1 00:00:04,400 --> 00:00:07,760 Speaker 1: Welcome to tex Stuff, a production from I Heart Radio. 2 00:00:12,200 --> 00:00:15,160 Speaker 1: Hey there, and welcome to tech Stuff. I am your host, 3 00:00:15,320 --> 00:00:18,840 Speaker 1: Jonathan Strickland. I'm an executive producer at I Heart Radio 4 00:00:18,920 --> 00:00:23,600 Speaker 1: and I love all things tech. And today's topic goes 5 00:00:23,720 --> 00:00:29,040 Speaker 1: by many names like chroma key, or blue screen or 6 00:00:29,160 --> 00:00:34,040 Speaker 1: green screen. The inventor of this technology developed it for film, 7 00:00:34,159 --> 00:00:39,400 Speaker 1: and that pun was an intentional you know, developed for film, 8 00:00:39,440 --> 00:00:43,120 Speaker 1: But I'm gonna I'm gonna run with it. Today we 9 00:00:43,600 --> 00:00:48,240 Speaker 1: use this technology and film in television, on Twitch streams 10 00:00:48,280 --> 00:00:50,879 Speaker 1: and zoom calls, I mean all over the place. And 11 00:00:50,920 --> 00:00:53,640 Speaker 1: in the old days, you weren't likely to encounter a 12 00:00:53,720 --> 00:00:58,360 Speaker 1: green screen unless you were inside a movie studio, like 13 00:00:58,800 --> 00:01:01,639 Speaker 1: inside a sound stage. But today there are a lot 14 00:01:01,680 --> 00:01:04,000 Speaker 1: of folks who have a green screen just stashed in 15 00:01:04,040 --> 00:01:07,880 Speaker 1: their home office. So today I want to cover this technology, 16 00:01:07,920 --> 00:01:11,680 Speaker 1: it's history and development and how it works. Now, before 17 00:01:11,720 --> 00:01:14,679 Speaker 1: I get into the history, which, as I'm sure most 18 00:01:14,680 --> 00:01:17,840 Speaker 1: of you know, is my moodus up a ran dai, 19 00:01:18,640 --> 00:01:22,520 Speaker 1: let's give a quick overview of what this technology actually does. 20 00:01:22,680 --> 00:01:26,399 Speaker 1: So basically, it's a system that allows a creator to 21 00:01:26,760 --> 00:01:31,720 Speaker 1: insert images, typically a background. That's your standard use of 22 00:01:31,760 --> 00:01:34,759 Speaker 1: this and you do it into a shot that otherwise 23 00:01:35,400 --> 00:01:38,640 Speaker 1: isn't actually in that location, so it could be a 24 00:01:38,640 --> 00:01:42,160 Speaker 1: static image, or the new image might be in motion itself, 25 00:01:42,200 --> 00:01:45,119 Speaker 1: so it might be video or film. This technology allows 26 00:01:45,160 --> 00:01:48,000 Speaker 1: creators to shoot in locations they might otherwise have trouble 27 00:01:48,080 --> 00:01:50,920 Speaker 1: getting to, like the bottom of the ocean, or in 28 00:01:51,000 --> 00:01:54,840 Speaker 1: outer space, or in my old college dorm room because 29 00:01:54,880 --> 00:01:57,520 Speaker 1: I was notorious for locking myself out. So when you 30 00:01:57,560 --> 00:02:01,400 Speaker 1: do it well, it really enhances us scene. But when 31 00:02:01,440 --> 00:02:05,720 Speaker 1: done poorly, it's incredibly distracting because it's so obvious that 32 00:02:05,760 --> 00:02:08,280 Speaker 1: the people or you know whatever that are in the 33 00:02:08,360 --> 00:02:11,760 Speaker 1: foreground of the shot aren't actually in whatever the environment is. 34 00:02:11,800 --> 00:02:16,200 Speaker 1: But that's the basic idea. It's to create a composite, 35 00:02:16,680 --> 00:02:21,359 Speaker 1: a combination of multiple shots into a single new shot, 36 00:02:22,000 --> 00:02:26,440 Speaker 1: so that the components from those two separate shots are 37 00:02:26,960 --> 00:02:29,320 Speaker 1: combined as if they're in the same place at the 38 00:02:29,360 --> 00:02:32,680 Speaker 1: same time. That's the basic idea. Now let's get to 39 00:02:32,760 --> 00:02:35,880 Speaker 1: the history, you know, the part that everyone really came 40 00:02:35,880 --> 00:02:39,600 Speaker 1: here for. But before we even get into the development 41 00:02:39,639 --> 00:02:42,000 Speaker 1: of it, we need to think about the early days 42 00:02:42,040 --> 00:02:45,760 Speaker 1: of film and talk about what film really is, because 43 00:02:45,800 --> 00:02:47,880 Speaker 1: that's going to help us understand the evolution of the 44 00:02:48,000 --> 00:02:52,119 Speaker 1: art form that made chroma key even a possibility. When 45 00:02:52,120 --> 00:02:56,079 Speaker 1: I say film in this case, I'm specifically referencing images 46 00:02:56,240 --> 00:02:59,720 Speaker 1: shot on a long strip of plastic upon which there 47 00:02:59,800 --> 00:03:03,640 Speaker 1: is a coding of light sensitive chemicals. Actually, there are 48 00:03:03,680 --> 00:03:07,640 Speaker 1: several layers of light sensitive particles in that thin strip 49 00:03:07,720 --> 00:03:10,280 Speaker 1: of film. You know, with modern film, you might be 50 00:03:10,320 --> 00:03:14,240 Speaker 1: talking about twenty or more layers on that thin little 51 00:03:14,240 --> 00:03:17,800 Speaker 1: piece of plastic. These layers include binding agents, you know, 52 00:03:18,040 --> 00:03:22,919 Speaker 1: essentially gelatin, and grains of silver halide crystals which react 53 00:03:22,960 --> 00:03:26,600 Speaker 1: to the light. These are those photosensitive chemicals, and also 54 00:03:26,680 --> 00:03:29,920 Speaker 1: some special molecules that bind with silver halide crystal so 55 00:03:29,960 --> 00:03:33,919 Speaker 1: that they transfer energy from specific wavelengths of light, which 56 00:03:34,240 --> 00:03:38,840 Speaker 1: we perceive as different colors. When light hits the silver 57 00:03:38,960 --> 00:03:43,360 Speaker 1: halide crystals coding this plastic, there is a chemical reaction, 58 00:03:43,600 --> 00:03:46,160 Speaker 1: and you can think of it as a chemical record 59 00:03:46,560 --> 00:03:50,360 Speaker 1: of that instant of time. Whatever light hit the film 60 00:03:50,440 --> 00:03:54,360 Speaker 1: is recorded there on this piece of plastics. So if 61 00:03:54,360 --> 00:03:57,800 Speaker 1: you position the lenses so that you can direct specific 62 00:03:57,960 --> 00:04:01,480 Speaker 1: light to that film, you can take a photograph. You 63 00:04:01,560 --> 00:04:04,640 Speaker 1: must use some form of shutter to block out the 64 00:04:04,760 --> 00:04:07,520 Speaker 1: light until you're ready to take your image. Then you 65 00:04:07,640 --> 00:04:11,160 Speaker 1: open the shutter. This exposes that piece of film to 66 00:04:11,240 --> 00:04:14,000 Speaker 1: the light that's being reflected off of whatever it is 67 00:04:14,040 --> 00:04:17,599 Speaker 1: your photographing. Remember when we see things, we're seeing light 68 00:04:17,800 --> 00:04:21,039 Speaker 1: bouncing off of that and the color of the stuff 69 00:04:21,080 --> 00:04:26,159 Speaker 1: we see is dependent upon which frequencies of light bounce 70 00:04:26,279 --> 00:04:30,120 Speaker 1: off of that thing. So then the shutter closes on 71 00:04:30,160 --> 00:04:33,000 Speaker 1: your camera and you've got your chemical record. And the 72 00:04:33,040 --> 00:04:36,600 Speaker 1: shutter is necessary because, as I said, these chemicals react 73 00:04:36,600 --> 00:04:39,240 Speaker 1: to light. If you just had this stuff exposed to 74 00:04:39,320 --> 00:04:42,320 Speaker 1: light all the time, it would have already reacted. You 75 00:04:42,320 --> 00:04:43,880 Speaker 1: would not be able to use it to take a 76 00:04:43,920 --> 00:04:46,839 Speaker 1: photograph of anything. If you want to learn more about 77 00:04:46,880 --> 00:04:51,000 Speaker 1: this process, which is fascinating, but really the process of 78 00:04:51,000 --> 00:04:53,240 Speaker 1: photography is far enough out of the scope of this 79 00:04:53,279 --> 00:04:56,200 Speaker 1: episode that I don't want to go into it much further. 80 00:04:56,680 --> 00:05:00,440 Speaker 1: I do recommend you go to how Stuff Works dot Calm. 81 00:05:00,480 --> 00:05:03,880 Speaker 1: That's my old employer. I don't technically work for How 82 00:05:03,920 --> 00:05:07,240 Speaker 1: Stuff Works anymore, but you can go to that website 83 00:05:07,360 --> 00:05:10,760 Speaker 1: and you look at the article how Photographic Film Works. 84 00:05:11,080 --> 00:05:13,760 Speaker 1: It was written by Chuck Woodworth and it's a great 85 00:05:13,880 --> 00:05:16,839 Speaker 1: example of the health Stuff Work style, and it goes 86 00:05:16,839 --> 00:05:20,720 Speaker 1: into the chemistry and physics of the photographic process, but 87 00:05:21,000 --> 00:05:23,279 Speaker 1: we'll skim over the rest of that for the purposes 88 00:05:23,320 --> 00:05:26,640 Speaker 1: of this episode. So, now the film on the camera 89 00:05:26,760 --> 00:05:30,159 Speaker 1: has a latent image on it, and it represents the 90 00:05:30,279 --> 00:05:33,880 Speaker 1: moment in time the shutter allowed light to pass from 91 00:05:33,920 --> 00:05:37,080 Speaker 1: the lens to hit the film. But in a film 92 00:05:37,200 --> 00:05:40,960 Speaker 1: camera a cinema camera, you're talking about a series of 93 00:05:41,080 --> 00:05:45,960 Speaker 1: latent images. Motors pull this strip of film at a 94 00:05:46,040 --> 00:05:50,000 Speaker 1: steady speed through the frame of the camera where the 95 00:05:50,000 --> 00:05:54,600 Speaker 1: shutter opens and closes at a regular uh frequency. And 96 00:05:54,640 --> 00:06:00,120 Speaker 1: the standard speed of capturing images is twenty four frames 97 00:06:00,200 --> 00:06:04,000 Speaker 1: per second, so a film camera is capturing twenty four 98 00:06:04,160 --> 00:06:08,480 Speaker 1: photographs every second. The latent images needs some processing in 99 00:06:08,560 --> 00:06:10,800 Speaker 1: order to create something that can be fed through a 100 00:06:10,839 --> 00:06:14,279 Speaker 1: film projector. The development process creates a negative image of 101 00:06:14,279 --> 00:06:18,240 Speaker 1: the chemical record, and that means that the darkest areas 102 00:06:18,279 --> 00:06:21,120 Speaker 1: of the image represent the spots where the film received 103 00:06:21,120 --> 00:06:24,919 Speaker 1: the most light. It's the opposite of what you would expect, 104 00:06:25,000 --> 00:06:28,080 Speaker 1: right Anything that would be dark in a photograph will 105 00:06:28,120 --> 00:06:31,359 Speaker 1: be light on a negative and vice versa. This negative 106 00:06:31,400 --> 00:06:33,599 Speaker 1: has to be transferred onto another roll of film to 107 00:06:33,600 --> 00:06:36,080 Speaker 1: create a positive image. In a process that I'm also 108 00:06:36,120 --> 00:06:37,719 Speaker 1: not going to cover because we need some time for 109 00:06:37,760 --> 00:06:41,159 Speaker 1: actual topic. Right. So, when we watch a film, we 110 00:06:41,279 --> 00:06:45,080 Speaker 1: have the perception that what we're viewing are moving objects 111 00:06:45,200 --> 00:06:48,640 Speaker 1: up on a screen, but that is an illusion. What 112 00:06:48,800 --> 00:06:52,040 Speaker 1: we're really seeing with true film is that it's a 113 00:06:52,080 --> 00:06:55,760 Speaker 1: series of photographs. The projector is playing those photographs at 114 00:06:55,800 --> 00:06:58,039 Speaker 1: the same speed that the film camera used to make 115 00:06:58,080 --> 00:07:02,680 Speaker 1: them twenty four frames per second usually. I mean, if 116 00:07:02,720 --> 00:07:04,960 Speaker 1: you wanted to play stuff in slow motion, then you 117 00:07:04,960 --> 00:07:07,120 Speaker 1: would shoot a film at a much higher frame rate, 118 00:07:07,160 --> 00:07:10,360 Speaker 1: like forty eight frames per second, but you would play 119 00:07:10,360 --> 00:07:13,560 Speaker 1: it back at the standard twenty four frames per second, 120 00:07:13,800 --> 00:07:17,760 Speaker 1: and that would give you the slow motion effect. And 121 00:07:17,800 --> 00:07:21,160 Speaker 1: back in the old days, cameras were hand cranked, so 122 00:07:21,680 --> 00:07:25,120 Speaker 1: you would get kind of twenty four frames per second, 123 00:07:25,600 --> 00:07:28,360 Speaker 1: but this would result in sort of that herky jerky 124 00:07:28,440 --> 00:07:33,880 Speaker 1: movement we associate with old movies that was hand cranked cinematography, 125 00:07:33,960 --> 00:07:38,040 Speaker 1: and sometimes people would turn the crank a little faster 126 00:07:38,160 --> 00:07:40,560 Speaker 1: or a little slower than others, so you don't really 127 00:07:40,560 --> 00:07:44,760 Speaker 1: have a consistent experience there, because the playback speed, especially 128 00:07:44,800 --> 00:07:47,760 Speaker 1: if you're playing it in a modern projector, is going 129 00:07:47,800 --> 00:07:51,400 Speaker 1: to be standard, even if the recording speed wasn't. But 130 00:07:51,520 --> 00:07:53,680 Speaker 1: never mind all that. If you were to stop the 131 00:07:53,720 --> 00:07:57,480 Speaker 1: projectors reels at any given moment in the playback of 132 00:07:57,520 --> 00:08:00,720 Speaker 1: a film, you would see a still m page. You 133 00:08:00,720 --> 00:08:03,320 Speaker 1: would advance the reel by one frame, and you would 134 00:08:03,320 --> 00:08:06,920 Speaker 1: see the next image in the next photograph in that series, 135 00:08:07,200 --> 00:08:09,240 Speaker 1: and you would likely be able to pick out how 136 00:08:09,280 --> 00:08:12,440 Speaker 1: things are slightly different from the first frame you looked 137 00:08:12,440 --> 00:08:15,160 Speaker 1: at and the next frame. And this is the same 138 00:08:15,200 --> 00:08:18,080 Speaker 1: principle that's behind animation. If you've ever taken a pad 139 00:08:18,120 --> 00:08:21,800 Speaker 1: of sticky notes and you drawn little figures on page 140 00:08:21,800 --> 00:08:23,680 Speaker 1: after page after page, so that when you flip the 141 00:08:23,720 --> 00:08:26,960 Speaker 1: pages you get a simple little cartoon, then you've engaged 142 00:08:27,000 --> 00:08:30,080 Speaker 1: in the same art form as great cinematographers. Then maybe 143 00:08:30,080 --> 00:08:32,280 Speaker 1: your work was even better than theirs. I'm not one 144 00:08:32,360 --> 00:08:34,520 Speaker 1: to judge. Now, why would I go to the trouble 145 00:08:34,600 --> 00:08:36,920 Speaker 1: to cover the basics of film, Well, it's because the 146 00:08:37,000 --> 00:08:40,800 Speaker 1: very nature of film inspired certain people to experiment with it, 147 00:08:40,840 --> 00:08:43,760 Speaker 1: to try stuff that would be impossible to replicate in 148 00:08:43,760 --> 00:08:46,440 Speaker 1: a real world setting, or at least it would be 149 00:08:46,960 --> 00:08:51,800 Speaker 1: really difficult. Film wasn't a substitution for theater in theater, 150 00:08:51,920 --> 00:08:55,199 Speaker 1: you can create a few interesting effects. Generally your options 151 00:08:55,200 --> 00:08:59,320 Speaker 1: are limited to things like lighting tricks. Maybe some creative 152 00:08:59,360 --> 00:09:03,040 Speaker 1: sets are called costumes, maybe an even a stage illusion 153 00:09:03,200 --> 00:09:06,359 Speaker 1: or two, and perhaps some sound design. But with film 154 00:09:06,400 --> 00:09:10,079 Speaker 1: there were other possibilities, and one fellow who recognized those 155 00:09:10,120 --> 00:09:16,319 Speaker 1: possibilities was the French filmmaker and illusionist George Meillier. He 156 00:09:16,360 --> 00:09:19,960 Speaker 1: was born in Paris. You know Paris in eighteen sixty one. 157 00:09:20,400 --> 00:09:23,000 Speaker 1: Let that sink in for a moment. This man was 158 00:09:23,200 --> 00:09:26,400 Speaker 1: born while the Civil War was going on in the 159 00:09:26,480 --> 00:09:30,960 Speaker 1: United States. He became interested in stagecraft and magic, and 160 00:09:31,000 --> 00:09:34,440 Speaker 1: by the eighteen nineties he was a successful stage magician. 161 00:09:34,960 --> 00:09:38,480 Speaker 1: In eight he saw an early film exhibition made by 162 00:09:38,480 --> 00:09:42,760 Speaker 1: the Lumier Brothers and he became entranced by this new medium. 163 00:09:42,840 --> 00:09:45,960 Speaker 1: His experience and illusions encouraged him to find ways to 164 00:09:46,040 --> 00:09:49,880 Speaker 1: experiment with film to achieve new effects, stuff that wouldn't 165 00:09:49,920 --> 00:09:52,959 Speaker 1: be possible to do in the real world. He was 166 00:09:53,000 --> 00:09:56,400 Speaker 1: a special effects and film pioneer. He established methods to 167 00:09:56,440 --> 00:10:01,560 Speaker 1: shoot slow motion, stop motion animation, to dissolves, and tricks 168 00:10:01,600 --> 00:10:07,240 Speaker 1: like super imposition and double exposure around. Maillier had a 169 00:10:07,280 --> 00:10:10,200 Speaker 1: really cool idea. He wanted to create a truly bizarre 170 00:10:10,240 --> 00:10:13,160 Speaker 1: special effect in which an actor would appear to remove 171 00:10:13,280 --> 00:10:18,760 Speaker 1: his own head on screen. But how would he accomplish this, Well, 172 00:10:18,800 --> 00:10:22,480 Speaker 1: the secret was in shooting multiple exposures of the same 173 00:10:22,600 --> 00:10:26,120 Speaker 1: reel of film. Typically, after you expose film to light, 174 00:10:26,200 --> 00:10:28,959 Speaker 1: you want to avoid doing that again because you will 175 00:10:29,000 --> 00:10:31,480 Speaker 1: interfere with that chemical record. You know, if you were 176 00:10:31,480 --> 00:10:34,800 Speaker 1: to ever take photographs with a film camera and then 177 00:10:34,920 --> 00:10:37,640 Speaker 1: someone were to open up the back of the camera 178 00:10:37,640 --> 00:10:43,000 Speaker 1: and expose the film to regular light, you could potentially 179 00:10:43,080 --> 00:10:45,680 Speaker 1: ruin shots that were already made, plus ruin the film 180 00:10:45,720 --> 00:10:48,760 Speaker 1: for the next couple of shots. It's not something that 181 00:10:48,840 --> 00:10:52,160 Speaker 1: you typically want to do. More light will cause further 182 00:10:52,240 --> 00:10:56,520 Speaker 1: reactions chemical reactions on the actual plastic film, and your 183 00:10:56,520 --> 00:10:59,800 Speaker 1: shot gets ruined. If you've ever used the cameras that 184 00:11:00,240 --> 00:11:02,800 Speaker 1: quite line up the film properly at the very beginning 185 00:11:02,800 --> 00:11:04,760 Speaker 1: of the very end, you might even notice that a 186 00:11:04,800 --> 00:11:09,160 Speaker 1: couple of photos on those sections of the film role 187 00:11:09,640 --> 00:11:13,240 Speaker 1: have two sets of images superimposed on top of one another, 188 00:11:14,000 --> 00:11:17,200 Speaker 1: and that's because that little section of film was exposed 189 00:11:17,240 --> 00:11:21,679 Speaker 1: more than once. Mellier did this on purpose. He would 190 00:11:21,720 --> 00:11:24,360 Speaker 1: set up a shot and he would use a lens 191 00:11:24,440 --> 00:11:27,559 Speaker 1: that had some of the lens blacked out so that 192 00:11:27,640 --> 00:11:30,360 Speaker 1: light could not pass through that part of the lens. 193 00:11:30,760 --> 00:11:33,840 Speaker 1: And we refer to this as a MAT M A 194 00:11:34,120 --> 00:11:36,240 Speaker 1: T T E. And you can think of it like 195 00:11:36,280 --> 00:11:39,200 Speaker 1: a mask for the lens, and that would mean a 196 00:11:39,240 --> 00:11:41,839 Speaker 1: section of each frame corresponding to that part of the 197 00:11:41,880 --> 00:11:44,719 Speaker 1: mat would remain unexposed to light. He would shoot the 198 00:11:44,880 --> 00:11:49,120 Speaker 1: scene as rehearsed. Afterward, he would rewind the exposed film 199 00:11:49,160 --> 00:11:51,200 Speaker 1: in the camera, beat it right back in as if 200 00:11:51,200 --> 00:11:53,640 Speaker 1: he was going to shoot something all for the first time. 201 00:11:54,480 --> 00:11:58,360 Speaker 1: And he would then replace this mat with a new one, 202 00:11:58,880 --> 00:12:02,119 Speaker 1: and the new man at would block out everything except 203 00:12:02,840 --> 00:12:07,199 Speaker 1: the section that previously was unexposed, So, in other words, 204 00:12:07,400 --> 00:12:10,160 Speaker 1: the part that was black would now be clear and 205 00:12:10,200 --> 00:12:13,960 Speaker 1: the rest of the lens that was previously unblacked would 206 00:12:14,000 --> 00:12:16,920 Speaker 1: be blacked. So you replace one mat with a different one, 207 00:12:17,640 --> 00:12:20,400 Speaker 1: so he would then be able to film something totally 208 00:12:20,400 --> 00:12:22,720 Speaker 1: new into this same role of film, and this time 209 00:12:22,800 --> 00:12:25,480 Speaker 1: the camera would pick up a new scene, and by 210 00:12:25,559 --> 00:12:27,760 Speaker 1: changing things between one section and the other, he could 211 00:12:27,800 --> 00:12:31,120 Speaker 1: create weird effects like the head removal trick. It would 212 00:12:31,120 --> 00:12:33,680 Speaker 1: appear as though all of this was shot at the 213 00:12:33,720 --> 00:12:36,600 Speaker 1: same time on the same role of film, but in fact, 214 00:12:37,000 --> 00:12:39,800 Speaker 1: through careful control of where the light would go, Millier 215 00:12:39,960 --> 00:12:44,440 Speaker 1: would use the same film twice or more to produce 216 00:12:44,480 --> 00:12:46,880 Speaker 1: cool results. And if you want to see an example 217 00:12:46,920 --> 00:12:50,000 Speaker 1: of what I'm talking about, and I highly recommend you 218 00:12:50,080 --> 00:12:53,440 Speaker 1: check this out because it is amazing even today, go 219 00:12:53,600 --> 00:12:56,440 Speaker 1: to YouTube and do a search for the short film 220 00:12:56,920 --> 00:13:01,000 Speaker 1: four Heads are better than One. The activity of this film, 221 00:13:01,000 --> 00:13:04,560 Speaker 1: which by the way, lasts less than a minute, is 222 00:13:04,600 --> 00:13:09,920 Speaker 1: still astonishing. To say his experimental work was influential would 223 00:13:09,960 --> 00:13:13,520 Speaker 1: be a gross understatement. Other filmmakers inspired by the work 224 00:13:13,520 --> 00:13:17,599 Speaker 1: of Mailier tried new techniques that built upon the foundation 225 00:13:17,640 --> 00:13:22,360 Speaker 1: he established. For example, filmmaker and documentary and Norman Down 226 00:13:22,600 --> 00:13:26,680 Speaker 1: wanted to shoot films at historic buildings around California, but 227 00:13:27,200 --> 00:13:31,240 Speaker 1: several of those buildings had been damaged or even partly destroyed. 228 00:13:31,840 --> 00:13:35,920 Speaker 1: Other historic buildings had modern stuff like light poles in 229 00:13:35,960 --> 00:13:37,920 Speaker 1: front of them. He didn't want that to be in 230 00:13:37,920 --> 00:13:40,600 Speaker 1: the shot, so he wanted to show the buildings as 231 00:13:40,640 --> 00:13:44,480 Speaker 1: they had appeared in their original form before the decay, 232 00:13:44,679 --> 00:13:49,560 Speaker 1: before modern technology had advanced into the area. So he 233 00:13:49,679 --> 00:13:53,719 Speaker 1: came up with a really clever idea. Dawn placed a 234 00:13:53,800 --> 00:13:57,200 Speaker 1: pain of glass between the camera and the scene he 235 00:13:57,280 --> 00:14:00,640 Speaker 1: wanted to shoot, and on that pain of ass he 236 00:14:00,720 --> 00:14:04,600 Speaker 1: had paintings to enhance the scene. If a building's roof 237 00:14:04,640 --> 00:14:06,880 Speaker 1: had caved in, he would frame up the shot and 238 00:14:06,880 --> 00:14:09,440 Speaker 1: then have an artist paint a roof on the glass 239 00:14:09,600 --> 00:14:12,600 Speaker 1: so that when viewed through the camera, the painting and 240 00:14:12,640 --> 00:14:15,600 Speaker 1: the building behind it would line up and the building 241 00:14:15,600 --> 00:14:18,160 Speaker 1: would appear to be whole again. Or he might want 242 00:14:18,160 --> 00:14:20,880 Speaker 1: to cover up stuff like those telephone poles, he would 243 00:14:20,880 --> 00:14:24,040 Speaker 1: have an artist paint trees on the glass so from 244 00:14:24,040 --> 00:14:27,880 Speaker 1: the camera's perspective the polls were hidden. His process also 245 00:14:27,920 --> 00:14:32,479 Speaker 1: involved double exposures. This was an example of a Matt painting, 246 00:14:32,880 --> 00:14:35,840 Speaker 1: and he would claim credit for inventing this, and he 247 00:14:35,880 --> 00:14:39,080 Speaker 1: even applied for a patent on it, but subsequent lawsuits 248 00:14:39,160 --> 00:14:42,640 Speaker 1: established other filmmakers were using similar approaches, and the patent 249 00:14:42,640 --> 00:14:46,600 Speaker 1: office ultimately denied the claim, but Matt paintings would become 250 00:14:46,600 --> 00:14:50,160 Speaker 1: an important part of filmmaking from that point forward. One 251 00:14:50,240 --> 00:14:54,200 Speaker 1: disadvantage to these early film effects was they required the 252 00:14:54,280 --> 00:14:57,560 Speaker 1: camera to remain stationary that the whole process. You couldn't 253 00:14:57,680 --> 00:15:01,000 Speaker 1: move the camera at all or else your shots wouldn't 254 00:15:01,040 --> 00:15:03,560 Speaker 1: line up, so you wanted the camera to remain in 255 00:15:03,600 --> 00:15:07,320 Speaker 1: one place through all of these different exposures. Another problem 256 00:15:07,400 --> 00:15:10,400 Speaker 1: was that no action could cross the Matt line because 257 00:15:10,400 --> 00:15:13,480 Speaker 1: it would get cut off as it moved beyond that 258 00:15:13,880 --> 00:15:18,120 Speaker 1: invisible at least from the audience's perspective line. Now, let's 259 00:15:18,160 --> 00:15:20,920 Speaker 1: move on up to nine eighteen, when a guy named 260 00:15:20,960 --> 00:15:26,880 Speaker 1: Frank Williams created the Williams process, which honestly seems pretty 261 00:15:26,920 --> 00:15:31,160 Speaker 1: convenient to me. The Williams process allowed for more movement 262 00:15:31,400 --> 00:15:34,720 Speaker 1: and involved shooting actors against a solid background, such as 263 00:15:34,760 --> 00:15:39,800 Speaker 1: a black or blue curtain on very high contrast film. 264 00:15:39,840 --> 00:15:44,520 Speaker 1: The process sometimes required multiple transfers onto new film until 265 00:15:44,560 --> 00:15:48,840 Speaker 1: you arrived at a black silhouette against a pure white background, 266 00:15:49,000 --> 00:15:51,520 Speaker 1: the negative image of what you were shooting before, and 267 00:15:51,560 --> 00:15:54,280 Speaker 1: this was called a holdout matt. The way these transfers 268 00:15:54,280 --> 00:15:56,640 Speaker 1: typically would work is that you would put one strip 269 00:15:56,840 --> 00:16:00,760 Speaker 1: of shot developed film into a camera, so you've already 270 00:16:00,760 --> 00:16:02,640 Speaker 1: shot on it, but you're putting it through the camera again, 271 00:16:03,520 --> 00:16:08,040 Speaker 1: and you would put a second strip of film that 272 00:16:08,200 --> 00:16:12,320 Speaker 1: is unshot, it's unprocessed, no no lights hit it, and 273 00:16:12,400 --> 00:16:16,480 Speaker 1: put it right up against the first developed piece of film, 274 00:16:16,720 --> 00:16:19,760 Speaker 1: you would shine light through the camera and you would 275 00:16:19,800 --> 00:16:23,280 Speaker 1: let it just run, and this way you would transfer 276 00:16:23,400 --> 00:16:27,760 Speaker 1: the images from one strip to the other. And this 277 00:16:27,880 --> 00:16:30,960 Speaker 1: was called by packing because you were putting two different 278 00:16:31,000 --> 00:16:35,479 Speaker 1: pieces of film through the camera to achieve this process. 279 00:16:35,520 --> 00:16:38,360 Speaker 1: And you could also do this not just with developed 280 00:16:38,360 --> 00:16:40,880 Speaker 1: film where you're making copies. You could do it with negatives. 281 00:16:40,920 --> 00:16:44,400 Speaker 1: You could do it in a way to increase contrast 282 00:16:44,520 --> 00:16:47,240 Speaker 1: from copy to copy, until you were able to create 283 00:16:47,640 --> 00:16:51,760 Speaker 1: a holdout matt. Reverse printing the holdout Matt creates a 284 00:16:51,840 --> 00:16:56,040 Speaker 1: white silhouette on a black background or a cover mat. 285 00:16:56,120 --> 00:16:58,400 Speaker 1: So now you've got to hold out Matt and a 286 00:16:58,440 --> 00:17:01,360 Speaker 1: cover matt. You would take the footage of a previously 287 00:17:01,400 --> 00:17:04,520 Speaker 1: shot background. Let's say it's a foreboding forest. So you've 288 00:17:04,520 --> 00:17:07,240 Speaker 1: shot your actors in a sound stage, but you want 289 00:17:07,240 --> 00:17:10,280 Speaker 1: the background to be this really scary looking forest, and 290 00:17:10,400 --> 00:17:13,040 Speaker 1: you would bypack a film and camera with the background 291 00:17:13,119 --> 00:17:17,160 Speaker 1: footage that you had shot and the black silhouette holdout 292 00:17:17,320 --> 00:17:21,800 Speaker 1: Matt of the actor's footage that you shot. Then you 293 00:17:21,840 --> 00:17:26,400 Speaker 1: would transfer this combination to a third piece of unexposed 294 00:17:26,440 --> 00:17:29,240 Speaker 1: film by again shining a light through those other two 295 00:17:29,240 --> 00:17:33,479 Speaker 1: pieces and because the background on the holdout mat is white, 296 00:17:34,480 --> 00:17:36,840 Speaker 1: the light passes through it easily and it hits the 297 00:17:36,920 --> 00:17:40,520 Speaker 1: previously shot background image that comes through and gets copied 298 00:17:40,520 --> 00:17:44,520 Speaker 1: onto the blank film. The silhouette of your actors is 299 00:17:44,560 --> 00:17:49,080 Speaker 1: black that prevents light from passing through. So the previously 300 00:17:49,160 --> 00:17:52,440 Speaker 1: blank third piece of film now has a background image 301 00:17:52,520 --> 00:17:55,800 Speaker 1: and this dark silhouette of actors moving through the frame. 302 00:17:56,760 --> 00:17:59,600 Speaker 1: Then you would have to take that piece of film 303 00:17:59,640 --> 00:18:02,240 Speaker 1: that has this black silhouette and you have to bypack 304 00:18:02,280 --> 00:18:05,199 Speaker 1: it with the original footage of the actor, not the silhouette, 305 00:18:05,200 --> 00:18:08,760 Speaker 1: but the actual actor footage. And now the real actor 306 00:18:09,000 --> 00:18:11,600 Speaker 1: is on top of the silhouette and appears to actually 307 00:18:11,640 --> 00:18:14,359 Speaker 1: be in front of whatever the background images, in our case, 308 00:18:14,400 --> 00:18:18,360 Speaker 1: the foreboding forest. Because this type of matt moves from 309 00:18:18,440 --> 00:18:22,120 Speaker 1: frame to frame, it's called a traveling matt. And if 310 00:18:22,160 --> 00:18:25,840 Speaker 1: you remember Fraggle Rock, you might remember traveling matt is 311 00:18:25,880 --> 00:18:29,399 Speaker 1: the name of go Bo's uncle. Gobo, by the way, 312 00:18:29,640 --> 00:18:32,320 Speaker 1: is another stage in lighting term. It stands for a 313 00:18:32,359 --> 00:18:35,320 Speaker 1: template or stencil that controls the shape of a lamps 314 00:18:35,359 --> 00:18:41,240 Speaker 1: emitted light. So some of the Fraggles had fun industry 315 00:18:41,359 --> 00:18:44,879 Speaker 1: names Gobo and traveling Matt. When we come back, we 316 00:18:44,960 --> 00:18:49,280 Speaker 1: will continue down the history of how chroma key came about, 317 00:18:49,359 --> 00:18:59,160 Speaker 1: but first let's take a quick break. Before the break, 318 00:18:59,240 --> 00:19:02,800 Speaker 1: I was talking up the Williams process, but see Dodge 319 00:19:02,880 --> 00:19:06,800 Speaker 1: Dunning would improve upon the Williams process by using yellow 320 00:19:06,840 --> 00:19:09,200 Speaker 1: light to shoot the actor in front of a blue screen, 321 00:19:09,800 --> 00:19:13,760 Speaker 1: creating the Dunning process. And this was used extensively in 322 00:19:13,800 --> 00:19:17,359 Speaker 1: the classic nineteen thirty three film King Kong, and they 323 00:19:17,359 --> 00:19:19,639 Speaker 1: weren't great for black and white film. Remember this is 324 00:19:19,680 --> 00:19:23,640 Speaker 1: before anyone was shooting on color. So although I mean 325 00:19:23,640 --> 00:19:26,600 Speaker 1: there were ways of treating film to create color, but 326 00:19:26,720 --> 00:19:29,440 Speaker 1: this was standard black and white film, so he didn't 327 00:19:29,440 --> 00:19:32,560 Speaker 1: have to worry about the weird lighting. But if you 328 00:19:32,560 --> 00:19:35,760 Speaker 1: wanted to shoot in color, that was gonna cause require 329 00:19:35,840 --> 00:19:41,080 Speaker 1: other considerations. Around the same time, engineers were developing the 330 00:19:41,160 --> 00:19:45,360 Speaker 1: optical printer, which really simplified the process of transferring images 331 00:19:45,400 --> 00:19:47,720 Speaker 1: from one strip of film to another. And I had 332 00:19:47,720 --> 00:19:52,639 Speaker 1: talked about by packing, but the optical process could be 333 00:19:53,080 --> 00:19:56,399 Speaker 1: an alternative to that. It didn't eliminate it, but it 334 00:19:56,480 --> 00:19:59,240 Speaker 1: was a different way to achieve the same thing. Essentially, 335 00:20:00,000 --> 00:20:03,720 Speaker 1: an optical printer has a projector on one side and 336 00:20:03,760 --> 00:20:06,840 Speaker 1: a camera. On the other the projector shoots at the 337 00:20:06,880 --> 00:20:10,160 Speaker 1: projected image that then gets copied onto a new unexposed 338 00:20:10,240 --> 00:20:12,639 Speaker 1: role of film inside the camera. And it also allowed 339 00:20:12,640 --> 00:20:15,680 Speaker 1: filmmakers to create new effects by changing the focal point 340 00:20:15,920 --> 00:20:18,639 Speaker 1: of the camera or the distance between the projector and 341 00:20:18,680 --> 00:20:21,840 Speaker 1: the camera, and rather than bypacking camera, you just use 342 00:20:21,920 --> 00:20:25,440 Speaker 1: this process you could get better results. The first mass 343 00:20:25,480 --> 00:20:28,200 Speaker 1: produced optical printer hit the market in the mid nineteen 344 00:20:28,280 --> 00:20:32,240 Speaker 1: forties came from a company called Acme Done. In addition, 345 00:20:32,359 --> 00:20:37,200 Speaker 1: filmmakers created rear projection background so in these actors would 346 00:20:37,240 --> 00:20:41,040 Speaker 1: perform in front of a screen like a projection screen, 347 00:20:41,240 --> 00:20:44,800 Speaker 1: not a green screen or a blue screen, and behind 348 00:20:45,160 --> 00:20:48,400 Speaker 1: that screen would be a film projector and it would 349 00:20:48,400 --> 00:20:52,879 Speaker 1: provide a projected background image. You could do this in 350 00:20:52,960 --> 00:20:56,359 Speaker 1: place of the processes have already described, putting your actors 351 00:20:56,400 --> 00:20:58,679 Speaker 1: in front of a screen that shows whatever background you 352 00:20:58,720 --> 00:21:01,560 Speaker 1: wanted in the background could be fairly static, but didn't 353 00:21:01,640 --> 00:21:04,679 Speaker 1: have to be. You could include a background that was 354 00:21:05,000 --> 00:21:08,359 Speaker 1: actually dynamic, showing movement. It could be a film in 355 00:21:08,440 --> 00:21:11,320 Speaker 1: of itself. This was used a lot in shots where 356 00:21:11,320 --> 00:21:14,639 Speaker 1: people were in vehicles and talking with one another, so 357 00:21:14,760 --> 00:21:17,720 Speaker 1: rather than setting up a car on a trailer and 358 00:21:17,800 --> 00:21:19,679 Speaker 1: shooting it in the real world with the camera on 359 00:21:19,720 --> 00:21:21,800 Speaker 1: the trailer, or or worse yet, trying to figure out 360 00:21:21,840 --> 00:21:24,760 Speaker 1: how to fit a camera onto a real moving car 361 00:21:24,920 --> 00:21:28,160 Speaker 1: that's operated by an actor. You would typically have performance 362 00:21:28,200 --> 00:21:31,800 Speaker 1: sitting in a stationary vehicle, and the screen behind and 363 00:21:31,880 --> 00:21:35,760 Speaker 1: sometimes to either side of them would display previously shot 364 00:21:35,760 --> 00:21:40,080 Speaker 1: footage of scenery going by from the correct perspective, as 365 00:21:40,119 --> 00:21:42,920 Speaker 1: if the car were driving down the road. This wasn't 366 00:21:42,960 --> 00:21:46,399 Speaker 1: necessarily convincing, mind you, but it was an interesting technique. 367 00:21:46,840 --> 00:21:50,639 Speaker 1: In ninety two, engineers created a process to produce films 368 00:21:50,640 --> 00:21:56,400 Speaker 1: and color called appropriately Technicolor. Interestingly, in this process, images 369 00:21:56,480 --> 00:22:00,359 Speaker 1: would be captured to three strips of black and white film. 370 00:22:00,560 --> 00:22:04,000 Speaker 1: At this stage is the try strip approach. This was 371 00:22:04,040 --> 00:22:07,840 Speaker 1: not the original version of Technicolor. It was technically the 372 00:22:07,880 --> 00:22:11,640 Speaker 1: fourth incarnation of the Technicolor technology, but it's the important 373 00:22:11,640 --> 00:22:15,480 Speaker 1: one for our discussion. So how do you produce a 374 00:22:15,560 --> 00:22:19,200 Speaker 1: color image if you're using black and white film as 375 00:22:19,240 --> 00:22:22,560 Speaker 1: your medium, Well, first you have to shoot your footage 376 00:22:22,640 --> 00:22:27,640 Speaker 1: and inside an early technic color tri strip camera. Behind 377 00:22:28,119 --> 00:22:31,760 Speaker 1: the lens was an optical cube and it acted as 378 00:22:31,760 --> 00:22:36,760 Speaker 1: a prism prisms break up incoming light into bands of frequencies, 379 00:22:37,160 --> 00:22:40,639 Speaker 1: and you've likely had one, or played with one, or 380 00:22:40,640 --> 00:22:42,879 Speaker 1: at least seen one. That's the kind of stuff, you know. 381 00:22:42,920 --> 00:22:44,800 Speaker 1: The light goes through it and then it makes rainbows. 382 00:22:44,800 --> 00:22:48,760 Speaker 1: You see a little rainbow pattern projected somewhere. This prism 383 00:22:48,960 --> 00:22:51,919 Speaker 1: would break up the incoming light into three general bands 384 00:22:51,960 --> 00:22:56,040 Speaker 1: that corresponded with red, green, and blue. Each of those 385 00:22:56,080 --> 00:22:59,440 Speaker 1: bands of light would hit one of three strips of 386 00:22:59,480 --> 00:23:02,639 Speaker 1: black and white film inside the camera, So one strip 387 00:23:02,680 --> 00:23:04,840 Speaker 1: of film would be exposed to all the red light 388 00:23:05,000 --> 00:23:07,840 Speaker 1: coming from a scene, one from all the green light 389 00:23:08,000 --> 00:23:10,960 Speaker 1: coming from a scene, one from the blue. The concentration 390 00:23:10,960 --> 00:23:13,360 Speaker 1: of each color in the scene would affect how much 391 00:23:13,440 --> 00:23:16,199 Speaker 1: light was hitting each strip of film, so you'd end 392 00:23:16,280 --> 00:23:19,840 Speaker 1: up with three negatives of your scene that we're all 393 00:23:20,160 --> 00:23:23,800 Speaker 1: perfectly synchronized, all of them in black and white, but 394 00:23:24,200 --> 00:23:28,439 Speaker 1: each with different levels of brightness for different objects. It 395 00:23:28,480 --> 00:23:31,520 Speaker 1: all depended on what color the objects were in the scene. 396 00:23:31,800 --> 00:23:34,920 Speaker 1: A red chair, for example, would appear as a very 397 00:23:34,960 --> 00:23:37,560 Speaker 1: prominent image on the black and white film that was 398 00:23:37,640 --> 00:23:40,640 Speaker 1: hit with the red light, while it would be less 399 00:23:40,680 --> 00:23:45,120 Speaker 1: noticeable in the green and blue strips. Now you would 400 00:23:45,160 --> 00:23:48,240 Speaker 1: develop the negatives, and you would process the film, the 401 00:23:48,359 --> 00:23:51,320 Speaker 1: three strips of film, and you would print them just 402 00:23:51,359 --> 00:23:53,280 Speaker 1: as you would a regular black and white movie, and 403 00:23:53,320 --> 00:23:56,960 Speaker 1: you would technically have three identical black and white sequences 404 00:23:57,640 --> 00:24:01,080 Speaker 1: that only well, not identical, because the brightness would be 405 00:24:01,080 --> 00:24:03,400 Speaker 1: different between each, but they would be of the exact 406 00:24:03,440 --> 00:24:08,320 Speaker 1: same shot. You would then process these film strips by 407 00:24:08,440 --> 00:24:11,679 Speaker 1: dying each of them in their respective color, so you 408 00:24:11,680 --> 00:24:15,840 Speaker 1: would literally end up with a red tinted strip of film, 409 00:24:16,000 --> 00:24:19,320 Speaker 1: blue tinted strip of film, and a green tinted strip 410 00:24:19,440 --> 00:24:23,040 Speaker 1: of film. Then you would take these three dyed strips 411 00:24:23,080 --> 00:24:25,639 Speaker 1: of film and you would laminate them together, and you 412 00:24:25,680 --> 00:24:28,000 Speaker 1: would print that to a new role of film, and 413 00:24:28,080 --> 00:24:33,280 Speaker 1: you would have a color motion picture which was fairly accurate, 414 00:24:33,640 --> 00:24:36,680 Speaker 1: although the technical process would evolve over time to become 415 00:24:36,680 --> 00:24:39,720 Speaker 1: even more so. And the technicolor process is really what 416 00:24:39,840 --> 00:24:42,480 Speaker 1: set the stage for the next part of our story. 417 00:24:42,520 --> 00:24:45,119 Speaker 1: It's why I felt the need to even explain how 418 00:24:45,160 --> 00:24:47,760 Speaker 1: it worked. Now we get to a guy named Lawrence 419 00:24:48,160 --> 00:24:51,159 Speaker 1: Larry Butler. He was born in nineteen o eight and 420 00:24:51,200 --> 00:24:55,399 Speaker 1: he was actually a second generation optical effects professional. His father, 421 00:24:55,640 --> 00:24:59,440 Speaker 1: William Butler, had been a silent film actor who frequently 422 00:24:59,520 --> 00:25:03,879 Speaker 1: appeared indeed w Griffith Films. Larry worked on several motion 423 00:25:03,920 --> 00:25:07,280 Speaker 1: pictures in the nineteen thirties before creating a new compositing 424 00:25:07,320 --> 00:25:12,320 Speaker 1: process in for the film The Thief of Baghdad. In 425 00:25:12,359 --> 00:25:16,080 Speaker 1: that film, Butler introduced a new special effect approach, and 426 00:25:16,119 --> 00:25:19,280 Speaker 1: this would be the birth of the blue screen. All right, 427 00:25:19,320 --> 00:25:23,440 Speaker 1: So let's break down this process. It builds on Technicolor, 428 00:25:23,640 --> 00:25:26,760 Speaker 1: as I mentioned. So with Technicolor, you get three prints 429 00:25:26,760 --> 00:25:29,520 Speaker 1: of your shot right, one for red, one for green, 430 00:25:29,640 --> 00:25:32,960 Speaker 1: one for blue. If you created a solid backdrop in 431 00:25:33,080 --> 00:25:36,200 Speaker 1: one of those three colors and shot something in front 432 00:25:36,240 --> 00:25:39,560 Speaker 1: of that background, you could use that particular strip of 433 00:25:39,640 --> 00:25:44,040 Speaker 1: film to create a traveling matt. Remember, the color would 434 00:25:44,080 --> 00:25:47,040 Speaker 1: show up as very bright in your black and white 435 00:25:47,080 --> 00:25:49,920 Speaker 1: film print because a lot of light is reflecting off 436 00:25:50,040 --> 00:25:54,480 Speaker 1: of that particular color. Effectively, you could make a negative 437 00:25:54,600 --> 00:25:59,320 Speaker 1: image of whatever the foreground was. The stuff you're shooting 438 00:25:59,640 --> 00:26:03,080 Speaker 1: would be dark and the background would be bright. You 439 00:26:03,119 --> 00:26:05,359 Speaker 1: would have to make sure that nothing in the scene 440 00:26:05,480 --> 00:26:08,680 Speaker 1: had the same color, however, or else You're traveling matt 441 00:26:08,680 --> 00:26:11,480 Speaker 1: would effectively have holes in it because the color of 442 00:26:11,480 --> 00:26:14,720 Speaker 1: the foreground would match the color of the background. You've 443 00:26:14,720 --> 00:26:17,680 Speaker 1: probably seen this, if someone's ever worn a shirt that's 444 00:26:17,720 --> 00:26:20,280 Speaker 1: the same color as whatever screen they're supposed to be 445 00:26:20,320 --> 00:26:22,680 Speaker 1: standing in front of. The same thing would even happen 446 00:26:22,680 --> 00:26:26,720 Speaker 1: in film. It's just that it would happen well in 447 00:26:26,840 --> 00:26:29,399 Speaker 1: advance of anyone being able to see it happen, like 448 00:26:29,480 --> 00:26:31,040 Speaker 1: see the effect of it. Because you had to do 449 00:26:31,080 --> 00:26:33,800 Speaker 1: all this other processing. The other two strips of black 450 00:26:33,840 --> 00:26:37,040 Speaker 1: and white film would have pretty dark backgrounds because the 451 00:26:37,160 --> 00:26:40,360 Speaker 1: light projected onto them wouldn't match the color of the backdrop, 452 00:26:40,440 --> 00:26:43,879 Speaker 1: right uh. And you could take the film of a 453 00:26:43,920 --> 00:26:46,680 Speaker 1: background shot. This is called the background plate, So this 454 00:26:46,720 --> 00:26:50,240 Speaker 1: is previously shot film of whatever it is, whatever setting 455 00:26:50,440 --> 00:26:53,080 Speaker 1: you're planning on putting this stuff, and then you use 456 00:26:53,160 --> 00:26:56,520 Speaker 1: the traveling matt against it in an optical printer, and 457 00:26:56,560 --> 00:27:00,720 Speaker 1: that would produce a silhouette of the foreground action. And 458 00:27:00,800 --> 00:27:03,359 Speaker 1: it's that black hole that's the shape of whatever it 459 00:27:03,440 --> 00:27:05,960 Speaker 1: was you were shooting. You would take this new print 460 00:27:06,200 --> 00:27:08,200 Speaker 1: in which you've got the silhouette of your actually it's 461 00:27:08,280 --> 00:27:11,639 Speaker 1: the previously filmed backdrop, and combined that with the processed 462 00:27:11,680 --> 00:27:14,480 Speaker 1: color film to fill in that hole left by the 463 00:27:14,600 --> 00:27:18,440 Speaker 1: traveling Matt. So you've got this possibility now of creating 464 00:27:18,480 --> 00:27:21,880 Speaker 1: a traveling mat by taking advantage of the technicolor process. 465 00:27:21,920 --> 00:27:23,840 Speaker 1: But then you have to make a decision which of 466 00:27:23,920 --> 00:27:27,679 Speaker 1: the three colors should be the focus. Whichever color you 467 00:27:27,760 --> 00:27:31,080 Speaker 1: choose is going to determine what you can shoot, because 468 00:27:31,359 --> 00:27:33,800 Speaker 1: you can't have any objects or people in the scene 469 00:27:34,000 --> 00:27:37,360 Speaker 1: that have that color on them, or the traveling mat 470 00:27:37,480 --> 00:27:41,480 Speaker 1: won't work properly. This is what I mean when I say, 471 00:27:41,520 --> 00:27:44,080 Speaker 1: if you've ever seen someone on screen news had a 472 00:27:44,119 --> 00:27:47,439 Speaker 1: background effect bleed onto them because the color of clothing 473 00:27:47,480 --> 00:27:51,359 Speaker 1: they're wearing, what was letting it happen? You've seen that issue. 474 00:27:51,800 --> 00:27:55,359 Speaker 1: So Butler decided to go with blue as the backdrop color, 475 00:27:55,600 --> 00:27:58,440 Speaker 1: largely because he determined it was a color far removed 476 00:27:58,520 --> 00:28:01,679 Speaker 1: from skin tones, and he wanted to make sure that 477 00:28:01,720 --> 00:28:04,560 Speaker 1: actors wouldn't match the color of the background and mess 478 00:28:04,600 --> 00:28:07,200 Speaker 1: everything up. So as long as you weren't shooting anything 479 00:28:07,200 --> 00:28:09,760 Speaker 1: blue in the foreground, you could use this process to 480 00:28:09,760 --> 00:28:13,639 Speaker 1: make a composite image of the foreground action against a 481 00:28:13,760 --> 00:28:17,400 Speaker 1: different background. He also would combine the blue negative image 482 00:28:17,520 --> 00:28:21,080 Speaker 1: with the green positive or processed image to create a 483 00:28:21,119 --> 00:28:24,720 Speaker 1: better traveling Matt something a more solid silhouette. In other words, 484 00:28:25,160 --> 00:28:28,600 Speaker 1: Butler's contribution led to him winning an Academy Award for 485 00:28:28,640 --> 00:28:33,840 Speaker 1: this process. Still, this was an incredibly time consuming approach. 486 00:28:34,359 --> 00:28:37,159 Speaker 1: I'm sure you've gathered that just from my explanation of it. 487 00:28:37,520 --> 00:28:39,720 Speaker 1: Because you had to shoot your sequence, you had to 488 00:28:39,760 --> 00:28:42,800 Speaker 1: create the traveling matt negative, you had to combine that 489 00:28:42,920 --> 00:28:45,720 Speaker 1: against the background footage, and you had to combine that 490 00:28:46,040 --> 00:28:48,760 Speaker 1: combination of the background image and the traveling matt with 491 00:28:48,880 --> 00:28:52,760 Speaker 1: the fully processed color image and then ultimately come up 492 00:28:52,880 --> 00:28:59,680 Speaker 1: with a composite piece of film. It gave filmmakers way 493 00:28:59,680 --> 00:29:02,520 Speaker 1: more options when making movies. It allowed them to shoot 494 00:29:02,600 --> 00:29:06,239 Speaker 1: stuff inside a sound stage rather than whatever location they 495 00:29:06,240 --> 00:29:08,520 Speaker 1: would have to go to, and even opened upe locations 496 00:29:08,520 --> 00:29:11,600 Speaker 1: that would otherwise be impossible. But it did require a 497 00:29:11,640 --> 00:29:16,160 Speaker 1: lot of post production time and work. It also required 498 00:29:16,160 --> 00:29:18,920 Speaker 1: a close attention to lighting, otherwise you would end up 499 00:29:18,960 --> 00:29:21,880 Speaker 1: with blue halos around people and that was pretty darn 500 00:29:22,000 --> 00:29:27,120 Speaker 1: distracting effect. All of these different approaches required really good lighting, 501 00:29:27,160 --> 00:29:30,800 Speaker 1: sometimes really intense lighting, so it would also create pretty 502 00:29:30,920 --> 00:29:34,000 Speaker 1: uncomfortable shooting conditions that would get really hot in those 503 00:29:34,000 --> 00:29:37,760 Speaker 1: sound stages. So while it was phenomenal technology. It required 504 00:29:37,760 --> 00:29:40,160 Speaker 1: a lot of finesse to use it properly, and a 505 00:29:40,240 --> 00:29:44,600 Speaker 1: human touch was absolutely necessary through every stage of the process. Now, 506 00:29:44,640 --> 00:29:49,240 Speaker 1: over the next several years, really decades, movies benefited from 507 00:29:49,240 --> 00:29:52,920 Speaker 1: this technology. The tech allowed filmmakers to do all sorts 508 00:29:52,960 --> 00:29:55,440 Speaker 1: of neat things. Not only could they make it seem 509 00:29:55,480 --> 00:29:58,160 Speaker 1: like actors were in places that would be hard or 510 00:29:58,200 --> 00:30:01,360 Speaker 1: difficult to shoot in or places it maybe don't even exist, 511 00:30:01,960 --> 00:30:05,600 Speaker 1: they also allowed for stuff like the incorporation of animation 512 00:30:05,720 --> 00:30:09,719 Speaker 1: and live action in a way that wasn't really possible before. 513 00:30:10,200 --> 00:30:12,800 Speaker 1: I'll get back to that again in a second. But 514 00:30:12,880 --> 00:30:16,760 Speaker 1: in the early nineteen fifties, Eastman Kodak created the color 515 00:30:16,880 --> 00:30:20,880 Speaker 1: motion picture film that simplified the process of shooting on 516 00:30:20,960 --> 00:30:24,240 Speaker 1: color significantly so, rather than exposing three strips of black 517 00:30:24,280 --> 00:30:26,720 Speaker 1: and white film two different bands of light, and then 518 00:30:26,800 --> 00:30:31,040 Speaker 1: processing them to create a composite color image, this new 519 00:30:31,080 --> 00:30:34,920 Speaker 1: film actually contained all the layers that corresponded to blue, green, 520 00:30:35,080 --> 00:30:40,320 Speaker 1: and red. They each had essentially filters and dies in them, 521 00:30:40,480 --> 00:30:43,240 Speaker 1: and each layer effectively had its own silver halide crystals 522 00:30:43,240 --> 00:30:46,120 Speaker 1: and respective dies and streamlining the process for shooting on 523 00:30:46,200 --> 00:30:49,240 Speaker 1: and developing color film you just had to have one strip, 524 00:30:49,480 --> 00:30:52,520 Speaker 1: not the tri strip approach of technic color. It really 525 00:30:52,600 --> 00:30:56,320 Speaker 1: changed things. Also, by tweaking the blue screen process, some 526 00:30:56,440 --> 00:30:59,040 Speaker 1: inventors were able to get spectacular results. This gets us 527 00:30:59,080 --> 00:31:02,160 Speaker 1: back to that live act an animation discussion. That would 528 00:31:02,200 --> 00:31:05,800 Speaker 1: be Petro Vlajos, who was the engineer who worked on 529 00:31:05,840 --> 00:31:10,120 Speaker 1: a little film called Mary Poppins in the early nineteen sixties. 530 00:31:10,520 --> 00:31:13,440 Speaker 1: Law Hosts wanted to improve upon the technology that Butler 531 00:31:13,480 --> 00:31:15,640 Speaker 1: had created, and one of the issues he sought to 532 00:31:15,680 --> 00:31:18,880 Speaker 1: address was that the color blue used for blue screens 533 00:31:19,000 --> 00:31:23,240 Speaker 1: wasn't a specific wavelength of light. You gotta remember that 534 00:31:23,400 --> 00:31:26,400 Speaker 1: the wavelength of light, or if you prefer the frequency 535 00:31:26,480 --> 00:31:30,480 Speaker 1: of light, the two are related, determines the lights color, 536 00:31:30,520 --> 00:31:33,640 Speaker 1: the color that we perceive, and the wavelengths corresponding to 537 00:31:33,640 --> 00:31:36,040 Speaker 1: the blue screens of the day ranged from four hundred 538 00:31:36,120 --> 00:31:40,280 Speaker 1: thirty five nanometers to five hundred nanometers, and that meant 539 00:31:40,320 --> 00:31:43,719 Speaker 1: any color blue that fell in or near that range 540 00:31:43,760 --> 00:31:47,120 Speaker 1: was awful limits for use in a scene. Vlahos figured 541 00:31:47,120 --> 00:31:48,800 Speaker 1: there had to be a better way, and he decided 542 00:31:48,840 --> 00:31:53,000 Speaker 1: to use a different backdrop color entirely yellow, but not 543 00:31:53,120 --> 00:31:56,880 Speaker 1: just any yellow. He wanted a precise yellow, the yellow 544 00:31:56,920 --> 00:32:01,120 Speaker 1: that comes from sodium gas discharge lamps. When you excite 545 00:32:01,120 --> 00:32:04,960 Speaker 1: sodium gas, essentially when you energize it with electricity, the 546 00:32:05,000 --> 00:32:08,080 Speaker 1: gas gives off a distinct yellow light with a wavelength 547 00:32:08,080 --> 00:32:11,680 Speaker 1: of five nine nanometers. As long as nothing in the 548 00:32:11,720 --> 00:32:15,400 Speaker 1: camera frame matches that precise shade of yellow, you could 549 00:32:15,400 --> 00:32:18,320 Speaker 1: have all sorts of colors in the shot, including different 550 00:32:18,440 --> 00:32:21,600 Speaker 1: shades of yellow, and not have to worry about skimping 551 00:32:21,920 --> 00:32:25,840 Speaker 1: on things like blue costume pieces. Paired with this was 552 00:32:25,880 --> 00:32:29,200 Speaker 1: a customized camera that contained a prism that could isolate 553 00:32:29,280 --> 00:32:32,880 Speaker 1: the five nine wavelength of light. Vlaw host was able 554 00:32:32,880 --> 00:32:37,120 Speaker 1: to produce an incredibly precise and accurate traveling matt this way, 555 00:32:37,160 --> 00:32:40,560 Speaker 1: which meant Disney could place actors on any separate background 556 00:32:40,560 --> 00:32:43,520 Speaker 1: without worrying about the effect showing at the seams. In fact, 557 00:32:43,960 --> 00:32:46,240 Speaker 1: in one sequence, Mary Poppins is wearing a hat that 558 00:32:46,280 --> 00:32:49,320 Speaker 1: has this veil like material on it, and you can 559 00:32:49,360 --> 00:32:52,920 Speaker 1: actually see the background, the anime background, through the veil, 560 00:32:53,240 --> 00:32:56,920 Speaker 1: and that's because of the precision of this approach. There 561 00:32:57,000 --> 00:32:59,760 Speaker 1: was one small hiccup, which was that vlaw host only 562 00:32:59,800 --> 00:33:04,680 Speaker 1: had one working prism that could isolate this specific band 563 00:33:04,720 --> 00:33:08,760 Speaker 1: of light. This fi nine nanometer band of light, so 564 00:33:08,920 --> 00:33:12,960 Speaker 1: they only had one sodium vapor camera as a result. Now, 565 00:33:13,000 --> 00:33:15,920 Speaker 1: when we come back, we're going to look at the 566 00:33:16,040 --> 00:33:20,080 Speaker 1: further evolution of this technology, including how it has changed 567 00:33:20,200 --> 00:33:23,560 Speaker 1: once the digital realm became a reality. But first let's 568 00:33:23,600 --> 00:33:33,800 Speaker 1: take another quick break. I've stuck with the film world 569 00:33:33,920 --> 00:33:35,880 Speaker 1: for this podcast so far, but I also have to 570 00:33:35,880 --> 00:33:38,760 Speaker 1: talk about the use of chroma key technology in the 571 00:33:38,800 --> 00:33:41,520 Speaker 1: world of live television. See Mary Poppins came out in 572 00:33:41,600 --> 00:33:44,240 Speaker 1: nineteen sixty four, but the first use of chroma key 573 00:33:44,280 --> 00:33:47,680 Speaker 1: on live TV was in the late nineteen fifties. This 574 00:33:47,760 --> 00:33:50,800 Speaker 1: is the same technology that would become the basis for 575 00:33:51,040 --> 00:33:54,720 Speaker 1: TV weather reports, where the meteorologist stands in front of 576 00:33:54,720 --> 00:33:58,040 Speaker 1: a wall which seems to have a dynamic map on 577 00:33:58,080 --> 00:34:00,560 Speaker 1: it that can change from one image to the next. 578 00:34:01,000 --> 00:34:04,360 Speaker 1: But if the process I've described required so many steps, 579 00:34:04,400 --> 00:34:07,200 Speaker 1: if you had to do so much post production on 580 00:34:07,240 --> 00:34:10,040 Speaker 1: the film, how could you take that same basic idea 581 00:34:10,120 --> 00:34:12,680 Speaker 1: and make it work in the realm of television in 582 00:34:12,760 --> 00:34:17,439 Speaker 1: real time live broadcast. Frank Gaskins and Mitt Altman led 583 00:34:17,560 --> 00:34:21,040 Speaker 1: this effort at NBC in the nineteen fifties. They created 584 00:34:21,080 --> 00:34:24,680 Speaker 1: a television camera approach to chromakey and tested it out 585 00:34:24,840 --> 00:34:28,600 Speaker 1: in nineteen fifty seven with a live broadcast of Matinee Theater. 586 00:34:28,960 --> 00:34:32,400 Speaker 1: The specific story they chose to serve as the first 587 00:34:32,440 --> 00:34:36,640 Speaker 1: experiment here was an adaptation of The Invisible Man, and 588 00:34:36,719 --> 00:34:40,279 Speaker 1: that was fitting because the nineteen thirty three film adaptation 589 00:34:40,360 --> 00:34:42,640 Speaker 1: of The Invisible Man had relied heavily on the old 590 00:34:42,640 --> 00:34:48,800 Speaker 1: Williams process. The live television version initially relied on two cameras. 591 00:34:49,239 --> 00:34:53,560 Speaker 1: One camera would capture a background image. The other camera 592 00:34:53,680 --> 00:34:56,120 Speaker 1: would be the foreground camera that would be for all 593 00:34:56,160 --> 00:34:59,360 Speaker 1: the action in the sequence, and behind all this action 594 00:34:59,400 --> 00:35:02,600 Speaker 1: would be a lou backdrop. Combining these two sets of 595 00:35:02,640 --> 00:35:07,000 Speaker 1: images simultaneously in a device called a chroma key amplifier 596 00:35:07,400 --> 00:35:12,040 Speaker 1: would create a live composite video feed. Engineers at our 597 00:35:12,120 --> 00:35:14,279 Speaker 1: c A created the actual technology, and I think it's 598 00:35:14,320 --> 00:35:18,160 Speaker 1: best if I just quote directly from the nineteen edition 599 00:35:18,400 --> 00:35:22,560 Speaker 1: of the journal Electronic Age that describes this process. So 600 00:35:22,680 --> 00:35:26,080 Speaker 1: here's a quote. A switching signal or a color key 601 00:35:26,440 --> 00:35:29,960 Speaker 1: used in association with the special effects amplifier controls the 602 00:35:30,040 --> 00:35:33,440 Speaker 1: signals sent out over the air. The switching signal is 603 00:35:33,480 --> 00:35:36,960 Speaker 1: in turn created by the camera photographing the live action 604 00:35:37,080 --> 00:35:40,080 Speaker 1: in front of the blue screen. While the camera is 605 00:35:40,120 --> 00:35:44,400 Speaker 1: scanning the blue screen, the switching device automatically activates the 606 00:35:44,560 --> 00:35:48,440 Speaker 1: second camera, which projects the background. When the scanning signal 607 00:35:48,480 --> 00:35:51,680 Speaker 1: reaches an area covered by the live actors, the switching 608 00:35:51,719 --> 00:35:55,239 Speaker 1: device turns off the camera projecting the background material and 609 00:35:55,320 --> 00:35:59,240 Speaker 1: transmits the action. Now that's the end of that quote. 610 00:35:59,280 --> 00:36:02,839 Speaker 1: You could also feed images directly to the chroma key amplifier. 611 00:36:02,840 --> 00:36:04,920 Speaker 1: It didn't have to be a live video from a 612 00:36:05,000 --> 00:36:08,439 Speaker 1: second camera, so you could provide an image like a map, 613 00:36:08,800 --> 00:36:11,400 Speaker 1: allowing a meteorologist to stand in front of it otherwise 614 00:36:11,600 --> 00:36:15,200 Speaker 1: blank blue or green screen and gesture at various regions. 615 00:36:15,560 --> 00:36:18,239 Speaker 1: The audience at home would see the meteorologist appearing to 616 00:36:18,280 --> 00:36:20,800 Speaker 1: stand in front of the map, or maybe a summary 617 00:36:20,800 --> 00:36:23,399 Speaker 1: of the forecasted whether for the week, and not just 618 00:36:23,640 --> 00:36:27,320 Speaker 1: a blue screen or a green screen. Around the nineteen seventies, 619 00:36:27,760 --> 00:36:30,480 Speaker 1: that's when we started to see a gradual shift, particularly 620 00:36:30,640 --> 00:36:35,160 Speaker 1: in television, from blue screens to green ones. Part of 621 00:36:35,200 --> 00:36:38,960 Speaker 1: that was because of a very slow transition into digital technology. 622 00:36:39,000 --> 00:36:42,080 Speaker 1: It would become more important as digital cameras became a thing. 623 00:36:42,480 --> 00:36:46,760 Speaker 1: Digital cameras were better attuned to doing this with greens 624 00:36:46,960 --> 00:36:50,160 Speaker 1: rather than with blues, although you can do either. But 625 00:36:50,239 --> 00:36:53,640 Speaker 1: another big reason was just that people don't tend to 626 00:36:53,640 --> 00:36:56,520 Speaker 1: wear a lot of green, whereas blue was a pretty 627 00:36:56,719 --> 00:36:59,200 Speaker 1: and still is a pretty popular color. And once in 628 00:36:59,239 --> 00:37:01,600 Speaker 1: a while, so when on camera would forget that they're 629 00:37:01,600 --> 00:37:03,879 Speaker 1: wearing blue, and then they'd step in front a blue 630 00:37:03,920 --> 00:37:07,279 Speaker 1: screen and suddenly their jacket or their shirt or their 631 00:37:07,320 --> 00:37:10,759 Speaker 1: tie or whatever would become part of the background image. 632 00:37:11,239 --> 00:37:14,319 Speaker 1: Back to film for a moment. We're gonna leave TV 633 00:37:14,440 --> 00:37:18,800 Speaker 1: for a second. In nineteen eighty a guy named Richard Edlund, 634 00:37:18,840 --> 00:37:21,759 Speaker 1: who worked on a little film called The Umpire Strikes Back, 635 00:37:22,160 --> 00:37:25,960 Speaker 1: made another big contribution to the chroma key process. Edlund 636 00:37:26,000 --> 00:37:30,120 Speaker 1: developed a quad optical printer which both sped up the 637 00:37:30,200 --> 00:37:34,040 Speaker 1: process for producing composite film shots and also brought the 638 00:37:34,080 --> 00:37:36,960 Speaker 1: price down as well. I mean, if you think about it, 639 00:37:37,080 --> 00:37:42,120 Speaker 1: saving time means saving money. He also developed a computer 640 00:37:42,239 --> 00:37:46,480 Speaker 1: controlled system of cameras which allowed for very precise camera movements, 641 00:37:46,520 --> 00:37:49,920 Speaker 1: and that meant you could create choreographed shots of foreground 642 00:37:50,120 --> 00:37:53,719 Speaker 1: and background and composite them together and have the match 643 00:37:53,800 --> 00:37:57,480 Speaker 1: up perfectly. It was also really effective for processing images 644 00:37:57,560 --> 00:38:00,799 Speaker 1: that were shot with miniatures, which was done a lot 645 00:38:00,880 --> 00:38:03,680 Speaker 1: in the original Star Wars series, so it was still 646 00:38:03,719 --> 00:38:06,759 Speaker 1: a painstaking process, but now a lot more could be 647 00:38:06,840 --> 00:38:10,520 Speaker 1: done on one piece of equipment per pass, as opposed 648 00:38:10,560 --> 00:38:12,680 Speaker 1: to having to do a process on the piece of 649 00:38:12,680 --> 00:38:15,959 Speaker 1: equipment then do it again and then again and again 650 00:38:16,000 --> 00:38:19,640 Speaker 1: until you finally got whatever result you were after. Gradually, 651 00:38:19,960 --> 00:38:23,160 Speaker 1: computer software would creep into the realm of film and 652 00:38:23,280 --> 00:38:25,680 Speaker 1: video effects, and this leads us to a version of 653 00:38:25,760 --> 00:38:29,400 Speaker 1: chroma key that I think is actually the easiest to understand. 654 00:38:29,480 --> 00:38:34,439 Speaker 1: It's it's technically advanced, but the principle is simple. So 655 00:38:34,560 --> 00:38:37,440 Speaker 1: let's say that you want to do a Twitch stream 656 00:38:37,600 --> 00:38:39,839 Speaker 1: and you're playing a video game live, and you want 657 00:38:39,880 --> 00:38:43,279 Speaker 1: your viewers to see you sitting in front of the 658 00:38:43,360 --> 00:38:47,880 Speaker 1: video game footage. So wants to make a dynamic background 659 00:38:48,000 --> 00:38:50,719 Speaker 1: of video gameplay behind you. So you go out and 660 00:38:50,719 --> 00:38:52,719 Speaker 1: you buy a green screen and you set it up 661 00:38:52,760 --> 00:38:56,080 Speaker 1: behind your gaming chair, You throw up some lights. More 662 00:38:56,120 --> 00:38:58,920 Speaker 1: on that in a second, and you launch a program 663 00:38:59,040 --> 00:39:02,520 Speaker 1: that will insert your video game capture as a custom 664 00:39:02,680 --> 00:39:06,440 Speaker 1: digital background. Your viewers will see you sitting in front 665 00:39:06,480 --> 00:39:09,200 Speaker 1: of a screen otherwise filled with I don't know, Skyrim 666 00:39:09,360 --> 00:39:12,640 Speaker 1: or Minecraft or the untitled Goose game or whatever it 667 00:39:12,719 --> 00:39:17,479 Speaker 1: is you're playing. What's going on on a technical level, Well, 668 00:39:17,520 --> 00:39:21,080 Speaker 1: the digital world is different from the analog world in 669 00:39:21,160 --> 00:39:24,919 Speaker 1: lots of ways, But importantly for our discussion, it comes 670 00:39:24,920 --> 00:39:29,000 Speaker 1: down to how in the digital world everything ultimately boils 671 00:39:29,040 --> 00:39:33,360 Speaker 1: down to numeric values. You or I could have a 672 00:39:33,400 --> 00:39:39,200 Speaker 1: debate about whether a particular color is aquamarine versus arrow blue, 673 00:39:39,400 --> 00:39:42,759 Speaker 1: versus blue green versus dark cyan, or whatever it may be. 674 00:39:43,520 --> 00:39:47,160 Speaker 1: But in the digital world, every color ultimately has a 675 00:39:47,280 --> 00:39:52,920 Speaker 1: numeric value. Assuming whatever we're looking at is a solid color, 676 00:39:53,520 --> 00:39:56,720 Speaker 1: you could designate that solid color with a specific numeric 677 00:39:56,840 --> 00:40:00,800 Speaker 1: value in computer software and then replicated it or immediately 678 00:40:00,840 --> 00:40:04,399 Speaker 1: identify it within any scene you might see where I'm 679 00:40:04,440 --> 00:40:08,520 Speaker 1: going here. With video software, you can designate a specific 680 00:40:08,520 --> 00:40:12,680 Speaker 1: color from one video source. Uh, this specific color is 681 00:40:12,760 --> 00:40:16,760 Speaker 1: the chroma, as it were, and this is the color 682 00:40:16,840 --> 00:40:20,920 Speaker 1: you want to replace or key out. The video software 683 00:40:21,000 --> 00:40:24,880 Speaker 1: analyzes information that's coming from say a digital camera feed 684 00:40:24,920 --> 00:40:28,239 Speaker 1: into your computer, and it looks for any signals that 685 00:40:28,400 --> 00:40:31,719 Speaker 1: map to the value or values of the color or 686 00:40:31,800 --> 00:40:35,719 Speaker 1: colors you've picked. Most software lets you fine tune this 687 00:40:35,920 --> 00:40:38,400 Speaker 1: so you can adjust the settings to hone in on 688 00:40:38,520 --> 00:40:41,360 Speaker 1: the specific shade of green or blue or whatever it 689 00:40:41,440 --> 00:40:44,560 Speaker 1: is that you plan to key out. Anything that matches 690 00:40:44,640 --> 00:40:48,640 Speaker 1: that value or range of values then gets turned into 691 00:40:48,719 --> 00:40:53,680 Speaker 1: a transparent video layer. The secondary image. In our case, 692 00:40:54,040 --> 00:40:57,720 Speaker 1: the video game footage that we're creating as we're playing 693 00:40:57,760 --> 00:41:01,640 Speaker 1: this game shows through this transparent layer, and you can 694 00:41:01,680 --> 00:41:05,360 Speaker 1: actually think of the foreground video as an overlay on 695 00:41:05,520 --> 00:41:10,160 Speaker 1: top of the digital background layer the video game footage. 696 00:41:10,480 --> 00:41:16,000 Speaker 1: Anything transparent in that overlay will show the background through 697 00:41:16,600 --> 00:41:20,880 Speaker 1: the solid stuff. Presumably you, the Twitch player, will block 698 00:41:21,239 --> 00:41:24,560 Speaker 1: the background image, so viewers will be able to see 699 00:41:24,560 --> 00:41:27,359 Speaker 1: their favorite Twitch streamer sitting in front of a video game. 700 00:41:27,760 --> 00:41:30,360 Speaker 1: The software does all the work for you, creating the 701 00:41:30,400 --> 00:41:33,920 Speaker 1: composite video feed that the viewer sees. That software, by 702 00:41:33,920 --> 00:41:38,200 Speaker 1: the way, isn't Twitch itself. Twitch is a video streaming platform, 703 00:41:38,480 --> 00:41:41,040 Speaker 1: but to actually do these sort of effects, you'd need 704 00:41:41,080 --> 00:41:43,279 Speaker 1: to use some other piece of software, such as some 705 00:41:43,440 --> 00:41:47,239 Speaker 1: version of Open Broadcasters Software or o b S, And 706 00:41:47,280 --> 00:41:49,879 Speaker 1: there are a lot of different versions of video broadcasting 707 00:41:49,880 --> 00:41:53,760 Speaker 1: software available for folks to play with, from free stuff 708 00:41:53,800 --> 00:41:57,080 Speaker 1: to professional grade stuff. This type of versatility is the 709 00:41:57,160 --> 00:41:59,000 Speaker 1: kind of stuff that previously you would have had to 710 00:41:59,080 --> 00:42:01,880 Speaker 1: have worked in like a TV studio to have access to, 711 00:42:02,000 --> 00:42:05,759 Speaker 1: but now anyone with a sufficiently beefy computer can run 712 00:42:05,840 --> 00:42:08,719 Speaker 1: this kind of operation. For this to work well, you 713 00:42:08,840 --> 00:42:12,359 Speaker 1: want to have really good lighting, both for the foreground 714 00:42:12,480 --> 00:42:15,759 Speaker 1: and for the background drop. You want the lighting on 715 00:42:15,840 --> 00:42:18,400 Speaker 1: the green screen you're using to be nice and even, 716 00:42:18,520 --> 00:42:21,480 Speaker 1: and you want to eliminate any shadows, because if you're 717 00:42:21,480 --> 00:42:26,080 Speaker 1: casting a shadow on the green screen, the camera will 718 00:42:26,120 --> 00:42:28,080 Speaker 1: pick up that part of the green screen as being 719 00:42:28,080 --> 00:42:31,439 Speaker 1: a darker color, and it might even be dark enough 720 00:42:31,560 --> 00:42:34,800 Speaker 1: that the video software doesn't identify it as the color 721 00:42:34,880 --> 00:42:37,720 Speaker 1: that you want to key out. So in those cases 722 00:42:37,719 --> 00:42:40,200 Speaker 1: you would get these weird video artifacts on screen as 723 00:42:40,200 --> 00:42:42,839 Speaker 1: a result, it be really distracting. So ideally you want 724 00:42:42,960 --> 00:42:46,759 Speaker 1: lights that will illuminate the green screen evenly and are 725 00:42:46,840 --> 00:42:50,680 Speaker 1: dedicated just for that purpose. If you're lighting yourself directly 726 00:42:50,760 --> 00:42:52,840 Speaker 1: from the front, you're not using a ring light or 727 00:42:52,880 --> 00:42:55,080 Speaker 1: anything like that, then you're gonna be casting a shadow 728 00:42:55,160 --> 00:42:59,160 Speaker 1: behind you, unless you're Peter Pan, in which case I 729 00:42:59,200 --> 00:43:03,120 Speaker 1: guess you just think cappy thoughts. Now, this flies for 730 00:43:03,160 --> 00:43:06,680 Speaker 1: stuff like zoom meetings and Twitch streams, but when it 731 00:43:06,719 --> 00:43:10,640 Speaker 1: comes to professional grade film, it's not really up to snuff. 732 00:43:11,040 --> 00:43:13,759 Speaker 1: Software can do a bulk of the work, but good 733 00:43:13,800 --> 00:43:16,279 Speaker 1: old human effects artists are still needed to make sure 734 00:43:16,280 --> 00:43:18,839 Speaker 1: everything is coming out well. They can step in and 735 00:43:18,880 --> 00:43:22,279 Speaker 1: do some quality control. They can tweak things, they can 736 00:43:22,360 --> 00:43:24,839 Speaker 1: fix any issues that pop up, and that pays off. 737 00:43:25,200 --> 00:43:28,759 Speaker 1: You've probably seen a movie that had phenomenal attention to 738 00:43:28,840 --> 00:43:31,799 Speaker 1: this process and the effects are top notch. And you've 739 00:43:31,840 --> 00:43:34,840 Speaker 1: probably seen other movies where, due to whatever reason, maybe 740 00:43:34,840 --> 00:43:37,040 Speaker 1: it was budget, maybe it's just the talent of the 741 00:43:37,080 --> 00:43:39,719 Speaker 1: people working on it, you could tell that such care 742 00:43:39,960 --> 00:43:42,920 Speaker 1: wasn't given to the process and it shows in the 743 00:43:42,960 --> 00:43:46,520 Speaker 1: final product. I still think films like Jurassic Park I'm 744 00:43:46,520 --> 00:43:50,640 Speaker 1: talking about the original Jurassic Park hold up pretty darn well. 745 00:43:50,920 --> 00:43:53,160 Speaker 1: And part of that is that the movie depended on 746 00:43:53,480 --> 00:43:56,360 Speaker 1: a mixture of different effects. Some of them were computer 747 00:43:56,440 --> 00:44:00,319 Speaker 1: generated and keyed in, some were robotic effect x But 748 00:44:00,600 --> 00:44:02,000 Speaker 1: a lot of this has to do with the fact 749 00:44:02,040 --> 00:44:05,600 Speaker 1: that the effects team as a whole took tremendous care 750 00:44:05,680 --> 00:44:08,720 Speaker 1: to produce results that were really convincing to the eye. 751 00:44:09,040 --> 00:44:12,560 Speaker 1: And that's the story behind chroma key and green or 752 00:44:12,680 --> 00:44:16,560 Speaker 1: blue screen technology. It's a super interesting approach to creating 753 00:44:16,600 --> 00:44:20,279 Speaker 1: a composite moving image. And frankly, there's gonna be a 754 00:44:20,360 --> 00:44:23,600 Speaker 1: lot of other topics around this that I can go into. 755 00:44:23,680 --> 00:44:27,160 Speaker 1: I could probably talk even more about optical printers, for example, 756 00:44:27,600 --> 00:44:31,560 Speaker 1: and the various approaches to film processing. And you can 757 00:44:31,600 --> 00:44:34,560 Speaker 1: see that while the actual chroma key process is very 758 00:44:34,600 --> 00:44:38,400 Speaker 1: different between film and digital video, the basic idea of 759 00:44:38,440 --> 00:44:41,960 Speaker 1: replacing one color or one element in a shot was 760 00:44:42,120 --> 00:44:46,600 Speaker 1: something from a totally different source remains the same. It's 761 00:44:46,640 --> 00:44:50,480 Speaker 1: the same underlying principle no matter what the actual process is. 762 00:44:51,520 --> 00:44:54,040 Speaker 1: If you guys have suggestions for future topics I should 763 00:44:54,080 --> 00:44:56,680 Speaker 1: cover here on tech stuff, whether it's a specific technology, 764 00:44:56,920 --> 00:45:00,520 Speaker 1: a company in tech, a personality in tech, maybe it's 765 00:45:00,560 --> 00:45:03,759 Speaker 1: just a trend in tech in general, reach out to 766 00:45:03,800 --> 00:45:06,200 Speaker 1: me let me know what I should cover. You can 767 00:45:06,360 --> 00:45:09,279 Speaker 1: get in touch through Twitter or Facebook. The hand over 768 00:45:09,400 --> 00:45:12,920 Speaker 1: both of those is text stuff H s W and 769 00:45:13,000 --> 00:45:21,279 Speaker 1: I'll talk to you again really soon. Text Stuff is 770 00:45:21,320 --> 00:45:24,440 Speaker 1: an I Heart Radio production. For more podcasts from My 771 00:45:24,600 --> 00:45:28,200 Speaker 1: Heart Radio, visit the I Heart Radio app, Apple Podcasts, 772 00:45:28,320 --> 00:45:30,280 Speaker 1: or wherever you listen to your favorite shows.