Monitoring flickering practicals when overcranking

Wed May 22, 2019 2:56 am

Flickering practicals when overcranking.... flo's and xmas lights and such. I just shot a bunch of cinematic doc style stuff on my Alexa Mini at 47.95fps (2x real speed) and had some subway tunnel flo tubes flicker on subject's face and also issues with outdoor restaurant xmas lights. I should have played the shots back on site but we were moving fast paced; I will be more careful to play back around any potential flickers in the future. This didn't show up on my SmallHD Cine 7 or the director's 703 when watching in real time. Sometimes the effect can "work" but I want to plan for this and be in control. In post if we speed up to 200% (back to normal speed) the flickering goes away, fixes the issue but we lose the slow-motion.
2 questions: First, how can I set things up so that I see the flicker issue on my monitor while shooting? I remember seeing flickering on a Red monitor when over-cranking on a Red camera, and I liked knowing when flicker would occur and being able to try and dial in a workable frame rate and/or shutter angle, but I'm getting no such warning with my own setup. Second, is there any sort of plugin that can help fix the issue in post but still allow us to stay in slow-motion? Thanks.
Stout Film
 
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Joined: Sat Dec 12, 2015 9:08 pm

Re: Monitoring flickering practicals when overcranking

Mon Jun 24, 2019 12:04 pm

Dear Noah,

I think the pull down for SDI-OUT is to blame.
Generally I like looking at a waveform for flickering, which makes also suddle changes more obvious. On ALEXA Mini you can enable an internal waveform. That should be enough of a waveform to see if it flickers.

BMD's Resolve 15 features a de-flicker: https://www.youtube.com/watch?v=28FIrQ-55Ls.

Cheers,
Jan
Jan Heugel
Application Engineer
Jan Heugel
 
Posts: 350
Joined: Wed Aug 13, 2014 3:15 pm
Location: Munich, Germany

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