Archive for June, 2014

PostHeaderIcon A Flicker of Truth

Whether you’re shooting time-lapse, fast or slow motion, or even more routine scenes under temperamental fluorescent lighting, chances are you’ve confronted flicker and have thrown up your French flag in frustration. Today the flicker menace seems even greater owing to most cameras’ tiny viewfinders that make it difficult to spot on location, increased use of LEDs and other discharge lighting, and greater availability of cameras capable of shooting at off frame rates.

Flicker may be seen as a faint background pulsating effect, or more dramatically as a significant fluctuation in exposure from frame to frame. In most cases the flicker may be reduced or eliminated through use of the ClearScan or Synchroscan shutter found in newer video and hybrid cameras like the Panasonic GH4. Fine shutter tweaking should always be your first course of action. Shooting 24p in 50Hz countries? Set the camera shutter (in degrees) to 172.8º. Shooting 30p in 50Hz countries? Set the camera shutter to 108º, 216º, or 324º. The use of a camera’s fine shutter is imperative if one is to avoid flicker stemming from the field frequency mismatch when shooting abroad.

Nevertheless regardless of our best efforts the specter of objectionable flicker will occasionally raise its ugly head, and this is where Digital Anarchy’s Flicker Free plug-in can save your backside. Compatible with Final Cut Pro 7 & X, Avid, Adobe Premiere, and Adobe After Effects, the plug-in can be especially effective for eliminating flicker in time-lapse and slow-motion footage, and in certain scenes illuminated by HMIs, fluorescents, and LEDs.

The Flicker Free software is simple to use with presets for time lapse, slow motion, computer/TV screen, and archival film restoration. This level of simplicity is possible because the flicker cadence in most cases is a regular pattern. In case of need further tweaking of the underlying parameters is still possible from within the plug-in.

Flicker Free’s THRESHHOLD setting specifies how much change in brightness is tolerated from frame to frame. While significant changes in brightness from frame to frame are usually deliberate, this is not the case when shooting neon or in an out of sync 50Hz/60Hz environment.  In such scenes exhibiting a brightness fluctuation in excess of 20 percent from frame to frame Flicker Free is not likely to offer much help.

Fig 2 Flickerfree PRESETS

Digital Anarchy’s Flicker Free plug-in is supported in most major editing platforms. It will work either very well. Or not at all.