instance, (will require nd filters on the lens).  Or there are methods in AE to smooth out motion - specifically Timewarp, (which I'm still trying to master!!)

              • 4. Re: Flicker in time-lapse
                Mylenium Most Valuable Participant

                As Steven suggested, you could try conventional Levels and other adjustments, but you would have to do it on a frame by frame basis since you need to radjust the histogram/ ranges to be constant around an imaginary mid-point. Also try the various "Auto-" effects. A more complicated process would be to separate the components manually in YUV color space using Channel Combiner and Shift Channels, then smooth out the luminance/ lightness using temporal effects like Echo, CC Timeblend or comemrcial ones like Twixtor, then re-combijne everything and convert back to RGB. You will never get it perfectly smooth, though, even more so if you work based of files that laready have clamped colors in them like JPEGs. Might be able to do a bit more with RAW files but even there there may not be enough headroom in the ranges where you need it...

                 

                Mylenium

                • 5. Re: Flicker in time-lapse
                  Karel Bata Level 1

                  Thanks for the input guys.

                   

                  Please do bear in mind this is just a test to see if this particular camera (a Canon HV20!) and the workflow will yield workable results. And also that the original footage is (intentionally) a bit bland.

                   

                  I went back to the original material, compiled the 0EV tiffs, and found that it's a lot smoother than the final result I'd had.

                   

                   

                  http://www.youtube.com/watch?v=E-dyymOtDXk

                   

                  There's also a lot less flicker.

                   

                  The HV20 camera in bracketed stills mode yields 3 images -1EV, 0EV, and +1EV. I use a GentlEd intervalometer. I don't bother using the 0EV exposure, and tone-map with the other two using Photomatix to generate TIFFS, which are then imported into AE.

                   

                  So I retraced my steps and started a fresh AE project, using the same TIFFSs and the problem seems to have largely gone away!

                   

                   

                  http://www.youtube.com/watch?v=UGOo5NBZhNM

                   

                  The clouds are pretty smooth, and their exposure consistent, though not perfect - but then it wouldn't be with this cheapo set-up. Flicker remains in the shadows, but that's due to the tonemapping. To fix that (a bit) what I could do is mask off the sky, and apply GBDeflicker (looks like I'll have to get it) to the rest. Guess I'll be giving that a go when I have the time.

                   

                  Bit of a mystery what caused the prob in the first place...

                  • 6. Re: Flicker in time-lapse
                    Mylenium Most Valuable Participant

                    Yupp, that looks notably better...

                     

                    Mylenium

                    • 7. Re: Flicker in time-lapse
                      Dave LaRonde Level 6

                      Karel Bata wrote:

                       

                      ...I've got a prob with flicker in some time-lapse tests due to the fact that the auto-exposure can't be overriden in the camera I'm using....

                      Oh, for heaven sake, that's just about the WORST excuse I've ever heard for doing a massive amount of work in AE.

                       

                      Get a camera that lets you override the automatic settings, for cryin' out loud!  Borrow one!  Rent one!  Or, perhaps, do you need to actually open your camera manual, read it and possibly LEARN how to override the auto exposure?

                       

                      It's a very poor craftsman who blames his tools.

                      • 8. Re: Flicker in time-lapse
                        bogiesan-gyyClL Level 3

                        > Bit of a mystery what caused the prob in the first place...<

                         

                        It's not a mystery to me at all. There is a direct cause-effect relationship between your presentation and the interval between frames. Invest in learning how to shoot correctly; post processing timelapse footage is a huge time waster as fas I am concerned. But the topic creates endless discussion and a wide variety of inexpensive and capable products including filters, scripts, and plugins for Photoshop and vide oeditors and After Effects..

                         

                        The problem most timelapse newbies seem to have is assuming they are doing something new. Timelapse is an ancient craft, relatively speaking, and it's easily researched—even in real books! Timeplapse exposure and setup techniques have been perfected within almost every economic and hardware bracket. However, there are minimum requirements for quality and control and they are based on working backwards form your desired results.

                         

                        bobgiesan

                        • 9. Re: Flicker in time-lapse
                          Karel Bata Level 1

                          Two totally smart-*** answers without a hint of a solution between them!

                           

                          Dave, if you knew anything about time-lapse you'd know that exposure fluctuations are very common, hence several software solutions are available, but I hoped someone here might have thought up a way of doing it in AE without my having to buy any such third-party plug-in. My comment was meant as an explanation of the rather large fluctuations in my footage rather than as any excuse.

                           

                          Boglesan (huh?) I've dabbled in time-lapse for over 20 years, starting out on a Bolex. So, what exactly does "a direct cause-effect relationship between your presentation and the interval between frames" actually mean? How does it somehow explain how loading the footage into AE can produce rhythmic fluctuations, but doing it again with the same footage in a fresh project the problem is no longer there? Since you say "It's not a mystery to me at all" perhaps you could offer an explanation rather than some patronising "Invest in learning how to shoot correctly" advice.

                          .

                           

                          Go do your troll-ing elsewhere.

                          • 10. Re: Flicker in time-lapse
                            Todd_Kopriva Level 8

                            Please, do not let this degenerate into a personal attack.

                            • 11. Re: Flicker in time-lapse
                              Karel Bata Level 1

                              I thought it already had...

                              • 12. Re: Flicker in time-lapse
                                Dave LaRonde Level 6

                                Karel Bata wrote:

                                 

                                Dave, if you knew anything about time-lapse you'd know that exposure fluctuations are very common... I've dabbled in time-lapse for over 20 years, starting out on a Bolex.

                                 

                                Hmmm.... that's just about the same amount of time I've been doing time lapses for my TV station.  Instead of a Bolex, I've done it using a Beta SP camera. It's a somewhat more involved task for a couple of reasons, not the least of which is the compressed contrast range of video compared to 16mm film.  But the exposure issues remain the same.

                                 

                                So I stand by what I wrote earlier.  If I can shoot a time-lapse city sunset on video without losing the foreground in black, you can shoot a building with the sun at your back using a DSLR.  You simply have to know what you're doing.