Waveforms and Scopes
Here's what this monitor really does that is pretty amazing. It allows us to check exposure and it allows me to pull up what's called a waveform monitor. So if I pull up a waveform monitor, it's gonna show me where my exposure is. Now in this exposure, I can see that I'm overexposed because, yeah I can see that I'm slightly overexposed based off the levels of target. Where the levels of that target is sitting. And right here, it's important because now I know that if I actually jump down this exposure slightly, I can get my scene within latitude of exposure. Now I'm going to explain what these forms and scopes mean right now. The other powerful thing about this thing is also something called a vector scope. A vector scope is crucial because it tells me where I am in white balance and it tells me how saturated I am in relation to where that center point is. Okay, so these are things that may be so daunting and scary when you talk about it, when you look at it but again, I didn't know ab...
out these three years ago. I still was doing content. I am only telling you about it now because I think it's important for us to learn about what we call waveforms and scopes. Okay, so a waveform, confusing, really, really confusing but it's a great way to visually check yourself on set. Because there are some things that sometimes we just don't know where we're at and we've just got to check the overall scene value as opposed to just the exposure of the person. So, waveforms and scopes are And I'm going to give you guys a clinic on it, so we're gonna learn about these right now. It's my favorite part. So, this is what we call a waveform and in this specific format it's called an RGB parade, red, green, B, parade 'cause they're coming after each other right? Like a parade. How much black or how much white. Meaning, am I overexposed or am I underexposed? Okay, you guys follow me on that? I'm probably going to get hammered on this, the proper term is luminance. Holes on the lines here. So we read a waveform based off of zero to 100 IRE. And IRE stands for Institute of Radio Engineers I think. And the reason that plays into affect is because all this does is measure amplitude and we can discern the level of video signals by finding out their amplitude as they come through this waveform monitor. So, black is at like 7.5. So this may be kind of confusing right now but if you look at a chart, if you look at... This chart, what do you see? You see black, you see gray, you see white. Black, gray, white. Can you see what I mean? Black's at zero, gray's at 40, white's at 80. Am I on exposure? Yes I am. So here's how it looks moving forward. It's always going to show left to right. If you have a chart this way, they're gonna stack up. So you can very easily tell if you're one, white balance 'cause if you're white balance, all three colors will be right on the same IRE level. If this was shifted up, what would I be? Mid tones? Red mid tones too high. You follow? If this was shifted up, what am I? Green mid tones, too high. If this was shifted up, green shadows too high. Got it? So show the chart like this, not like this 'cause it gets very confusing this way. (audience laughs) Don't do this, alright? Hey look! How do you read a waveform? It's always left to right. See, it's always left to right. But this is the left side of the frame and the right side of the frame. In this areas it's the left side of the frame and the right side of the frame. So here, left side of the frame, right side of the frame. Black, mid tone, highlight. Here, middle, black, mid tone, highlight. On the right side. Here, black mid tone, highlight. You kinda see it? So when you actually look at something that's why you can't do it like this. It makes it difficult for you to see where your black and your mid tones and your highlights are. What does this mean? This is a real scene. Where's the chart? The charts here. If I'm only looking at this part of the screen, where's my target? The target's here, here and here. Black, mid tone, highlight. What's wrong with the image guys?
They're all blown out.
Blown out! Over! I need to bring that down, I need to bring that down, I need to bring that down. So my shadows, mid tones and my highlights must come down. Can you see how this is valuable? Can you see how it's valuable? It's a real time test on your exposure. So what do we do in post? We do this, we can bring these values down in post. We can bring these values down in production, before we get to post. That's the power of a waveform monitor. It's a second level check. Because let's pretend I've got a screaming background and it's just super hot, just completely overexposed. If I only meter for the subject and couldn't run to the background to meter it, that waveform monitor allows me to leverage both the meter and the monitor to get the right exposure. You follow? Because I can see behind it with the monitor and see where the specular highlight falls. If the behind it falls higher, I can bring that down in the way of camera exposure. So I think I talked about using a waveform monitor right? Any questions? I know that was really, really fast. (audience laughs)
Victor, not a question but just a quick like, that for me was one of those what I call "pause moments." Where it's like okay, I think I got that 'cause I understand exposure from photography but that is such the importance of having this class to be able to go back, understand, re watch, all of these things for those pause moments like that one.
This is my favorite part in making this class was doing this section because it's so scary. And we're not done yet, we still have vector scopes. What's up?
Yeah, forget production, let's do a post production. When you're in post production, how are you adjusting your white balance to get it where it needs to be?
Excellent! So in post, I'll show this later in the class,
Is that Adobe Premier?
This is Adobe Premier. So you can do this in Adobe's Lumetri Color. Lumetri Color module or you can do it in Da Vinci. I chose to do it in Da Vinci and I'll show you how I did it. Basically, what you end up doing is in the previous slide here, we saw that the white value if definitely off white. So what you do is isolate the red channel inside of a three way color corrector and you bring down the red so that you can then match it in post to that, to get a natural color tone. And we'll talk about that in Da Vinci. And the best thing about Da Vinci, it's free. 12.5 is free. It's always free, it's great. So we talked about light-meter vs. waveform and how we can leverage both. Did you guys understand the concept there? I really wanna make sure we understand that because I can get an exposure value here but if I can't run to my background, the waveform monitor's gonna tell me if my background's out of gamut or not. That's huge! Because what matters is what I'm seeing on a screen and if that IRE value clips up and jumps up, I can pull down my camera exposure to make sure that I'm within latitude and it's between 80 and 7.5. 40's your mid tone. I see some heads nodding. (audience laughs) I love teaching, this is great. (audience laughs) Okay, cool! They do separate things, best used together. That's what you gotta remember. The more the cluster of light, the more the cluster of colors shifts away from the center, the more off white balance you are. Now, I'm gonna get my trusty teaching tool here. From center to out. That vector is the level of saturation in what is the here, the scian channel. If this line is straight from here to here, that means I'm on point with the color. That means I do not have a hue shift. If it shifts this way, that means I have a hue shift. You can see here, the colors are actually pretty far out. What that means is the further from the center the colors are, the more saturation you have in the image. How powerful is this tool? You can look at it and immediately tell that your blues are over saturated, they're shifted in hue and then you can see that there is no white balance somewhere, 'cause if there was a white balance, you'd see a white cluster somewhere right here. Let's keep talking. So here are the colors. You have one other vector that's really important called the flesh tone line. That's where you're gonna get clean flesh tones. So this is a really powerful tool and I'm teaching it to you guys now so that later on when you step into it you're not scared by it. People get really, really scared looking at these kinds of things. It's really not that bad. Alright, so the image on the left, skew towards blue. But as we take a look here, "Hey! This is what the chart's for." You show the chart, boom! The perfect white balance. Boom! Perfect color! Everything's on vector, except that green. It's slightly shifted. Now you can look at these scopes for two different cameras and begin to see in which way you need to shift in post to match them. Or use this target in post, use it in Da Vinci Resolve and Da Vinci Resolve will match them for you. Huge, huge huge! And yes, I'll teach that later. So that was a gear component. Obviously I didn't talk a lot about gear. What'd I talk about? The one thing I that I think is gonna be important for you as you progress into doing client profiles. Because vector scopes and waveforms are going to be something that's gonna save you because as cameras evolve and as you evolve, your knowledge base of the fundamentals of filmmaking and the fundamentals of just understanding how to read something is gonna play huge. 'Cause it's gonna prevent you from making a mistake. These are obvious things we do every time before we shoot. Because a white balance, you can't replicate. I didn't get white balance on some of the shoots and I spent hours grading. It sucked.