[00:00:00] You’ve undoubtedly seen in travel, videos and in some tech reviews, flickering lights. The flicker might be coming from environmental light in travel videos, or from the LED buttons or LCD displays on technical devices in tech reviews. I’m going to show you how to fix that.
[00:00:29] Now, as far as the ‘why this is happening’, I actually did a big, long, super-nerdy video on this a while ago and I’ll link to that down below and at the end of this one. If you really want to get into the math on it, I encourage you to watch that; it’s quite fascinating. But in this video, we’re not going to get into that — just into how to fix it. But I do want to talk a little bit about why it happens so the tl;dr version of this — is frequency.
[00:00:51] There are two primary power frequencies in the world. There’s 60 hertz in North America and 50 hertz in most of the rest of the world, and if you’re shooting with a 60 hertz designed camera, like the GH6 set into 29.97 mode, and you’re shooting in North America, you’re never going to have this problem. If you are shooting in the rest of the world and your camera is set to PAL 25 frames per second, you’re not going to have this problem.
[00:01:11] The problem with flickering lights comes from mixing the regions — when you take a camera that’s set for NTSC and you take it into a PAL region or in other terms, a camera that is set for a 60 hertz region and you take it into a 50 hertz region — or of course vice versa.
[00:01:26] So, the secret of how to fix this is actually pretty simple. There’s two things that can contribute to the flicker; your frame rate — that’s your 23.98 or 29.97 or 25 frames per second — or your shutter speed (or shutter angle). That’s your 1/30, 1/60, 1/90 of a second. So, one of those two has to be in sync with the frequency for the flicker to go away.
[00:01:46] If you’re in North America shooting under 60 hertz lighting with a 60 hertz set camera, then you probably never have to worry about it because your shutter speed can be anything, because your frame rate is already locked, and vice versa. It’s when you take a camera from one region to another that things get complicated. But again, it’s easy enough to fix.
[00:02:03] Now, I’m showing this to you here with this light bulb and we’re seeing the flicker very clearly on screen and you might be thinking, “Well, hold on a second. I’m in North America, shooting with a camera set to North American settings, with a light plugged into North American power. So, why are we getting the flicker?”.
[00:02:17] Now, this is kind of a funny little thing about this light. You see this light bulb right here? It is made by Philips. This is a Philips Hue light. Philips is a European company and as far as I can tell, there’s a chip-set in that LED light that is running at a 50 hertz cycle even though it’s plugged into a 60 hertz power source, which is really weird, but I know that YouTubers all over America have discovered this as they’ve tried to use these bulbs on their set and seen the flicker. So, if that’s you, you’re going to learn fix that really quickly.
[00:02:42] If it’s not you, then don’t worry about it. This is still the same demo that will teach you how to fix this no matter where you travel to. It’s just convenient for me to be able to show it to you in this demo. Alright, so take a look at the camera settings right now. You can see that we’re shooting at 30p, (it’s actually 29.97; the camera just calls it 30p), and you’ll see that we’re shooting at 1/60 of a shutter speed.
[00:03:01] Now, 1/60 while shooting at 30p is your standard. That’s pretty much where we want to be. That is the equivalent of a 180 degree shutter. If you’re shooting at 30 frames per second, shooting at 1/60 of a second shutter speed, that is considered “ideal” — but as you can see here, it’s giving us the flicker because neither one of those things are in sync with the 50 hertz refresh rate of that light bulb.
[00:03:21] So, to fix this, it’s really easy to do. All I gotta do is roll this from 1/60 down to a 1/50 of a second and look at that — the flicker goes away. That 1/50 of a second is in sync with a 50 hertz cycle. Easy enough. Now, hold on, there’s a lot more to this, so don’t go away quite yet.
[00:03:38] Next I want to move the camera over to 24p because you might be shooting in 24 — especially a lot of YouTubers like to shoot in 24, so let’s do that. With my GH6 here, I’m going to go ahead into the settings and change this to 24. Now you can see that I’m in 24 frames and I’m still at a 1/50 of a second shutter speed, and there’s no flicker.
[00:03:57] If I roll this up 1/60 of a second shutter speed, the flicker comes back. So, that’s exactly the same as 29.97. So, what’s the point of seeing this? Well, again, it’s to show that only one thing has to be in sync because I’m still in 1/50 of a second I’m still in sync with the 50 hertz lights. But now let’s switch the camera over to shutter angle.
[00:04:15] A lot of advanced filmmakers like to shoot in shutter angle, so let’s see what happens if we do that. The GH6 fortunately can do that easily. So, I’ll just switch over to angle mode, and now if we look on screen and we see that it’s at 180 degree shutter at 24 fps; that flicker is there. So, what are we looking at at 24p and 180 degree shutter? Well, that would be the equivalent of 1/48 of a second shutter speed, which when we’re in shutter speed mode we can’t actually get to. In shutter angle we can but look the flicker is back.
[00:04:44] So, we’re at 1/48 of a second which isn’t quite 1/50, so the flicker is there. So, how do we fix it? What is 1/50 of a second in shutter angle? Fortunately, the camera has that built in. One roll down to 172.8 degree shutter angle, and that is 1/50 of a second, and that once again, eliminates the flicker.
[00:05:02] One more thing I want to show you with this camera is switching it over to PAL mode. Now, I’ve shown you that at 29.97or 23.98, I have to keep the shutter speed or the shutter angle at a specific area to keep it from flickering — but if we go over to PAL 25 frames per second, then I should be able to go to any shutter speed or angle and not get a flicker. Let’s find out.
[00:05:21] I’ll jump into the camera and quickly change this to PAL mode. Now we’re in 25p or PAL mode and you’ll see in the settings that we’re at 180 degree shutter and there is no flicker. In fact, I can go to any shutter angle and there’s no flicker at all in there. Now, there is one thing that you might notice, especially as I underexpose the image a little bit — and that is banding.
[00:05:41] It’s not rolling but you can see some variations in light and darkness — kind of a banding showing up on there. That is because of the bulb itself and there’s often nothing you can do about it, except if it is a bulb like this Hue and you do have control over it, then set a color that is less reliant on multiple hues simultaneously.
[00:06:00] So, this is a purple light. It’s obviously using kind of the red and the blue together. If we shift it towards an almost entirely, or predominantly, blue color, then the banding will go away. It really is just about the bulbs and the quality of the bulbs and unfortunately, there’s not a whole lot you can do about it other than to change the color — but at least you know what to look for.
[00:06:18] Now, I’ll give you one more tip when it comes to finding this banding. Let’s say that you’re using lights like the Hue and you’ve got it on set and you built your setup, and you think that you have eliminated the banding or the rolling entirely. There’s one way to really, really check that it’s gone and that’s to record a couple minutes of footage and then scrub through it really quickly in your NLE.
[00:06:36] When you scrub through it and accelerate the footage, you will see any rolling that might be really slow and largely imperceptible. It’ll show up much more quickly and much more easily. So, if you’re not totally sure if you’ve gotten rid of it, shoot a couple minutes footage, scrub through it and make sure that it’s gone.
[00:06:51] Next up, let’s take a look at some LED buttons in tech products. This is the ATEM Mini. Arguably the most popular video switcher on the market today which means there are a ton of YouTube videos about this and unfortunately, that means a lot of those YouTube videos look like this.
[00:07:10] Now, the good news is that this is mostly just as easy to fix as it is with the Hue light and you’ll see what I mean in a second. First of all, you’ll notice that we are back in 29.97 at 180 degree shutter and of course the lights are flickering like crazy. All I have to do is roll that up to 216 degree and the flicker goes away. Well, mostly. There’s still a little bit there and you can really see it in the out-of-focus buttons in the background but it is for the most part gone.
[00:07:36] The problem is, it’s about to get worse because I’m going to darken the buttons so they look better on camera. Let me show you what I mean. The ATEM Setup app has a button brightness slider that allows me to darken the buttons, which if you’re shooting the ATEM, is really handy. So, let me darken this down until the hot spot goes away and the buttons look even better.
[00:07:55] Unfortunately, now that the buttons look good, they’re flickering even worse. So this is where Synchro Scan comes in. Synchro Scan is the ability to change your shutter angle by one degree increments. Now unfortunately, this is not a feature that you’ll find in every camera. It is however in the Lumix GH6 along with many of the higher-end Lumix cameras.
[00:08:13] First let’s go ahead and activate it. I’ll jump into the menu, turn on Synchro Scan, and you’ll see here that we’re starting at a 216 degree shutter — and there’s that flicker. Now as I roll the shutter dial, you’ll see that I’m changing it by one degree increments. Now, that’s the wrong direction because the flicker is getting worse but let’s go ahead and roll this up, up to 217, 18, 19… the flicker’s gone! I go to 220 and the flicker starts to come back. So, 219 is the sweet spot for this particular brightness setting that I’ve chosen for these buttons.
[00:08:45] This is again something you can only do with Synchro Scan where you have that single degree shutter angle adjustments. Now, I’ve got one more demo that I want to show you and that’s using another tech product that is going to be really difficult to find the flicker on but I’m going to show you a trick on how you can be sure that you identify it perfectly.
[00:09:05] The last example I want to show you is using this Accsoon Cineview HE wireless HDMI transmitter which has a little LCD display on it. That LCD display, as you can probably see through this camera angle, is flickering a little bit. Now, this is going to be a little bit more challenging than the ATEM buttons to get rid of but we’re going to use the same technique — but I’m going to show you a trick here.
[00:09:23] As you can see here, that flicker is really bad. I’m back at 29.97 at 180 degree shutter and it’s flickering all over the place and if I roll through my standard shutter angles at 216 or 240 and anywhere I go, the flicker is never going to go away. So, how do we get rid of it? Of course, we need Synchro Scan again. So, I’ll go ahead and activate that. Turn on Synchro Scan and from here, we’re going to roll through all the available options and just look for something that works.
[00:09:49] This is the hard part of this. Sometimes, you just have to try. Roll through all the possible shutter angles and look for the one that looks best. Now, I already know where we’re going to go at this. So, I’m going to take you straight to it. I’m going to go from 180 up to 222, 223, somewhere around there. You’ll see as I start rolling up here, the roll, the flicker gets less and less and somewhere around here we’re going to find something that looks pretty good. 222… like 221 has definitely still got a line… 223 has definitely still got a line. 222 is close, but if you look really closely, it’s not perfect. There’s still a — still a little bit of a roll in there.
[00:10:26] So, if we can get rid of the scan line mostly around 222 degree shutter, that means we might also be able to get of it around 111 and also 333. So this does go in even increments like that. So, I’m going to take it down to 111 and let’s see what it looks like there.
[00:10:44] And here we are getting close and 111, and it’s still not quite gone. We’re close there, but I want to show you something else that’s kind of interesting here. Notice at 112 the scan line is white — we’re seeing a white line there and as I roll past 111 down to 110, that line becomes black. It’s just a little indicator here that something has shifted and if you’re seeing that, it goes from one to another type then you know that what you’re looking for is somewhere right in the middle there and unfortunately here even at 111, it’s not quite perfect. It’s - it’s a - it’s close but it’s still, a little bit off.
[00:11:17] So, now let’s try 333. Now, as I get into 333, it’s a little over exposed so I’m going to darken the iris down a little bit now — and there, I think we found it. You might still identify a very slight flicker in there but we certainly have gotten as close as we possibly can at this point. So, that’s the tip. When you find a number that’s… oh, so close but it’s not quite right, do the math on it and figure if you can cut it in half and go the other way or double it or cut it in half and then double it — you get the idea!
[00:11:48] Find the variations of that, that might work. It gives you a starting point, and then just go somewhere around there. Sometimes, it’s just what you gotta do. It’s a little bit tricky but it’s how you do it. Now, there’s one more extra little bonus tip in here. You might have noticed this when I was showing off the ATEM buttons. Anything that is out of focus will likely show the flicker worse.
[00:12:07] You can see in this clip that we did earlier of the ATEM buttons; how the button in the rear is defocused is definitely exhibiting more of a flicker than the one in the front that is sharp. So, that’s your final tip there. If you are having trouble identifying the flicker, try defocusing the camera a little bit and see if that helps to exhibit it a little bit more.
[00:12:25] Now that I’ve shown you these three tips, you should know how to be able to find and eliminate the flicker whether you’re traveling and shooting travel videos or shooting tech videos at home. Next up, I want you to check out this super nerdy, geeky, math heavy video about why all of this happens because frankly, it — it’s kind of interesting. I’m PhotoJoseph. Don’t forget to like and subscribe and we’ll see you in the next video.
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And I have it off on my phone, but others could potentially have issues with variable refresh rate maybe...?
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