How to avoid flickering lighting?

[John Sharaf]

I don’t see any flickering
I suspect it’s your monitor
Did you shoot at 24P?
Many monitors flicker at this rate
You’ll need to monitor at 30FPS (to include the repeated 3:2 pulldown) to view properly.
It’s either a setting in the monitor or the editing platform

JMHO

JS

[Gary Huff]

[Sam Baker] “There are points where the lighting fluctuates but this wasn’t noticeable at the time, and it is consistent in the rest of my footage.”

I don’t notice any lighting fluctuating on my monitor.

[Gary Huff]

[john sharaf] “Many monitors flicker at this rate. You’ll need to monitor at 30FPS (to include the repeated 3:2 pulldown) to view properly.”

I shoot the vast majority of my content at 24p and I’ve never needed to set my computer monitor. Pulldown is not required.

[Mark Suszko]

Didn’t see your sample: I don’t make a habit of going to strangers’ Drop Boxes. But.

If this was not a DSLR, I would advise adjusting the variable frame speed, what Sony calls: “Clear Scan”. I need to sometimes do this when the lighting is LED-based. I don’t know that DSLR’s have a similar function.

This might be somewhat repairable in post, using color correction tools to select a narrow range and then adjusting just that band to “blow-out” in a steady color/light level. Not perfect, but sometimes saves the shot. There is also some DSLR software that can treat the issue in-camera with a corresponding variance in shutter, but I don

[Todd Terry]

I’m directing on location today and not where I can download the footage to view, but I’ll throw this out there….

What kind of lamps are in your two instruments?

If they are fluorescent bulbs, that might be the culprit.

Bulbs like halogen and tungsten bulbs are continuous… the hot filament still glows between power cycles and the light is constant. But many other types of light… flos, HMIs, etc…. are not continuous… they actually quickly flicker along with the 60Hz cycle of the power. If this is not in synch with your camera shutter, you will get troubles. It can be anywhere from a rapid flickering to a slow phasing over a several second period.

I’m not saying that’s your issue, but if it is then you need to shoot with a shutter speed that is exactly the same as the AC power source. This requires a camera with a shutter mode usually known as “clear scan,” when you dial in the exact correct shutter speed… so instead of setting it at 1/48th or 1/60th, it’s more like 59.043 or 60.849 or whatever.

I don’t use DSLRs to shoot video, but I’m doubting that’s something your Canon will do. You’ll need a proper (and higher end) video camera to do that. Or the easier/cheaper fix… use continuous lighting… e.g. tungsten, halogen, or LED (note that most but not all LEDs are flicker free these days. Any that operate on batteries will be, but AC powered ones might flicker, especially ones that do not use a transformer to step the juice down to 12V DC).

On another note… I too shoot 24p almost exclusively. I’ve never had a monitor flicker, whether it be a high-end “real” monitor, LCD, LED, CRT, or just the cheap 12V LCD TV that we sometimes use.

T2

__________________________________
Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com

[Sam Baker]

If you scrub through, it brightens and darkens at points.

[Todd Terry]

“If you scrub through, it brightens and darkens at points.”

Is it uniform and regular?… as in, does the brightness hit its peak at uniform intervals, such as every five or eight seconds or so, exactly the same over and over? If you speed up a clip where this occurs it is often more evident… something that looks fine at normal speed will show brightness differences when played back at, oh, 800%, or when scrubbed through.

If that change is precisely uniform, that’s the phasing I was talking about in the post above. In that case you need to change the light source to a continuous source, or shoot with a camera that has a clearscan mode.

T2

__________________________________
Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com

[Sam Baker]

These are the lights: https://www.amazon.co.uk/gp/product/B0089HTJE4/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

I think they’re LED and it says continuous in the listing. The footage was shot at 25p and I need it that way.

[Sam Baker]

In that clip, there is a bit of an ebb and flow, with it getting brighter and then darker about three times (but static for the first 5 seconds).

However, in most of my other footage with the same person, it’s not there at all and the lighting stays consistent, with a few dips towards the end.

It was all shot in the space of 20 minutes so I don’t think it’s phasing.

[Todd Terry]

They’re throwing around the word “continuous” in a different way than we’ve been talking about it here. They just mean they are not strobes that flash. That doesn’t mean they are true continuous lights.

That Amazon listing is very light on exact specs…. but based on the fact that the instruments are dirt cheap and that they are listed at 80 watts and plug directly into AC power, then I guarantee you that they are flos, and that very likely is your problem.

T2

__________________________________
Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com