Human Vision vs The Camera
If you were to take a photography class through other instructors you're going to be taught about shutter speeds and apertures and composition just like we did because it's all really important fundamental stuff but kind of with this last final section I want to look at kind of how we look at the world how are cameras see the world and really understanding the differences between those two will help us choose better subjects and figuring out what's actually going to turn out in a still photograph versus things that we can see with our own eyes but won't come out in a still photograph. And then I'll also have kind of some final thoughts as to putting everything together that we've learned throughout this class. So the photographic vision section is really about developing the photographer's eye. Knowing what's going to make a good photograph by just simply looking at it. What we're going to do is we're going to be looking at how a camera works, we're going to be looking at how our visio...
ns works and we're going to be looking at how we are deceived in many many different ways by what we think we see isn't exactly what's really there. So first off we're going to be going through this comparison between human vision and the camera. Alright so we're going to start off with some illusions and I'm guessing some of you have seen similar illusions before. When you compare the red line and the blue line does one of those lines appear to be bigger than the other line? In most cases people are going to say the blue line looks bigger than the red line when in reality it is exactly the same size. But because of the background and the lines back there and what we kind of, our brains like to put this together it's like a puzzle we are solving. We assume that it's larger because of the background and so what this means to photographers is that the background matters, it's not just your subject, it's everything around your subject affects the way that your subject looks. This is another version of it, which line appears larger? Well as you might guess I'm playing a lot of tricks with you here, they are exactly the same size but the other subjects around that particular object make it look a certain way. You probably see four black dots on the screen. You probably see a white square on the screen and this is once again our brains are trying to solve a problem. There is no white square, alright, there is corners for what could be a square but it's not a square, our brains just want to connect the dots. We like solving the problems here. Alright so I am going to have an audience participation question for you and I have three different roads here and one of these roads is different than the other two. Remember our Sesame Street game? Which one of these two roads is different? So I'd like you to raise your hand if you think A is the different road. Anybody think A is the different road? Nobody, how about B. Does anybody think B is a different road? Okay we've got a few people on that. Who thinks C is the different road? Okay, the majority of people think that. Okay let's compare these. A and B are different so one of these is off here, A and C are exactly the same. The one that's different is B and only a minority of you got that right. And so subjects near our subject and their angles of view are going to affect the way that we see things because we have a certain perspective, we expect things to look a certain way. In this case we have straight lines. When we add these blocks in between it's no longer looking like it's straight lines. I mean for me this reminds me of the Donkey Kong video game, you know, lines going up in different levels and so forth, kind of confusing, hard to look at. Alright so I'm not playing any tricks on the screen here with you this is just a middle tone gray stripe. But if I change the background to a gradient and you look at that stripe left and right it appears lighter on the left and brighter on the right and that's because your eyes see this is as white and then it sees this as darker. And so if I was to flip it around it doesn't make any difference it's always going to appear lighter on the left because of the dark background. Alright, so we have a square with A and a square with B. Now C is exactly the same tonality as one of those. Or both of them, what do you think? Would you believe it's exactly the same tonality as both of them? We associate one color with other colors, it looks like it's shading so we think it's going to be one thing, in reality B looks a lot lighter but it's not. Alright I know some of you like puzzles and so I have a visual puzzle for your. Let me put it together to start with here. So we have a colored triangle. And notice where the corners are at, okay? And take a look at those puzzle pieces and we're going to move things around and create a slightly different triangle. Very very similar but now we have a whole extra box and I don't know why it's playing so quickly here. But we got an extra box in there. Does anyone know why we got an extra box when we moved it around? Very hard to figure out because it just seems like everything just kind of moved around a little bit and the trick is, is that this is a straight line and the angle that you see here is not exactly a straight line and all those slivers essentially added up to an extra box. And what that tells us is that as humans we tend to be very good at judging vertical lines and horizontal lines but when it comes to angled lines we're not nearly as good as telling if it's a straight line. Alright, going to really mess up your vision here. Alright so on the left we have a color coming in and the right we have a new color coming in. Do these look, do these appear like they are the exact same color? They are indeed exactly the same color. The colors around it associated with it fool your eyes into thinking that they are one color or the other. And they seem vastly different to me. And so using the same concept here these red dots, these red squares, where do they appear lighter and darker? And it has to do with colors that are associated around them, they're all exactly the same but when you have a subject around a darker item it's going to appear lighter, when you have something around a lighter item it's going to appear darker and so subject matter, background matter, matters. Alright I need your full participation on this one I want you to stare at the white dot, alright, just stare at the white dot and what's going to happen is the retina is going to get saturated with colors in your eye and I'm going to have that white dot move down to those photos and you're going to see something kind of weird in those photos and let's go ahead and start moving it down, keep your eye on the dot, keep it on the dot, and keep it on the dot and my guess, you're seeing some weird colors with those photos that don't have any colors, alright? Alright so the next one, and this one is maybe the most interesting of the ones we're gong to do. I'm going to show you this photo in a moment but we're going to look at first is we're going to look at this photo and I've put a little X right there in the middle I want you to stare at the X in the middle and so you're going to be looking at the reverse colors of what this is supposed to be. As these colors get saturated on your retina you're going to have a negative afterimage. And it's going to be the positive of this image. Now when I go to a black and white image if you continue to stare at the black square you can hold this color image for quite some time but if you look away you will lose the color image. Alright so everyone's been looking at it for a good 15 seconds let's go to the black and white image and stay in the middle and you should be able to hold that color and then after a little while look away and then bring your eyes back on to it and it's a black and white image. So that is called color persistence, it is a negative afterimage and so it's one of the things that our brain does in the way we look at images and it's very awkward. Okay so we have a little bit of a participation game in this next image alright? It's not just an image it's a graphic and what i want you to do is I want you to follow the basketball with your eyes and I want you to count the number of times that it bounces against one of the black boarders. Okay, everybody ready? Now just count it to yourself quietly, silently. Okay now I don't care how many times it bounced, who saw the word? We got one person, raise your hand if you saw the word and so you're so busy counting it's hard to pay attention to other things and what actually happened is I had the world tripod run across the screen while that was all going on to see if you could pay attention to that. I think the number was 22 in case you were interested. But the thing is is that we can only, the multitasking, we're only so good at multitasking. And so there's a lot of things going on and we get tunnel vision at things that we are looking at and we kind of block out a lot of other things that are going on that we would normally pay attention to. And I based this off a video, they had a gorilla that came through a scene if anyone's seen that video the gorilla comes through and so I totally did a ripoff of that in my own version without the trademark gorilla in it. Alright so let's compare a human versus a camera. And so first let's talk about human vision and the way our own eyes work. And we talked a little bit about this when we were talking about lenses and what was a normal point of view. And so we kind of have a 5mm lens where we can see everything in front of us because we can see so much there. We have a 2500mm lens when we're reading, we can see very detailed information in a very small area but the central retina gives us a pretty normal 38mm lens and so we kind of have to think about this when we see the world around us. We get to see wide angle, moderately wide, but then if we want to be able to read a clock from a far distance we can still see it. Because we concentrate and we look at those little details and it's a little different than a zoomed lens. But we concentrate in different ways. One of the things about humans is that we look at motion in many ways. And so this is a slow shutter speed shot but when we turn it into a video that way our eye looks at this and what we look at in the frame is very different than when we take a still photograph. And so one of the things that attracts humans is motion, you know, whether it's the tiger in the grass or a car coming down the street things that move are kind of more interesting intrinsically to us but they don't show up nearly the same way when we take a still photograph of it. I mean it's kind of a nice photograph in some ways but when we look at a video of it it changes dramatically how we see that subject and what we think about it and so really think about anything that's moving you've got to start translating how is that going to look in a still photograph because it's different, very different. I have no way of visually showing you an example of 3D, just look in front of you at something other than the screen. 3D is what we get to experience with our two eyes, we don't get to use that with monitors and prints and so forth, it's two dimensional and so we don't get that same sense of depth and so it's a different type of depth that we get when we are in photography. The light range that we can see is limited in our cameras, we've talked about it, we've talked about HDR photography and we can shoot silhouettes but that's not really how we see things with our own eyes in most cases unless it's really, really extreme and that's because our eyes, it's not that they have that much greater range than the cameras, it's that they're constantly adjusting. When you look up to a bright area your eyes adjust for the bright area. You look down into the shadows, they adjust for the shadows. If you've heard about night vision, not talking about any sort of device that you buy just your own natural night vision, if you want to go out and look at the stars you should go outside at night and you should wait about twenty minutes and don't turn on any lights because it takes about twenty minutes because the actual chemicals in our retina will change allowing us to see under low light better and so there's many different ways that our eyes can adjust for low light levels. The color range, we talked about this when we were talking about white balance and the color settings in your camera. Cameras in jpeg are set to SRGB, we can shoot raw which is Adobe RGB. when we use post production software like Adobe Lightroom we're going to be in Prophoto RGB but that is still not as great as what we have with our own eyes. We have a greater color range and when we get to areas where there is really temendously saturated areas of color it's going to be hard to replicate that in a photograph and I've found that when photographing flowers. There's just really, really saturated colors, hard to represent with pixels. The curved lens of our eye and the curved retina can cause a problem because our lenses are curved if you look at the front of the lens but we have flat film planes. I've seen some patents where companies are looking at doing curved sensors at some point in the future but it doesn't exist now and so right now there's going to be a bit of a problem whenever we're trying to deal with certain kinds of subjects. And this can be had when you're looking at maps, the Mercator projection of a map is a very very misleading map because it makes areas in extreme areas like Greenland look much larger than they actually are. In this top map it makes Greenland look the size of South America whereas Greenland is really actually the size of the Saudi Arabian peninsula there. And so it can be very deceptive when you're trying to transition from a circle to a flat object. And so when you're photographing a building and you do it very much straight on in a symmetrical manner you're going to get straight, parallel lines. When you're off to the side those lines are no longer going to be parallel. Nothing you can really do, that's what happens when you're not photographing straight on but our curved retina doesn't really see this because of the unique system that it has. When we put a circular object off to the side with a wide angle lens it's going to distort it but it won't do that with our own eyes because of our curved retina. The brain filter, it makes us just think differently about what we see. You might see an animal out there and it might seem pretty close to you because you concentrate on it with that 2500mm lens of yours, I saw it, it was right there. How many times have you seen the moon rising over the horizon, it's like did you see the moon today, it was huge. It's like, no, it's the same size that it always is. And even if Earth moon distance is traveling and the whole super moon thing it's not that much difference. You can still completely block it out with your thumb at arm's length and so sometimes those elephants were so close, they were right there. No they were a pretty long ways away. You know you'll see a bird and it's kind of behind some bushes and twigs and stuff and your brain is just looking at the bird, your brain is not thinking about the twigs and so forth and then you take the photo, oh wait I had a bunch of stuff in front, i didn't even think about that stuff, I was just thinking, so concentrated on the subject, your brain knows how to filter out things that aren't important so that you don't think about it. So those are some of the advantages of our human eyes and our brain's interpretation of what we see. So let's talk about some of the advantages of the camera, what do we have with the camera that we can't see with our own eyes, and all of these I think are good techniques, tools, and tricks when we want to show somebody in a photograph something that they can't see with their own eyes. And so yes, of course we can see birds flying but can we count the tips on their wing that easily as we can in a frozen photograph? And so any time something is moving quickly that you can freeze it, that's going to be intrinsically interesting at least to a certain degree jus that aspect of it alone. The exact opposite is true too, this is not a real representation of how a river looks. So for documentary purposes I have failed in these photographs but as far as an artistic interpretation for a view of this one particular place it can work out very well in that regard and so thinking about things, how they move and how they might look with different shutter speeds is going to show people new things that they don't get to experience with their own eyes. We can have infinite depth of field with stopping our apertures down, with special techniques, focus stacking, with tilt shift lenses we can have everything in focus where in reality not everything is in focus with our own eyes. If you don't believe just hold your finger up in front of your eye, about a foot and a half away. Focus on your finger and if you're looking at me I'm going to be out of focus. Put focus on your finger. You can't focus on two different areas with your eye but your eye adjusts very quickly, you do have a very quick focusing system but you can only focus in one spot and so we can use that in photography to our advantage. We can have shallow depth of field as we've talked about, doing our portrait photography with our aperture wide open. And that allows us to tell a certain story, have other subjects in the frame but have them diminished in importance because they're not as in-focus. Yeah, you might be able to see a bird that's not too far away with your telephoto eye that you can see, that 2500mm lens but you can't really get in and see the details really really closely. And so for subjects that are farther away using that telephoto lens is going to get us closer on those subjects. The compression effect is a unique thing that we've talked about several times in this class and it's a great way to tell a particular type of story that isn't quite the way that we see the world with our own eyes. Getting very close up, I'm not sure what your personal minimum focusing distance is but mine used to be right about here and it's getting a little bit longer as the years go by out here but we don't usually look at the world in this macro way and so getting really close up with a lens is going to give people a view of a world that they don't see on a regular basis. We do have a pretty wide vision with our eyes but we don't have real sharp vision off to the side. You know, I can see my hand moving way over here but if i pick up a piece of paper I can't read anything over here, and I can't read it, read it, read it, read it, until I get around over here and I'm actually looking straight at the words. And so now we can have sharpness everywhere inside of a really wide angle view. We can get cameras and we can mount them in really unusual places. We have small, really portable cameras. There's a lot of mounts, you can get your camera in places that you can't normally see. You know I was at a market stall and it was all closed but I thought you know there's some nice symmetry everything closed off, but you know what, those openings are big enough for me to stick my lens through, I can get my lens through there and I don't need to see that. Where with my own eyes I'm sorry, that's the only place I could put myself. Leaving the shutter open on our cameras can really allow us to work under extreme low-light conditions and our eyes are pretty darn good under low-light conditions but there's even more that we can see when we leave that sensor open and exposed to light for long periods of time and so we'll be able to pick up quite a bit of information in that regard. One could argue that black and white images are simply Photoshop tricks. If, you know, we didn't have that whole history of black and white film it's just a Photoshop trick. Very few people are color blind and so this is not the way that we see the real world, this is an artificial way but due to the history of photography it's a traditional way that a lot of people understand and get and it's a very good thing and we'll talk a little bit more about black and white photography because I think it's important, I think it's a great tool for a lot of different types of work. Flash photography. Unless you walk around with a headlamp on all the time we don't get this extra light shining in on our subject. And so adding a flash to our subject is going to make it look different than the real world. Sometimes better and in a different way so it can be very helpful in many situations. We can use a number of filters, this one being the polarizing filter. It's not exactly how we see the world but it's a trick that we can play with our cameras and lenses. Reducing those reflections. In this photo I shot with a fish eye lens. There was just a few too many people right there in the edges, remember I talked about those little intrusions on the side and so you know let's just crop that in, get those people out of there and now you have no idea how close those edges, those balconies are there. And so you can clean up a lot of stuff by going in and cropping your images and getting rid of just things that might be there but just a little out of the frame at this point. And so if you don't want some little intrusion or a little thing on the side of your frame you can go ahead and just crop it out and nobody would know that it's ever there. And so that's a real important tool that you have in the cropping phase of your images. And so in pure numbers we have a lot of advantages with the camera, they're just different though and so they're different devices and you have to consider that when you are shooting your photographs and I've seen people who are photographers and they're trying to shoot photos like paintings, or they're trying to make their photo look like a sculpture or something like that. And it's a good challenge for yourself but in many aspects you really gotta play to a camera's strengths. Think about what a camera is good at and that, if you're trying to create art with that device that's what you're going to be able to create that's unique and different than anything else, than trying to mimic some other device that records something else or is a piece of art and so I always try to just think of everything that I can do with the camera that's unique and unusual and play to that to really play that instrument as best I can.