My Enemy Flicker

on February 10, 2022

As a kid there was a standing joke in school when it came time for English assignments. Every year some other student would attempt to sneak in a holiday book report on " My Friend Flicka ", and every year they would get a failing mark in English. Mary O'Hara was not a bad writer, nor was the book awful in itself, but English teachers used to use it as a yardstick of committent and then beat the students with that yardstick.

Well, Flicka may have been friendly, but flicker is not. The person who makes videos will encounter it in many guises, and they are all bad news. People are sensitive to two things when watching moving pictures; audio quality and flickering light. You can generally get an adequate level of the former by choosing a camera system with a separate mic input and then attaching a good quality microphone like a Røde onto it ( Shameless CE shop plug... ). Getting rid of the flicker is another matter.

Note that still shooters may still be plagued by it, or a form of it. I tried to cover a stage performance at a school theatre that had a large projection screen behind the stage. Scenes were thrown onto it from a projector booth behind the seats, but they were done with stills and videos that had a fixed frame rate. If I chose the wrong shutter speed I was faced with a wide dark band somewhere in the backdrop behind the performers.

Luckily I saw the problem in time at the rehearsals and could experiment with the shutter speed. As this and the lens aperture were running on the barely-acceptable limits to stop action, it was up to the high ISO capability of the Fujifilm X-T2 and later the de-noising section of Lightroom to get acceptable quality. I became leery of stage screens.

This was re-enforced when asked to do a video on a different stage with similar projection backdrop. Here there were moving scenes projected and I found that my camera was picking up rolling banding and flicker from the third row. Fortunately I could run short test sequences and find a frame rate and shutter speed that could eliminate it, but it was nervous shooting nevertheless.

I suspect there may be programs in editing suites that can deal with this sort of thing - mine is basic and I try to present it with the best footage I can before asking it to modify anything.

Note that you can be flickered when you least expect it. My Bunnings lights that illuminate my product table are darling items but nowhere near as good as dedicated video lights. They come in various sizes and powers and the two main wash ones are free of any flicker on still work. But if I add one more - slightly larger - as a spot or key, it flickers like mad in the LED screen. Fortunately the final shot is evenly lit.

I realise this is all perfectly normal for the electrical engineers amongst us but the fumbling experimenters are frustrated. We'd like to give the problem the flick...

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