By Brady Betzel
The commercials that aired during the Olympics coverage showed off some of the latest and greatest camera work and visual effects I’ve seen on the small screen. Some were just breathtaking. I mean who doesn’t love snowboarders doing 1080s at around 5% speed over a 100-foot gap in the snow at night? I know I do. You may have also noticed strobing or flickering in the lights as a result of the high-speed frame rate under the lights.
Without getting too deep into the physics and optic technicalities of filming, lights and cameras don’t necessarily get along when run at high-frame rates (Usually more pronounced at or above 240fps. If you are interested, Google “Alternating Current and Incandescence” while filming.). Keep this in mind while filming at high-frame rates for slow motion, but if you forget Re:Vision Effects has come to your rescue with its De:Flicker plug-in for After Effects CS5 and up, including Adobe After Effects CC. The full version costs $249.95, and the render-only option is $49.99.
As I watched the Olympic commercials on broadcast TV and YouTube I was a little bummed out that they didn’t spend a little extra money to fix this, maybe it was an aesthetic choice or maybe no one realized that you could remove the strobing effect relatively easily. When talking with the guys at Re:Vision, they explained how their De:Flicker plug-in worked, but more importantly that it was easy to use. I love plug-ins that are detailed and in depth, but I also love plug-ins that know what they are supposed to do, and do it well. This is exactly what the De:Flicker plug-in does.
If you have any sense of slow motion and how it works in After Effects you undoubtedly have heard of Twixtor, the kingpin of slow-motion plug-ins (YouTube Twixtor and you will be amazed at how awesome a balloon popping at 1% speed looks). Re:Vision Effects makes Twixtor. Go to their site (www.revisionfx.com) and you will see that they have an ultra-high standard for the products they release, and De:Flicker lives up to the name.
Recently I’ve been obsessed, to put it mildly, with my GoPro Hero 3+ camera. For this review I thought it would fit in perfectly if I could shoot 240fps. Now while you may be thinking, the GoPro Hero 3+ does shoot 240fps. It does, but it’s at an abysmal WVGA resolution (800×480), so how is that useful? That’s what make it the perfect test, because what camera does everyone use these days to shoot sports? GoPro. So why not test out a plug-in that claims to correct strobing in almost ALL cameras, with one of the lower resolutions with the most noise? I wanted to throw the hardest footage at De:Flicker and see how it processed it. What De:Flicker did was exactly as promised and even better.
PUTTING IT TO THE TEST
For the purposes of the review, I shot a quick clip in low light, with high contrast, indoors. I brought the footage into After Effects, and once slowed down you could immediately see the strobing. You could also see a substantial amount of noise had been produced because I shot in possibly the worst lighting known to the modern world at a low resolution. Once I installed De:Flicker, which was painless by the way, I wanted to see what I could do without reading any features and/or watching any tutorials.
I jumped in and tried to process the footage, unfortunately it wasn’t as easy as I had thought. I messed around with the presets and even saw a setting for Pulsating Highlights, which I thought made sense. I got the footage partially corrected but not where I wanted it. So I then sought out Re:Vision Effects tutorials for De:Flicker which can be found at http://help.revisionfx.com — tutorials for all of their products can be found there. After a quick four-minute tutorial I made the right adjustments and my high-speed footage was surprisingly usable. Now I say usable because I have worked on talk shows as well as reality television and the footage we get isn’t always “usable,” but we have to make it work. De:Flicker is a plug-in I would suggest for anyone dealing with footage that is sent in from their viewers or characters, it can take horrible slow motion with tons of noise and/or strobing and make it watchable.
Now for some specifics, De:Flicker installs a suite of three plug-ins: De:Flicker High Speed, designed for noise and strobing problems inside of high-frame-rate footage; De:Flicker Timelapse, designed for timelapse photography; and De:Flicker Auto Levels, which analyzes and then stabilizes the color and luminance levels of your footage — used in conjunction with the other plugins to produce a great piece of footage.
De:Flicker High Speed, as I have been raving about, works great once you know the settings you need. In fact, if you have multiple areas of flickering you can use multiple copies of the effect to isolate different areas without touching the rest of the footage. The options under the hood range from Time Window, the frames that are compared when calculating how to keep the light constant; Method, the way in which De:Flicker processes the flicker removal… I used the Noise Clean Method 1 when processing my test footage; and Gamma Adjust, if you want to adjust the Gamma inside of De:Flicker.
De:Flicker Time Lapse helps correct for color shifts that can occur as a timelapse progresses, such as clouds darkening a scene. Inside you will see many of the same options as in the High Speed plug-in as well as options for Adjusting the Color Levels in the Global Color Correct Method (which even allows you to select a sample keyframe as a reference for the entire timelapse, and you can even animate between different reference frames); Sampling Block Size; Method (Average Match, best for shots that are static; Cumulate Match, best for shots that have pans; Coarse Color Transfer for shots with a large depth of field); and even Contrast percentage.
De:Flicker Auto Levels helps to correct dramatic shifts in lighting, such as a camera flash. First you click Start Analysis, and De:Flicker Auto Levels analyzes each frame of the footage. You can then view the analysis in a graph; most likely it will show exactly where the color shifts are. If you are lucky enough to find a constant wave you may be able to use the Filter Out Frames drop down and select which frames you want to keep by either using even frames or odd frames. De:Flicker drops out the unwanted frames of the footage and replaces them with new interpolated frames. Auto Levels is also a good option if you want to see, on a graph, where the problem areas are and keyframe the effect only at those points so you don’t waste render time, which can be heavy. So keep that in mind. It’s a powerful tool but that also can come at the price of render time.
You can use De:Flicker in a variety of ways. If you have a straight shot of flicker high-frame-rate footage you may be able to get away with the stock settings in De:Flicker High Speed. If you have a timelapse with color shifts you can set reference keyframes and correct dramatic shifts in lighting conditions. And if you have a shot where you need to correct color shifts as well as pulsating lights you may need to use a combination of De:Flicker Auto Levels and De:Flicker High Speed to isolate tricky areas, remove the even or odd keyframes, and then process in High Speed.
If you deal with footage coming from outside sources, low-light, high speed footage, or sports footage in general, you will want to invest in De:Flicker. You do need to have a decent level of knowledge in After Effects to follow along with Re:Vision Effect’s tutorials, but even if you don’t have a decent level of After Effects knowledge it’s good to stretch your brain and figure this out — because these days as editors are expected to be VFX artists and even footage doctors, so we all need to stretch our brains a little bit.
And check out this link I made showing off some of my results: http://www.youtube.com/watch?v=b1D5y1kTzwQ.
Brady Betzel is an editor at Bunim Murray Productions, a reality television production company. He is one of the editors on Bad Girls Club. His typical tools at work are Avid Symphony, Adobe After Effects CC, and Adobe Photoshop CC. You can email Brady at email@example.com, and follow him on Twitter, @allbetzroff .