Reducing Video Flicker When Using LED Panel Lighting

Another of my occasional 'no machining' videos: This time I address the flicker I was sometimes seeing on my recordings, particularly on those shots which are subsequently sped up. Flicker may not be the right word, but I'm not sure in this context that 'hum-bar' is either, so I'll stick with 'flicker'. Anyhow, this is something that I first came across back in 2018 ( • Workshop LED Panel Lig... ) so this is a bit of a re-visit to that topic.
During the course of making this film I have come to better understand why the 'flicker' looks the way it does (in particular why I see narrow bands across the frame, not a whole field brightness change), which is related to the rolling shutter on my CMOS camera. It would have been interesting to compare the effect against a global shutter (CCD) camera, but I don't have one to hand. Some high end CMOS cameras now implement global a shutter arrangement to help minimise rolling shutter artefacts, but it will be a while before this technology filters down to my price bracket. Hopefully I've proven that a handful of electrolytic capacitors can mitigate the problem for my modest needs.
This isn't the film I'd planned to be publishing in summer 2022, but one or two niggles in the workshop made it feel that it would be worth the effort to pause the project I was on with to try to sort them out...
The first niggle was reducing the to-and-fro rock on the lathe, and was covered in a recent pair of shorts ( • Threading With a Homem... and • Milling a Radius Witho... )
The second was the flicker issue. Hopefully with it now resolved, I can get back to finishing what I was part way through making. Unless something else crops up 😉
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If anyone would like a bit more information on the instantaneous frequency wobbles present on the mains, this makes interesting reading: mainsfrequency.uk/
For a little bit of further reading on rolling versus global camera shutters, and the artefacts they can generate take a look here: tinyurl.com/3p47ks83 and tinyurl.com/wbd6y8yy
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Manually subtitled for accuracy: click the CC box
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Shot: HDC-HS700 1920x1080 50P AVCHD
Edit: DaVinci Resolve 17.4.4 ProRes 422
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[@dirtboy896]

Is this a machining channel or electrical engineering and cinematography deep dive channel

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Just trying to improve the former by doing a bit of the latter 👍 🇬🇧

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All of the above and I love it 😆

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@@TheRecreationalMachinist - At this age I can only now dream to be this clever and well rounded. Thank you for providing such inspiring content with practical examples of how an electronics background beautifully compliments mechanical capabilities. 👍😎👍

[@jamiedhuskey6643]

You smart man , I are not that smart😢

[@tmth.stevens]

How does this channel not have a million subscribers!?! This is amazingly well made

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Instantly pressed the subscribe button after watching this. Superb quality throughout.

[@TheRecreationalMachinist]

Thankyou for your kind words 👍 🇬🇧

[@noimagination99]

Me too, 2nd video I have seen from this channel. Most excellent! Top quality video!

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Just found this channel through shorts. Make sure you ask people to follow the main channel etc. Huge potential to be had here!!!

[@noimagination99]

The demo with beads on wires was excellent!

[@knowitallproductions1178]

Not even thru 1st run of this instant YT classic, and it’s an extremely tight race, but 3:50 w/ CC on, his voice almost imperceptibly changes, but he transcribed it as an exclamation; “…factor of 10!” I love it b/c it is British understatement encapsulated. As is the perfect narrator voice soothingly describing his apparent PHD level mastery of 3-4 EXTREMELY technical & nuanced disciplines, as well as an effortless penchant for creativity in storytelling, A/V editing as a augmented enhancement of the visuals, concepts, and forces at play that allow even an utter layman to understand far more than could ever be expected. An absolute masterpiece. (& this guy is a WIZARD machinist, just whoa)

[@ACYONE98]

Great work on the sound effects ! Really adds a nice touch

Good visualization of the effort you have to put into the filters.

[@joshuaharlow4241]

Comment because you deserve more subscribers. 10 out of 10, would watch again.

[@craigtate5930]

Love the brass thumb screews in your next video!

[@Rustinox]

That's really interesting. I have to check on that. Thanks for posting.

[@Wasaia]

Thumbs up for the excellent production- and soundquality of this video! Very professional. 👌

[@robertstewart1464]

Leaving well alone sometimes isn't a bad optionals. Mains electricity is no joke, I've wired myself in by accident a few times and rode the lightning!

[@spenmac]

Nice effective yet simple fix.

[@ifell3]

Was going to say you need to set the camera to the frequency of the lines, if 50hz go 25, 50 or 100fps or use a capacitor! Saves me doing a video about it!

[@jacobiceps9452]

Excellent video!!

[@TheKnacklersWorkshop]

Hello Matt, Interesting video... at sometime in the next couple of years I will be moving the workshop and I plan to have all LED lights so this could be very useful to me... Thank you. Take care. Paul,,

[@MidEngineering]

I just recently saw this banding effect on some of my videos & it's interesting to see someone else getting it. I've been replacing my fluorescent tubes with LED tubes with no issues until I got a new camera. The old one recorded AVI files at 29.97 fps, but the new one records MP4 at 25 fps (or 50 or 100fps which produce closer bands). Hoping it's just being caused by random variations in mains frequency...

[@frvo]

Love your videos. 👏🏼

[@GuildOfCalamity]

I wouldn't worry about the short, you've essentially created a passive high-pass filter using the cap; you could also use a coil in parallel to get the same effect.

[@TheAyrCaveShop]

Very helpful ! hitting subscribe !

[@richardbradley961]

RREALY ENJOYD THAT, THANK YOU. REGARDS R.

[@5Breaker]

I wonder by how much the powerfactor is affected with the additional cap.

[@edpopelas2844]

👍

[@Wasaia]

Question: I have some LED work lights, which I use with amber coloured gel filters for small video- and theaterprojects. (No budget for professional led pars) I am sensitive to the mains flickering/refresh rate of these lights and tend to get nauseous after a while. Could I remove this flickering by adding some capacitors? Do you know of an of the shelf product I could hook up to solve this or is DIY the only way?

[@Tome4kkkk]

Why the hell it even needs to be done?! This should be integrated into the LED power supplies.