12 Replies Latest reply on May 28, 2010 1:30 PM by OsakaWebbie

    Time-lapse flicker unchanged after Color Stabilizer

    OsakaWebbie Level 1

      I shot a sequence of still photos of a cluster of roses blooming in front of a blue screen for creating a time-lapse clip, my first time to try that.  I have an NTSC-sized comp that fills the frame nicely with just one of the roses.  As expected, there is flicker due to imprecision in the camera's aperture, and the rumor is that AE's Color Stabilizer effect should fix that.  I have Keylight to key out the blue, and also TimeWarp to speed it up because the rose took longer than I thought to open (although that's optional, as I can just make the clip at its original length and speed it up in PPro when I combine it with backgrounds), but I made sure to put the Color Stabilizer below those other effects in the timeline - that should mean it is applied first, right?  The Color Stabilizer in is "Brightness" mode, and because the rose's petals move, I put the "Black Point" on the blue screen.  But it still flickers - it doesn't look like there is any improvement over not using the effect at all.  Am I doing something wrong?  Naturally, if the Color Stabilizer was being applied after Keylight, it wouldn't work because the background would already be erased, but I think it should be applying it first.  If I have to put the Black Point on some part of the rose, I will have to chase it with a bunch of keyframes, and it may still not work right.  Recommendations?

       

      I wish there was an effect that would simply look at the whole frame's brightness and smooth each frame to a running average of several frames in a row, but as far as I know, such an effect doesn't exist.

       

      Additional info: AE CS4 on Windows XP. The photos were for 1 second each @ f-8 with a Canon Powershot S3-IS, if that matters.

        • 1. Re: Time-lapse flicker unchanged after Color Stabilizer
          Mylenium Most Valuable Participant

          www.gbtimelapse.com

           

          Mylenium

          1 person found this helpful
          • 2. Re: Time-lapse flicker unchanged after Color Stabilizer
            OsakaWebbie Level 1

            I shouldn't need to buy anything else - according to several comments on the Internet, Color Stabilizer should do the trick, or at least improve it, but I don't see any perceptible difference, which is why I think I'm just not using it right.  Yes, I know you'll say that I can just do this one rose with the free trial, but this is only the first of hopefully many time-lapse clips I make.

             

            EDIT: Okay, I was looking at GBDeflicker and thinking some more... Do you know how it works?  I.e. Does it do the rolling average I was imagining would be an effective (albeit painfully slow) technique, or some other method more like Color Stabilizer or something else?  What settings does it have?  If I decide to try it out, I would wait until after an upcoming video trip so that I can try it on a wider variety of time-lapses that I plan to do.

            • 3. Re: Time-lapse flicker unchanged after Color Stabilizer
              OsakaWebbie Level 1

              I just found a "details" page I missed before, so I answered my own question about how GBDeflicker works - it definitely looks like a good tool for challenging time-lapse situations.  But I'm still wondering why, for this kind of video that has totally constant lighting and a background that doesn't move, I can't get Color Stabilizer to work.  If there is anyone with experience using this effect for time-lapse flicker, I look forward to hearing from you.

              • 4. Re: Time-lapse flicker unchanged after Color Stabilizer
                bogiesan-gyyClL Level 3

                > But I'm still wondering why, for this kind of video that has totally constant lighting and a background that doesn't move, I can't get Color Stabilizer to work.  <

                 

                If the lighting and background are constant, there's nothing for Color Stabilizer to do, you should not have needed it at all.

                 

                I'd have processed the individual stills in a batch in Photoshop first, leveling all variables. Bring the stills into AE and output as a movie, reimport. Process the movie with Color Stabilizer, if necessary—and it should not be—and then apply keying, rendering out to ProRes 4444 or Animation.

                 

                There are many flicker elimination tools available that are designed to process timelapse sequences of stills and video. You might want to hit this site:

                 

                timescapes.org

                 

                You need to register to participate but the information is deep and rich. Many After Effects users.

                 

                bogiesan

                1 person found this helpful
                • 5. Re: Time-lapse flicker unchanged after Color Stabilizer
                  OsakaWebbie Level 1
                  If the lighting and background are constant, there's nothing for Color Stabilizer to do, you should not have needed it at all.

                  That would be true if I was shooting with my video camera (which I have done for many a sunrise or other less-than-one-hour time-lapses.  But the problem is that most still cameras do not keep their aperture set while waiting between shots, and even in manual shooting mode with a specific f-stop, there will be slight variations.  The flicker isn't caused by my subject matter, but by my camera.

                   

                  In my case, I'm actually pretty pleased that my camera did as well as it did, considering that it's not an SLR.  The flicker is not nearly as bad as some examples I have seen on the web.  For your benefit, I made two half-resolution Quicktime file of the same 4 seconds of the middle of the sequence - this one has no effects at all, and this one has not just one but two effects added that are rumored to be helpful in reducing flicker: Color Stabilizer in "brightness" mode with the "black point" on the background, and Auto Levels with a Temporal Smoothing setting of 1 second.  (Even at half-resolution and only four seconds, the files are still over 14MB each, because they contain the full frame rate of 29.97 fps, so be patient with the download.)  To my naked eye, I can't see much difference.

                  I'd have processed the individual stills in a batch in Photoshop first, leveling all variables.

                  How does one do that?  I do have Photoshop (CS2),  but I'm not much of a Photoshop expert and have no idea how to get it  to compare levels between even two files, much less do such comparison  in an batch fashion between thousands of files.

                   

                  Thanks for the link.  I didn't see anything directly relevent at first glance (deflicker discussions center around using VirtualDub on a progressive video file, but my source is 3000 still photos, my destination is interlaced DV-encoded video, and I don't really want to process and resave it multiple times if I can avoid it).  But when I have more time, I'm sure I could learn lots about time-lapse in general by reading the forum threads.

                  • 6. Re: Time-lapse flicker unchanged after Color Stabilizer
                    Mylenium Most Valuable Participant

                    I think David is thinking along the lines of the automated whitepoint processing and correction tools in newer versions of Adobe Camera Raw or Lightroom. This wouldn't necessarily be applicable to your CS2 version, but you may still wish to try PS' auto levels and similar tools in a batch action. Maybe it helps some...

                     

                    Mylenium

                    • 7. Re: Time-lapse flicker unchanged after Color Stabilizer
                      OsakaWebbie Level 1
                      ...you may still wish to try PS' auto levels and similar tools in a batch action.

                      Well, I was new to actions as well as all the rest of the terms you threw out there, and my PS is the Japanese version (and prior to CS3 you couldn't select an English UI), so it took a little study, but this page was a huge help - someone else asked how to do that very thing, and the reply was thorough enough to include where in the menu structure to find each thing, which I need when slogging through the Japanese menus.  I did have to click OK on the JPEG Options dialog 120 times for my small 4-second test (argh!), but with more study I could probably figure out how to get it to stop asking.

                       

                      The result is here (no effects in AE - just rendering).  It's still not as smooth as I would like, but it did noticably better than either of the AE effects I tried.  I know it won't work with all kinds of images, because it could change the level dramatically in an undesirable way (e.g. I'm sure that using it on a night sky time-lapse would be a disaster).  But since this image was almost all mid-tone levels to start with, the overall change was fairly subtle and perhaps even a slight improvement.  I would prefer not to have the loss of a JPG generation, but "dem's da breaks".

                       

                      I'll give you both a "Helpful Answer" award - bogiesan (a.k.a. David) for the idea, and Mylenium for both the explanation of David's thought and for pointing out GBDeflicker, which I will probably investigate when I get back from my travels.  I still don't understand why people talk about using Color Stabilizer or Auto Levels in AE for deflickering, when neither seem to do anything on my sequence that should be fairly trivial, but I guess that will remain a mystery...

                      • 8. Re: Time-lapse flicker unchanged after Color Stabilizer
                        bogiesan-gyyClL Level 3

                        > But the problem is that most still cameras do not keep their aperture set while waiting between shots, and even in manual shooting mode with a specific f-stop, there will be slight variations.  The flicker isn't caused by my subject matter, but by my camera.,

                         

                        Of course, my mistake. (I knew that) 

                         

                         

                        > I didn't see anything directly relevent at first glance (deflicker discussions center around using VirtualDub on a progressive video file, but my source is 3000 still photos, my destination is interlaced DV-encoded video, and I don't really want to process and resave it multiple times if I can avoid it).  But when I have more time, I'm sure I could learn lots about time-lapse in general by reading the forum threads.<

                         

                        The bulk of those guys shoot DSLR sequences so there must be something worthwhile there.

                         

                        bogiesan

                        • 9. Re: Time-lapse flicker unchanged after Color Stabilizer
                          OsakaWebbie Level 1

                          I didn't mean that it isn't worthwhile - when I have some free time I plan on perusing that forum and learning lots.  I just meant that I didn't find anything directly related to the question of whether I should be able to do simple deflickering with AE's standard effects, as rumors on other web pages would lend me to believe.

                           

                          Also, DSLR owners can prevent aperture flicker in the first place, by either using a manual lens or semi-disconnecting their lens so that the camera' auto controls don't mess with it (hear the envy in my voice?), so it may be that fewer of the folks on that forum are dealing with this kind of flicker (more like the clouds-rolling-by type).  Mine's an upper-end point-and-shoot, but it's still a point-and-shoot.  My video cameras are more serious models, and I've done lots of time-lapse by simply speeding up an hour of video to a few seconds, but I can't convince a rose to open up in an hour!   And during my trip to wilderness areas away from city nights, I may also attempt a night sky time-lapse - that's something else a video camera can't do, because the shutter speed has to exceed the video frame rate.

                          • 11. Re: Time-lapse flicker unchanged after Color Stabilizer
                            {KMS} Level 2

                            Here is a link to an article with two free filters you can download for Virtual Dub... I have used them and they work well.  I know it is not as handy as having a filter in AE, but it processes image sequences fast.  Hope it helps.

                             

                            http://www.delaat.net/~arne/tltips.html#adv

                            • 12. Re: Time-lapse flicker unchanged after Color Stabilizer
                              OsakaWebbie Level 1

                              Thanks for the links, both of you.  I'm traveling now, and my netbook's display is 800x480, so I'll wait till later to do serious perusing and/or installing software, but one thing I noticed that I didn't realize before is that Virtual Dub can start with my photos - I thought I would have to bring the photos into After Effects and make the video file before Virtual Dub could work with it (and then I'd have to bring it back into After Effects for more processing), but it looks like VirtualDub can video-ize my sequence and do deflicker with the help of plugins.  I'll check it out.