The Science of Light
Alright, so we are going to pop on now to the science of light. Alright, so this sounds potentially a little scary, and who wants to do science with light. I mean, I was a little bit of a nerd in high school but like, not enough to be like, yeah, lets do science. So I'm going to do the science of light without getting science-y; we're gonna do real basic. And the reason you need to know this is because if you understand the science of light, and this is just a quick description, you know that, oh, that could either be a small modifier really close or it could be a really big modifier near by, like it gives you some options of how that person with that photo might have lit it. There's a couple different things. So lets look at the one important rule of science we're going to talk about. So this first rule is: the larger the light source is relative to the subject, the softer the light. And then conversely, the smaller the light source is relative to the subject, the harder the light. Th...
e reason that you care is this. If you look at a photo and that light you can tell its really soft, its really soft light, it could be two things. If you look at that first thing, if you want softer light you need that light source to be larger relative to your subject. So what that means is I could take a smaller light source and bring it super close to her head, 'cause now relative to her its very large. So it'll become soft. But similarly I could have a big Softbox back here, 'cause relative to her its actually still pretty big. So as you're checking things off you could say, "Okay, this is either, for this soft light, its either a really big light source that's maybe a little bit away, or its a smaller one but they brought it in super close." Its one of the two. But then you're gonna use your other tools, like looking at the catch lights and other things like that to have a guess of which one it actually was. Now conversely, same thing. A hard light could be something like a zoom effector or something that's small, like actually small, or you could take something like this and move it to the other side of the room, 'cause now, relative to her, its actually pretty small when you move it away. So you gotta figure out which someone did. So here's my illustration of how this works using natural light. So in this example I've got my subject outside on a sunny day. And so I can already tell looking at her face that is super hard light; that transition from highlight to shadow is razor sharp, and if you look at the highlights on her face, I mean, they're blown out in texture, I know its hard light. Well we know that she's lit by the sun; its a sunny day. The sun is technically huge, but relative to her its so far away that its actually a pin prick, its tiny, so its relative. Okay, so we know, hard light, sun really far away, you can see that. What I can do is I can actually change this entire look and feel by popping up a diffuser. This is a 30 inch diffuser nice and close to her. But what happens is that pin prick, that small sun relative to her, very far away, very small, when it hits that diffuser it becomes the diffuser. It spreads out. The diffuser becomes the light source, and because its 30 inches pretty close to her, now relative to her, its actually pretty big, so its softer. Yeah.
Uh, I'm just curious, you said it was a 30 inch diffuser, is it one stop, or?
This is the one, its probably like a one stop or maybe even more than that, and it was just a regular three in one reflector, so it had the silver on one side, the gold or white on the other, that kind of thing. The other solution that I use, if I want light to be even softer, and this is soft, like that's a beautiful transition on the cheek; if I want it to be even softer I can move the reflector closer, the closer I bring it in to the face the larger it is relative to her, or I could use a bigger diffuser. Now a couple other solutions if you wanted to do this, what they do in big commercial productions is they set up big tents. Its this massive tent of diffusion; so basically they're in a room lit by light on all sides. Or they use something called a scrim, and a scrim is a fancy word, its basically like a bed sheet on a frame, but they're more expensive and you can do different stops, right? You can do quarter stops, three quarter stops, on and off stops, and by the way, that word, what we're saying there is how much of the light does it cut out. When it hits that diffuser, how much light are you losing in exposure from direct sunlight? So just so you know, they make the scrims, and like, Westcott makes Scrim Jims that are six foot, and they make eight foot square ones, but the solution that I love and I do this all the time on location, is Westcott has a seven foot shoot through umbrella. So if I go out on location and I open up this umbrella right next to her head, that is like a seven foot massive Softbox right next to her head, and I converted the really harsh sunlight, and its only like, 99 dollars, its very inexpensive and its a good solution for that. So the key here that I really wanted you to notice is watch that transition on her face, and all that is is popping up that diffusion. So the key is its relative size, but there are things you can do to make things relative size; move it in closer, or pick a different modifier. So here's how it works in the studio. If we're taking a look here at her. This is with a four by six Softbox, and if you look at the transition on the side of the nose and the cheek, its very, very smooth, its very soft light, if you look at the highlight on her forehead its very smooth as well, its not very specular. And if you look at her catch light you can see over there, you can actually see the shape of the soft box, we're gonna talk about that later. When I switch over to an Octobox in the exact same position, the same distance from my subject, the light gets a little harder. See how those shadows get more crisp? The transition isn't quite as smooth. There's not one right or wrong, but just know, its only because that light source got smaller relative to her. And then there's a little bit more texture on the forehead. Now let me show you one more variation of this. Okay? So we're gonna look at the relative distance thing again. I can take that same Softbox super duper close, nice and soft, really subtle transition on the cheek, or, I can back it out. The light becomes so, so much harder. Look at the reflections on the forehead. There's a lot more texture when its far away, 'cause relative to her, its small, and therefore its harder. Or look at the shadow cast by the nose and on the cheek bone. It just becomes a much harder light source. So just keeping that in mind, you look at a photo and you go, "That's kinda in between hard and soft but I think its a little bit hard, its probably, is it further away," like its giving you some things to check on your checklist, and one of the things I'm looking at, we'll take a look at is the catch lights later. Just real quick look at the catch lights between these two. This is giving us another secret. You can kinda see the catch lights changing as well as the quality of light. When its far away the catch lights small, when its close, its big. Its giving the idea, okay, its actually a bigger light, or its much closer. Okay. And so this is taking a look once again at the texture there. In the example where I've pulled that light away, smaller, more textured. So that is the one kind of weird part of the science of light that you will have to know. So I'm gonna pause for questions, see if there's any over there, and then I'm gonna show some demonstration of all of this in action. Okay, let me see if there is anything.
Sure, can a modifier be too large for a light source?
Yes, and actually, John Cornicello over here has a really interesting blog post or two. The question was, can a light source be too small for a modifier, can a modifier be too big?
Oh, okay, yeah, sometimes using the seven foot umbrellas and you have a small source like a camera strobe, it only fills a small part of the umbrella so you're only getting like, two feet of umbrella out of the seven, so you need to get some sort of diffuser on the front to fill the umbrella.
So the reason that this is going to be relevant to you is like, alright, you figure it out and you're looking at a photo as we talk about this later on and you go, "Okay, its a soft light source and I can see in the eye, yep, its an umbrella, and its super soft so its gotta be a big umbrella." and then you're shooting and you're shooting and you're like, "Man, this does not look anything like this photo, but I know, I can see it in the eye, I can see it in the quality of light, its a big umbrella, why am I not getting it?" and that's the point is, if you've got this big umbrella but then maybe a little speed light, when it hits the front of the umbrella its only lighting just a little bit part, so relative to her its actually still kinda small. So this is why the more you learn about lighting the more you check off, like, oops, I did that wrong, what can I do to get closer. I can take another one.
Okay, yeah, this is not totally a lighting question but lighting will effect it, Ricardo is asking, "Hi Lindsay, I love how you light your subjects, can you explain something about the camera angle, eyes level lower or higher from the subject?" So do you always shoot right at eye level, how does light effect that?
Okay, so here's a couple things. Can I have you facing me straight on for a second? This is something that you'll kinda see when you're playing around with catch lights. Your subject's angle of their face will make a difference because if all of a sudden she lowers her chin down, she actually starts to lose her catch light. The light didn't move at all but I'm making the shadows more defined because this is an equivalent, if I move it down I'm making the light appear to be higher, or it acts as if its higher up. As far as camera angle this is something that you want to be careful of, you can shoot so many camera angle, and this is one of the things they talk about in a posing class and I'm gonna give a little plug. This upcoming February I have a book coming out about posing, and one of the things I talk about is camera angle. So what you wanna know is, if I photograph from a high camera angle, up here, what's closest to the camera looks largest. So when I'm up here her eyes will look larger, and so sometimes its really nice 'cause you get this beautiful connection with the camera, but the downside of that, and I might need, can I have a 24-70? I'm a little short, or an apple box, we have apple boxes, I can do apple box. I'll take a quick demo of this. So this is less lighting but its hiding for you. Alright, perfect. So if I am on this apple box at a high angle, okay, look right at me, perfect. Her eyes are gonna look really nice and big, but what you will see is you'll see that her neck looks very short. Perfect. So see how short her neck looks? Its not necessarily a bad thing, but you have to know that that's what's happening. When I'm shooting out on location and I'm shooting with like, an 85 1.2, if I get up at a high angle and shoot down, I don't really care if the neck is short because its out of focus anyway. Like I'll shoot, really narrowed up the field. Conversely, if i come back here and I get down a little lower, or a lot lower, her neck is going to look so much larger. So lets pop this over. So take a look between these two. I mean, its night and day. In the first shot her eyes look much bigger but her neck is lost. In the second shot her eyes look much smaller but she has a longer neck. How this can relate to lighting is you might have the light perfect, like you get it all perfect and its what you want, and then all of a sudden, can you bring your chin down to me, bring it, 'cause I want her eyes to be closer to the camera, all of a sudden, if she brings her eyes down, I can get to the point where the eyes start to get really, really dark. So you can start to, and its still not too bad, depends on how high the light is. So when I'm looking at other peoples photographs that's something else I'm paying attention to. 'Cause if the model or the subject is posing like this, right? Chin buried into the shoulder, and their eyes are glowing, probably means I've gotta have that light a little lower in order to actually fill in the eyes. Where as as soon as she lifts her chin back up the light on the face totally changes, so its like, when you look at the photo you actually have to pay attention to the pose, left and right, and chin up and down.