1 00:00:04,440 --> 00:00:12,879 Speaker 1: Welcome to tech Stuff, a production from iHeartRadio. Hey Thearon, 2 00:00:13,039 --> 00:00:16,320 Speaker 1: Welcome to tech Stuff. I'm your host, Jonathan Strickland. I'm 3 00:00:16,360 --> 00:00:19,400 Speaker 1: an executive producer with iHeart Podcasts. And how the tech 4 00:00:19,440 --> 00:00:22,080 Speaker 1: are you well? Here in the United States, we are 5 00:00:22,120 --> 00:00:26,479 Speaker 1: celebrating Thanksgiving, which means our office is closed, so I 6 00:00:26,520 --> 00:00:29,440 Speaker 1: do not have a brand new episode for you, but 7 00:00:29,560 --> 00:00:32,440 Speaker 1: I do have a pretty cool episode that we published 8 00:00:32,479 --> 00:00:36,600 Speaker 1: on June one, twenty twenty. It is titled tech Stuff 9 00:00:36,760 --> 00:00:40,720 Speaker 1: in front of a Green Screen. So I hope you enjoy. 10 00:00:40,800 --> 00:00:43,520 Speaker 1: And for those of you who are celebrating, Happy Thanksgiving, 11 00:00:44,440 --> 00:00:46,640 Speaker 1: and for those of y'all not in the United States, 12 00:00:46,960 --> 00:00:50,120 Speaker 1: maybe in Canada where you had Thanksgiving already. To you, 13 00:00:50,240 --> 00:00:55,320 Speaker 1: I say happy Thursday, enjoy this rerun episode of tech Stuff. 14 00:00:58,440 --> 00:01:04,600 Speaker 1: Today's topic goes by many names like chroma key, or 15 00:01:04,720 --> 00:01:09,559 Speaker 1: blue screen or green screen. The inventor of this technology 16 00:01:09,600 --> 00:01:14,600 Speaker 1: developed it for film, and that pun was unintentional, you know, 17 00:01:15,120 --> 00:01:19,640 Speaker 1: developed for film, but I'm gonna run with it. Today 18 00:01:19,800 --> 00:01:25,120 Speaker 1: we use this technology in film, in television, on Twitch streams, 19 00:01:25,160 --> 00:01:27,760 Speaker 1: and zoom calls, I mean all over the place. And 20 00:01:27,800 --> 00:01:30,560 Speaker 1: in the old days you weren't likely to encounter a 21 00:01:30,600 --> 00:01:35,200 Speaker 1: green screen unless you were inside a movie studio, like 22 00:01:35,720 --> 00:01:38,640 Speaker 1: inside a soundstage. But today there are a lot of 23 00:01:38,680 --> 00:01:41,080 Speaker 1: folks who have a green screen just stashed in their 24 00:01:41,120 --> 00:01:44,440 Speaker 1: home office. So today I want to cover this technology, 25 00:01:44,760 --> 00:01:48,560 Speaker 1: it's history and development and how it works. Now, before 26 00:01:48,560 --> 00:01:51,559 Speaker 1: I get into the history, which, as I'm sure most 27 00:01:51,560 --> 00:01:56,280 Speaker 1: of you know, is my modus oparandi, let's give a 28 00:01:56,360 --> 00:02:01,080 Speaker 1: quick overview of what this technology actually does. So it's 29 00:02:01,160 --> 00:02:05,880 Speaker 1: a system that allows a creator to insert images, typically 30 00:02:06,080 --> 00:02:09,760 Speaker 1: a background that's your standard use of this, and you 31 00:02:09,840 --> 00:02:13,200 Speaker 1: do it into a shot that otherwise isn't actually in 32 00:02:13,280 --> 00:02:16,760 Speaker 1: that location, so it could be a static image, or 33 00:02:16,840 --> 00:02:19,239 Speaker 1: the new image might be in motion itself, so it 34 00:02:19,320 --> 00:02:22,560 Speaker 1: might be video or film. This technology allows creators to 35 00:02:22,600 --> 00:02:25,360 Speaker 1: shoot in locations they might otherwise have trouble getting to, 36 00:02:25,639 --> 00:02:28,640 Speaker 1: like the bottom of the ocean or an outer space, 37 00:02:28,800 --> 00:02:32,000 Speaker 1: or in my old college dorm room because I was 38 00:02:32,040 --> 00:02:35,120 Speaker 1: notorious for locking myself out. So when you do it well, 39 00:02:35,520 --> 00:02:39,520 Speaker 1: it really enhances a scene. But when done poorly, it's 40 00:02:39,560 --> 00:02:43,400 Speaker 1: incredibly distracting because it's so obvious that the people or 41 00:02:43,440 --> 00:02:46,040 Speaker 1: you know whatever that are in the foreground of the 42 00:02:46,080 --> 00:02:49,920 Speaker 1: shot aren't actually in whatever the environment is. But that's 43 00:02:49,960 --> 00:02:54,400 Speaker 1: the basic idea. It's to create a composite, a combination 44 00:02:54,760 --> 00:02:59,160 Speaker 1: of multiple shots into a single new shot, so that 45 00:02:59,400 --> 00:03:03,239 Speaker 1: the component and it's from those two separate shots are 46 00:03:03,840 --> 00:03:06,200 Speaker 1: combined as if they're in the same place at the 47 00:03:06,200 --> 00:03:09,520 Speaker 1: same time. That's the basic idea. Now let's get to 48 00:03:09,639 --> 00:03:12,720 Speaker 1: the history, you know, the part that everyone really came 49 00:03:12,760 --> 00:03:16,480 Speaker 1: here for. But before we even get into the development 50 00:03:16,520 --> 00:03:18,880 Speaker 1: of it, we need to think about the early days 51 00:03:18,919 --> 00:03:22,640 Speaker 1: of film and talk about what film really is, because 52 00:03:22,680 --> 00:03:24,720 Speaker 1: that's going to help us understand the evolution of the 53 00:03:24,840 --> 00:03:28,960 Speaker 1: art form that made chroma key even a possibility. When 54 00:03:29,000 --> 00:03:32,959 Speaker 1: I say film in this case, I'm specifically referencing images 55 00:03:33,080 --> 00:03:36,640 Speaker 1: shot on a long strip of plastic upon which there 56 00:03:36,680 --> 00:03:40,520 Speaker 1: is a coating of light sensitive chemicals. Actually, there are 57 00:03:40,560 --> 00:03:44,520 Speaker 1: several layers of light sensitive particles in that thin strip 58 00:03:44,600 --> 00:03:47,160 Speaker 1: of film. You know, with modern film you might be 59 00:03:47,200 --> 00:03:51,080 Speaker 1: talking about twenty or more layers on that thin little 60 00:03:51,080 --> 00:03:54,680 Speaker 1: piece of plastic. These layers include binding agents, you know, 61 00:03:54,920 --> 00:03:59,720 Speaker 1: essentially gelatine and grains of silver halid crystals, which react 62 00:03:59,720 --> 00:04:03,400 Speaker 1: to the light. These are those photosensitive chemicals and also 63 00:04:03,520 --> 00:04:06,800 Speaker 1: some special molecules that bind with silver haylid crystal so 64 00:04:06,840 --> 00:04:10,760 Speaker 1: that they transfer energy from specific wavelengths of light, which 65 00:04:11,080 --> 00:04:15,720 Speaker 1: we perceive as different colors. When light hits the silver 66 00:04:15,800 --> 00:04:20,160 Speaker 1: haylight crystals coating this plastic, there is a chemical reaction, 67 00:04:20,480 --> 00:04:23,039 Speaker 1: and you can think of it as a chemical record 68 00:04:23,400 --> 00:04:26,880 Speaker 1: of that instant of time. Whatever light hit the film 69 00:04:27,279 --> 00:04:31,240 Speaker 1: is recorded there on this piece of plastic. So if 70 00:04:31,240 --> 00:04:34,680 Speaker 1: you position the lenses so that you can direct specific 71 00:04:34,800 --> 00:04:38,359 Speaker 1: light to that film, you can take a photograph. You 72 00:04:38,440 --> 00:04:41,520 Speaker 1: must use some form of shutter to block out the 73 00:04:41,600 --> 00:04:44,200 Speaker 1: light until you are ready to take your image. Then 74 00:04:44,240 --> 00:04:47,840 Speaker 1: you open the shutter. This exposes that piece of film 75 00:04:47,960 --> 00:04:50,760 Speaker 1: to the light that's being reflected off of whatever it 76 00:04:50,800 --> 00:04:54,159 Speaker 1: is you're photographing. Remember when we see things, we're seeing 77 00:04:54,240 --> 00:04:57,599 Speaker 1: light bouncing off of that and the color of the 78 00:04:57,600 --> 00:05:01,599 Speaker 1: stuff we see is dependent upon and which frequencies of 79 00:05:01,800 --> 00:05:06,360 Speaker 1: light bounce off of that thing. So then the shutter 80 00:05:06,440 --> 00:05:09,320 Speaker 1: closes on your camera and you've got your chemical record. 81 00:05:09,560 --> 00:05:12,440 Speaker 1: And the shutter is necessary because, as I said, these 82 00:05:12,520 --> 00:05:15,560 Speaker 1: chemicals react to light. If you just had this stuff 83 00:05:15,600 --> 00:05:19,120 Speaker 1: exposed to light all the time, it would have already reacted. 84 00:05:19,120 --> 00:05:20,640 Speaker 1: You would not be able to use it to take 85 00:05:20,680 --> 00:05:23,360 Speaker 1: a photograph of anything if you want to learn more 86 00:05:23,400 --> 00:05:27,760 Speaker 1: about this process, which is fascinating, but really the process 87 00:05:27,800 --> 00:05:30,039 Speaker 1: of photography is far enough out of the scope of 88 00:05:30,040 --> 00:05:32,280 Speaker 1: this episode that I don't want to go into it 89 00:05:32,480 --> 00:05:37,279 Speaker 1: much further. I do recommend you go to HowStuffWorks dot com. 90 00:05:37,320 --> 00:05:40,760 Speaker 1: That's my old employer. I don't technically work for How 91 00:05:40,760 --> 00:05:44,080 Speaker 1: Stuff Works anymore, but you can go to that website 92 00:05:44,240 --> 00:05:47,679 Speaker 1: and you look up the article how Photographic Film Works. 93 00:05:47,920 --> 00:05:50,640 Speaker 1: It was written by Chuck Woodworth and it's a great 94 00:05:50,800 --> 00:05:53,920 Speaker 1: example of the how Stuffworks style, and it goes into 95 00:05:53,960 --> 00:05:58,120 Speaker 1: the chemistry and physics of the photographic process, but we'll 96 00:05:58,160 --> 00:06:00,240 Speaker 1: skim over the rest of that for the purpose of 97 00:06:00,279 --> 00:06:04,000 Speaker 1: this episode. So now the film on the camera has 98 00:06:04,080 --> 00:06:07,480 Speaker 1: a latent image on it, and it represents the moment 99 00:06:07,640 --> 00:06:10,880 Speaker 1: in time the shutter allowed light to pass from the 100 00:06:10,960 --> 00:06:14,440 Speaker 1: lens to hit the film. But in a film camera, 101 00:06:14,600 --> 00:06:18,919 Speaker 1: a cinema camera, you're talking about a series of latent images. 102 00:06:19,560 --> 00:06:23,919 Speaker 1: Motors pull this strip of film at a steady speed 103 00:06:24,520 --> 00:06:27,760 Speaker 1: through the frame of the camera, where the shutter opens 104 00:06:27,760 --> 00:06:33,200 Speaker 1: and closes at a regular frequency, and the standard speed 105 00:06:33,640 --> 00:06:38,039 Speaker 1: of capturing images is twenty four frames per second. So 106 00:06:38,120 --> 00:06:43,040 Speaker 1: a film camera is capturing twenty four photographs every second. 107 00:06:43,160 --> 00:06:46,000 Speaker 1: The latent images need some processing in order to create 108 00:06:46,040 --> 00:06:48,800 Speaker 1: something that can be fed through a film projector. The 109 00:06:48,839 --> 00:06:52,040 Speaker 1: development process creates a negative image of the chemical record, 110 00:06:52,600 --> 00:06:55,720 Speaker 1: and that means that the darkest areas of the image 111 00:06:55,760 --> 00:06:58,840 Speaker 1: represent the spots where the film received the most light. 112 00:06:59,240 --> 00:07:02,480 Speaker 1: It's the opposite of what you would expect, right. Anything 113 00:07:02,520 --> 00:07:05,440 Speaker 1: that would be dark in a photograph will be light 114 00:07:05,520 --> 00:07:08,479 Speaker 1: on a negative and vice versa. This negative has to 115 00:07:08,520 --> 00:07:10,800 Speaker 1: be transferred onto another role of film to create a 116 00:07:10,840 --> 00:07:13,200 Speaker 1: positive image in a process that I'm also not going 117 00:07:13,240 --> 00:07:15,560 Speaker 1: to cover because we need some time for actual topic. Right. 118 00:07:16,160 --> 00:07:18,920 Speaker 1: So when we watch a film, we have the perception 119 00:07:19,040 --> 00:07:22,840 Speaker 1: that what we're viewing are moving objects up on a screen, 120 00:07:23,320 --> 00:07:26,680 Speaker 1: but that is an illusion. What we're really seeing with 121 00:07:26,800 --> 00:07:30,600 Speaker 1: true film is that it's a series of photographs. The 122 00:07:30,640 --> 00:07:33,480 Speaker 1: projector is playing those photographs at the same speed that 123 00:07:33,560 --> 00:07:36,240 Speaker 1: the film camera used to make them twenty four frames 124 00:07:36,280 --> 00:07:40,240 Speaker 1: per second usually. I mean, if you want to play 125 00:07:40,240 --> 00:07:42,600 Speaker 1: stuff in slow motion, then you would shoot a film 126 00:07:42,640 --> 00:07:45,480 Speaker 1: at a much higher frame rate, like forty eight frames 127 00:07:45,520 --> 00:07:48,240 Speaker 1: per second, but you would play it back at the 128 00:07:48,280 --> 00:07:51,440 Speaker 1: standard twenty four frames per second, and that would give 129 00:07:51,480 --> 00:07:55,760 Speaker 1: you the slow motion effect. And back in the old days, 130 00:07:56,160 --> 00:08:00,240 Speaker 1: cameras were hand cranked, so you would get kind end 131 00:08:00,240 --> 00:08:03,680 Speaker 1: of twenty four frames per second, but this would result 132 00:08:03,760 --> 00:08:06,520 Speaker 1: in sort of that hurky jerky movement we associate with 133 00:08:06,640 --> 00:08:12,200 Speaker 1: old movies that was hand cranked cinematography, and sometimes people 134 00:08:12,280 --> 00:08:15,400 Speaker 1: would turn the crank a little faster or a little 135 00:08:15,440 --> 00:08:18,440 Speaker 1: slower than others, so you don't really have a consistent 136 00:08:19,080 --> 00:08:22,160 Speaker 1: experience there, because the playback speed, especially if you're playing 137 00:08:22,160 --> 00:08:25,320 Speaker 1: it in a modern projector, is going to be standard, 138 00:08:25,360 --> 00:08:29,280 Speaker 1: even if the recording speed wasn't. But never mind all that. 139 00:08:29,360 --> 00:08:32,760 Speaker 1: If you were to stop the projector's reels at any 140 00:08:32,800 --> 00:08:35,480 Speaker 1: given moment in the playback of a film, you would 141 00:08:35,520 --> 00:08:38,920 Speaker 1: see a still image. You would advance the reel by 142 00:08:38,920 --> 00:08:41,520 Speaker 1: one frame, and you would see the next image, the 143 00:08:41,559 --> 00:08:44,880 Speaker 1: next photograph in that series, and you would likely be 144 00:08:44,920 --> 00:08:47,959 Speaker 1: able to pick out how things are slightly different from 145 00:08:48,080 --> 00:08:50,760 Speaker 1: the first frame you looked at and the next frame. 146 00:08:51,240 --> 00:08:53,920 Speaker 1: And this is the same principle that's behind animation. If 147 00:08:53,960 --> 00:08:56,200 Speaker 1: you've ever taken a pad of sticky notes and you 148 00:08:56,320 --> 00:08:59,679 Speaker 1: drawn little figures on page after page after page that 149 00:08:59,720 --> 00:09:02,560 Speaker 1: when you flip the pages, you get a simple little cartoon, 150 00:09:02,880 --> 00:09:06,360 Speaker 1: then you've engaged in the same art form as great cinematographers. 151 00:09:06,559 --> 00:09:08,640 Speaker 1: Then maybe your work was even better than theirs. I'm 152 00:09:08,640 --> 00:09:10,960 Speaker 1: not one to judge. Now, why would I go to 153 00:09:11,000 --> 00:09:13,439 Speaker 1: the trouble to cover the basics of film? Well, it's 154 00:09:13,480 --> 00:09:16,120 Speaker 1: because the very nature of film inspired certain people to 155 00:09:16,400 --> 00:09:19,800 Speaker 1: experiment with it, to try stuff that would be impossible 156 00:09:19,840 --> 00:09:22,600 Speaker 1: to replicate in a real world setting, or at least 157 00:09:22,840 --> 00:09:27,360 Speaker 1: it would be really difficult. Film wasn't a substitution for 158 00:09:27,400 --> 00:09:30,800 Speaker 1: a theater. In theater, you can create a few interesting effects. 159 00:09:31,080 --> 00:09:35,040 Speaker 1: Generally your options are limited to things like lighting tricks, 160 00:09:35,240 --> 00:09:39,080 Speaker 1: maybe some creative sets or costumes, maybe an even a 161 00:09:39,120 --> 00:09:42,400 Speaker 1: stage illusion or two, and perhaps some sound design. But 162 00:09:42,480 --> 00:09:46,200 Speaker 1: with film there were other possibilities, and one fellow who 163 00:09:46,240 --> 00:09:52,400 Speaker 1: recognized those possibilities was the French filmmaker and illusionist George Mellier. 164 00:09:53,000 --> 00:09:55,960 Speaker 1: He was born in Paris, You know Paris in eighteen 165 00:09:56,040 --> 00:09:59,319 Speaker 1: sixty one. Let that sink in for a moment. This 166 00:09:59,400 --> 00:10:03,000 Speaker 1: man was born while the Civil War was going on 167 00:10:03,120 --> 00:10:07,640 Speaker 1: in the United States. He became interested in stagecraft and magic, 168 00:10:07,720 --> 00:10:11,320 Speaker 1: and by the eighteen nineties he was a successful stage magician. 169 00:10:11,840 --> 00:10:14,880 Speaker 1: In eighteen ninety five, he saw an early film exhibition 170 00:10:14,960 --> 00:10:18,520 Speaker 1: made by the Lumier Brothers and he became entranced by 171 00:10:18,520 --> 00:10:22,160 Speaker 1: this new medium. His experience and illusions encouraged him to 172 00:10:22,160 --> 00:10:25,559 Speaker 1: find ways to experiment with film to achieve new effects, 173 00:10:25,800 --> 00:10:28,960 Speaker 1: stuff that wouldn't be possible to do in the real world. 174 00:10:29,559 --> 00:10:32,760 Speaker 1: He was a special effects and film pioneer. He established 175 00:10:32,800 --> 00:10:37,839 Speaker 1: methods to shoot slow motion, stop motion animation, to do dissolves, 176 00:10:37,880 --> 00:10:42,920 Speaker 1: and tricks like superimposition and double exposure. Around eighteen ninety eight, 177 00:10:43,200 --> 00:10:46,040 Speaker 1: Melier had a really cool idea. He wanted to create 178 00:10:46,080 --> 00:10:49,200 Speaker 1: a truly bizarre special effect in which an actor would 179 00:10:49,200 --> 00:10:53,520 Speaker 1: appear to remove his own head on screen. But how 180 00:10:53,520 --> 00:10:57,520 Speaker 1: would he accomplish this? While the secret was in shooting 181 00:10:57,600 --> 00:11:01,679 Speaker 1: multiple exposures of the same real film. Typically, after you 182 00:11:01,720 --> 00:11:04,400 Speaker 1: expose film to light, you want to avoid doing that 183 00:11:04,480 --> 00:11:07,920 Speaker 1: again because you will interfere with that chemical record. You know, 184 00:11:07,960 --> 00:11:10,680 Speaker 1: if you were to ever take photographs with a film 185 00:11:10,760 --> 00:11:13,960 Speaker 1: camera and then someone were to open up the back 186 00:11:14,000 --> 00:11:18,120 Speaker 1: of the camera and expose the film to regular light, 187 00:11:18,800 --> 00:11:21,880 Speaker 1: you could potentially ruin shots that were already made, plus 188 00:11:21,960 --> 00:11:24,840 Speaker 1: ruin the film for the next couple of shots. It's 189 00:11:24,920 --> 00:11:28,080 Speaker 1: not something that you typically want to do. More light 190 00:11:28,160 --> 00:11:32,640 Speaker 1: will cause further reactions, chemical reactions on the actual plastic film, 191 00:11:32,679 --> 00:11:35,800 Speaker 1: and your shot gets ruined. If you've ever used the 192 00:11:35,920 --> 00:11:39,040 Speaker 1: cameras that don't quite line up the film properly at 193 00:11:39,080 --> 00:11:41,160 Speaker 1: the very beginning or the very end, you might even 194 00:11:41,200 --> 00:11:44,800 Speaker 1: notice that a couple of photos on those sections of 195 00:11:44,880 --> 00:11:49,079 Speaker 1: the film role have two sets of images super imposed 196 00:11:49,120 --> 00:11:52,720 Speaker 1: on top of one another, and that's because that little 197 00:11:52,760 --> 00:11:56,440 Speaker 1: section of film was exposed more than once. Melia did 198 00:11:56,440 --> 00:12:00,120 Speaker 1: this on purpose. He would set up a shot and 199 00:12:00,160 --> 00:12:02,240 Speaker 1: he would use a lens that had some of the 200 00:12:02,360 --> 00:12:06,000 Speaker 1: lens blacked out so that light could not pass through 201 00:12:06,120 --> 00:12:08,720 Speaker 1: that part of the lens. And we refer to this 202 00:12:08,960 --> 00:12:12,960 Speaker 1: as a mat matte, and you can think of it 203 00:12:13,040 --> 00:12:15,960 Speaker 1: like a mask for the lens, and that would mean 204 00:12:16,000 --> 00:12:18,640 Speaker 1: a section of each frame corresponding to that part of 205 00:12:18,640 --> 00:12:21,480 Speaker 1: the mat would remain unexposed to light. He would shoot 206 00:12:21,520 --> 00:12:25,720 Speaker 1: the scene as rehearsed. Afterward, he would rewind the exposed 207 00:12:25,760 --> 00:12:27,880 Speaker 1: film in the camera, beat it right back in as 208 00:12:27,920 --> 00:12:29,880 Speaker 1: if he was going to shoot something all for the 209 00:12:29,920 --> 00:12:34,560 Speaker 1: first time, and he would then replace this mat with 210 00:12:34,640 --> 00:12:37,680 Speaker 1: a new one and the new mat would block out 211 00:12:37,920 --> 00:12:43,600 Speaker 1: everything except the section that previously was unexposed. So in 212 00:12:43,600 --> 00:12:46,559 Speaker 1: other words, the part that was black would now be clear, 213 00:12:46,920 --> 00:12:50,400 Speaker 1: and the rest of the lens that was previously unblacked 214 00:12:50,600 --> 00:12:53,200 Speaker 1: would be blacked. So you replace one mat with a 215 00:12:53,240 --> 00:12:56,520 Speaker 1: different one. So he would then be able to film 216 00:12:56,559 --> 00:12:58,960 Speaker 1: something totally new into this same role of film, and 217 00:12:59,000 --> 00:13:02,120 Speaker 1: this time the would pick up a new scene and 218 00:13:02,160 --> 00:13:04,440 Speaker 1: by changing things between one section and the other, he 219 00:13:04,440 --> 00:13:07,760 Speaker 1: could create weird effects like the head removal trick. It 220 00:13:07,760 --> 00:13:10,440 Speaker 1: would appear as though all of this was shot at 221 00:13:10,480 --> 00:13:12,880 Speaker 1: the same time on the same role of film, but 222 00:13:13,000 --> 00:13:15,960 Speaker 1: in fact, through careful control of where the light would go, 223 00:13:16,280 --> 00:13:20,880 Speaker 1: Melia would use the same film twice or more to 224 00:13:20,960 --> 00:13:23,360 Speaker 1: produce cool results. And if you want to see an 225 00:13:23,360 --> 00:13:26,840 Speaker 1: example of what I'm talking about, and I highly recommend 226 00:13:26,840 --> 00:13:29,320 Speaker 1: you check this out because it is amazing even today, 227 00:13:30,120 --> 00:13:32,960 Speaker 1: go to YouTube and do a search for the short 228 00:13:32,960 --> 00:13:37,480 Speaker 1: film four Heads Are Better than One. The creativity of 229 00:13:37,480 --> 00:13:40,800 Speaker 1: this film, which by the way, lasts less than a minute, 230 00:13:41,320 --> 00:13:45,800 Speaker 1: is still astonishing. To say his experimental work was influential 231 00:13:46,559 --> 00:13:50,200 Speaker 1: would be a gross understatement. Other filmmakers, inspired by the 232 00:13:50,200 --> 00:13:53,880 Speaker 1: work of Melia tried new techniques that built upon the 233 00:13:53,920 --> 00:13:59,280 Speaker 1: foundation he established. For example, filmmaker and documentarian Norman Dawn 234 00:13:59,440 --> 00:14:03,520 Speaker 1: wanted to show films at historic buildings around California, but 235 00:14:04,080 --> 00:14:08,120 Speaker 1: several of those buildings had been damaged or even partly destroyed. 236 00:14:08,720 --> 00:14:12,800 Speaker 1: Other historic buildings had modern stuff like light poles in 237 00:14:12,800 --> 00:14:14,760 Speaker 1: front of them. He didn't want that to be in 238 00:14:14,800 --> 00:14:17,480 Speaker 1: the shot, so he wanted to show the buildings as 239 00:14:17,520 --> 00:14:21,400 Speaker 1: they had appeared in their original form before the decay, 240 00:14:21,560 --> 00:14:26,400 Speaker 1: before modern technology had advanced into the area. So he 241 00:14:26,520 --> 00:14:30,600 Speaker 1: came up with a really clever idea. Dawn placed a 242 00:14:30,640 --> 00:14:34,040 Speaker 1: pane of glass between the camera and the scene he 243 00:14:34,160 --> 00:14:37,520 Speaker 1: wanted to shoot, and on that pane of glass he 244 00:14:37,600 --> 00:14:41,480 Speaker 1: had paintings to enhance the scene. If a building's roof 245 00:14:41,480 --> 00:14:43,760 Speaker 1: had caved in, he would frame up the shot and 246 00:14:43,760 --> 00:14:46,320 Speaker 1: then have an artist paint a roof on the glass 247 00:14:46,480 --> 00:14:49,480 Speaker 1: so that when viewed through the camera, the painting and 248 00:14:49,520 --> 00:14:52,440 Speaker 1: the building behind it would line up and the building 249 00:14:52,480 --> 00:14:55,040 Speaker 1: would appear to be whole again. Or he might want 250 00:14:55,080 --> 00:14:57,720 Speaker 1: to cover up stuff like those telephone poles. He would 251 00:14:57,760 --> 00:15:01,000 Speaker 1: have an artist paint trees on the so from the 252 00:15:01,000 --> 00:15:05,240 Speaker 1: camera's perspective the polls were hidden. His process also involved 253 00:15:05,360 --> 00:15:09,320 Speaker 1: double exposures. This was an example of a Matt painting, 254 00:15:09,760 --> 00:15:12,680 Speaker 1: and he would claim credit for inventing this, and he 255 00:15:12,760 --> 00:15:15,920 Speaker 1: even applied for a patent on it. But subsequent lawsuits 256 00:15:16,000 --> 00:15:19,160 Speaker 1: established that other filmmakers were using similar approaches, and the 257 00:15:19,200 --> 00:15:23,240 Speaker 1: patent office ultimately denied the claim, but Matt paintings would 258 00:15:23,240 --> 00:15:26,200 Speaker 1: become an important part of filmmaking from that point forward. 259 00:15:26,840 --> 00:15:30,960 Speaker 1: One disadvantage to these early film effects was they required 260 00:15:30,960 --> 00:15:34,040 Speaker 1: the camera to remain stationary through the whole process. You 261 00:15:34,080 --> 00:15:37,440 Speaker 1: couldn't move the camera at all, or else your shots 262 00:15:37,440 --> 00:15:40,320 Speaker 1: wouldn't line up, so you wanted the camera to remain 263 00:15:40,360 --> 00:15:43,760 Speaker 1: in one place through all of these different exposures. Another 264 00:15:43,800 --> 00:15:46,960 Speaker 1: problem was that no action could cross the Matt line 265 00:15:47,040 --> 00:15:49,720 Speaker 1: because it would get cut off as it moved beyond 266 00:15:50,200 --> 00:15:54,720 Speaker 1: that invisible at least from the audience's perspective line. Now, 267 00:15:54,800 --> 00:15:57,440 Speaker 1: let's move on up to nineteen eighteen, when a guy 268 00:15:57,520 --> 00:16:03,360 Speaker 1: named Frank Williams created the Williams process, which honestly seems 269 00:16:03,400 --> 00:16:07,520 Speaker 1: pretty convenient to me. The Williams process allowed for more 270 00:16:07,600 --> 00:16:11,440 Speaker 1: movement and involved shooting actors against a solid background such 271 00:16:11,480 --> 00:16:16,320 Speaker 1: as a black or blue curtain on very high contrast film. 272 00:16:16,720 --> 00:16:21,400 Speaker 1: The process sometimes required multiple transfers onto new film until 273 00:16:21,440 --> 00:16:25,800 Speaker 1: you arrived at a black silhouette against a pure white background, 274 00:16:25,880 --> 00:16:28,400 Speaker 1: the negative image of what you were shooting before, and 275 00:16:28,440 --> 00:16:31,120 Speaker 1: this was called a holdout matt. The way these transfers 276 00:16:31,160 --> 00:16:33,560 Speaker 1: typically would work is that you would put one strip 277 00:16:33,680 --> 00:16:37,600 Speaker 1: of shot developed film into a camera, so you've already 278 00:16:37,600 --> 00:16:39,520 Speaker 1: shot on it, but you're putting it through the camera again. 279 00:16:40,360 --> 00:16:44,800 Speaker 1: And you would put a second strip of film that 280 00:16:45,040 --> 00:16:49,480 Speaker 1: is unshot, it's unprocessed, no lights hit it, and put 281 00:16:49,520 --> 00:16:53,360 Speaker 1: it right up against the first developed piece of film. 282 00:16:53,600 --> 00:16:56,600 Speaker 1: You would shine light through the camera and you would 283 00:16:56,680 --> 00:17:00,000 Speaker 1: let it just run. And this way you would transfer 284 00:17:00,080 --> 00:17:04,000 Speaker 1: for the images from one strip to the other. And 285 00:17:04,480 --> 00:17:07,800 Speaker 1: this was called bypacking because you were putting two different 286 00:17:07,880 --> 00:17:11,960 Speaker 1: pieces of film through the camera to achieve this process. 287 00:17:12,400 --> 00:17:15,240 Speaker 1: And you could also do this not just with developed 288 00:17:15,240 --> 00:17:17,760 Speaker 1: film where you're making copies. You could do it with negatives. 289 00:17:17,760 --> 00:17:21,240 Speaker 1: You could do it in a way to increase contrast 290 00:17:21,359 --> 00:17:24,120 Speaker 1: from copy to copy until you were able to create 291 00:17:24,480 --> 00:17:28,680 Speaker 1: a holdout mat reverse printing. The holdout matt creates a 292 00:17:28,720 --> 00:17:32,920 Speaker 1: white silhouette on a black background or a cover mat. 293 00:17:33,000 --> 00:17:35,960 Speaker 1: So now you've got a holdout matt and a cover mat. 294 00:17:36,240 --> 00:17:39,040 Speaker 1: You would take the footage of a previously shot background. 295 00:17:39,119 --> 00:17:41,760 Speaker 1: Let's say it's a foreboding forest, so you've shot your 296 00:17:41,800 --> 00:17:44,640 Speaker 1: actors in a sound stage, but you want the background 297 00:17:44,640 --> 00:17:47,600 Speaker 1: to be this really scary looking forest, and you would 298 00:17:47,600 --> 00:17:51,000 Speaker 1: bypack a film camera with the background footage that you 299 00:17:51,040 --> 00:17:55,920 Speaker 1: had shot and the black silhouette holdout matt of the 300 00:17:56,200 --> 00:17:59,840 Speaker 1: actor's footage that you shot. Then you would transfer this 301 00:18:00,080 --> 00:18:04,440 Speaker 1: combination to a third piece of unexposed film by again 302 00:18:04,520 --> 00:18:07,360 Speaker 1: shining a light through those other two pieces. And because 303 00:18:07,400 --> 00:18:11,760 Speaker 1: the background on the holdout mat is white, the light 304 00:18:11,880 --> 00:18:14,560 Speaker 1: passes through it easily and it hits the previously shot 305 00:18:14,600 --> 00:18:17,720 Speaker 1: background image that comes through and gets copied onto the 306 00:18:17,720 --> 00:18:22,360 Speaker 1: blank film. The silhouette of your actors is black that 307 00:18:22,400 --> 00:18:26,760 Speaker 1: prevents light from passing through. So the previously blank third 308 00:18:26,800 --> 00:18:29,720 Speaker 1: piece of film now has a background image and this 309 00:18:29,880 --> 00:18:33,840 Speaker 1: dark silhouette of actors moving through the frame. Then you 310 00:18:33,840 --> 00:18:36,840 Speaker 1: would have to take that piece of film that has 311 00:18:36,880 --> 00:18:39,399 Speaker 1: this black silhouette and you have to bypack it with 312 00:18:39,440 --> 00:18:42,119 Speaker 1: the original footage of the actor, not the silhouette, but 313 00:18:42,160 --> 00:18:45,919 Speaker 1: the actual actor footage. And now the real actor is 314 00:18:46,000 --> 00:18:48,600 Speaker 1: on top of the silhouette and appears to actually be 315 00:18:48,840 --> 00:18:51,200 Speaker 1: in front of whatever the background image is, in our case, 316 00:18:51,240 --> 00:18:55,280 Speaker 1: the foreboding forest. Because this type of matt moves from 317 00:18:55,320 --> 00:18:59,000 Speaker 1: frame to frame, it's called a traveling mat. And if 318 00:18:59,040 --> 00:19:02,720 Speaker 1: you remember Fraggle Rock you might remember Traveling Matt is 319 00:19:02,760 --> 00:19:06,560 Speaker 1: the name of Gobo's uncle. Gobo, by the way, is 320 00:19:06,600 --> 00:19:09,600 Speaker 1: another stage and lighting term. It stands for a template 321 00:19:09,760 --> 00:19:12,960 Speaker 1: or stencil that controls the shape of a lamps emitted light. 322 00:19:13,800 --> 00:19:19,199 Speaker 1: So some of the Fraggles had fun industry names, Gobo 323 00:19:19,280 --> 00:19:22,600 Speaker 1: and traveling Matt. When we come back, we will continue 324 00:19:22,680 --> 00:19:26,320 Speaker 1: down the history of how chroma key came about. But 325 00:19:26,359 --> 00:19:37,600 Speaker 1: first let's take a quick break. Before the break, I 326 00:19:37,680 --> 00:19:41,479 Speaker 1: was talking about the Williams process, but C. Dodge Dunning 327 00:19:41,520 --> 00:19:45,280 Speaker 1: would improve upon the Williams process by using yellow light 328 00:19:45,359 --> 00:19:47,439 Speaker 1: to shoot the actor in front of a blue screen, 329 00:19:48,040 --> 00:19:52,000 Speaker 1: creating the Dunning process, and this was used extensively in 330 00:19:52,040 --> 00:19:55,560 Speaker 1: the classic nineteen thirty three film King Kong, and they 331 00:19:55,640 --> 00:19:57,879 Speaker 1: weren't great for black and white film. Remember this is 332 00:19:57,920 --> 00:20:01,840 Speaker 1: before anyone was shooting on color. So although I mean 333 00:20:01,880 --> 00:20:04,840 Speaker 1: there were ways of treating film to create color, but 334 00:20:04,920 --> 00:20:07,640 Speaker 1: this was standard black and white film, so you didn't 335 00:20:07,680 --> 00:20:10,800 Speaker 1: have to worry about the weird lighting. But if you 336 00:20:10,840 --> 00:20:12,920 Speaker 1: wanted to shoot in color, that was going to cause 337 00:20:13,359 --> 00:20:18,440 Speaker 1: or require other considerations. Around the same time, engineers were 338 00:20:18,480 --> 00:20:22,600 Speaker 1: developing the optical printer, which really simplified the process of 339 00:20:22,600 --> 00:20:25,719 Speaker 1: transferring images from one strip of film to another. Now 340 00:20:25,760 --> 00:20:30,879 Speaker 1: I talked about bypacking, but the optical process could be 341 00:20:31,240 --> 00:20:34,639 Speaker 1: an alternative to that. It didn't eliminate it, but it 342 00:20:34,720 --> 00:20:37,480 Speaker 1: was a different way to achieve the same thing. Essentially, 343 00:20:38,119 --> 00:20:42,000 Speaker 1: an optical printer has a projector on one side and 344 00:20:42,040 --> 00:20:45,119 Speaker 1: a camera on the other. The projector shoots out a 345 00:20:45,119 --> 00:20:48,400 Speaker 1: projected image that then gets copied onto a new, unexposed 346 00:20:48,480 --> 00:20:50,879 Speaker 1: role of film inside the camera. And it also allowed 347 00:20:50,880 --> 00:20:53,919 Speaker 1: filmmakers to create new effects by changing the focal point 348 00:20:54,160 --> 00:20:56,879 Speaker 1: of the camera or the distance between the projector and 349 00:20:56,920 --> 00:20:59,959 Speaker 1: the camera. And rather than bypacking camera, you just use 350 00:21:00,160 --> 00:21:03,720 Speaker 1: this process you could get better results. The first mass 351 00:21:03,720 --> 00:21:06,960 Speaker 1: produced optical printer hit the market in the mid nineteen forties. 352 00:21:07,200 --> 00:21:10,440 Speaker 1: It came from a company called Acme Donne. In addition, 353 00:21:10,600 --> 00:21:15,440 Speaker 1: filmmakers created rear projection backgrounds, so in these actors would 354 00:21:15,480 --> 00:21:19,320 Speaker 1: perform in front of a screen like a projection screen, 355 00:21:19,520 --> 00:21:23,119 Speaker 1: not a green screen or a blue screen, and behind 356 00:21:23,400 --> 00:21:26,640 Speaker 1: that screen would be a film projector and it would 357 00:21:26,640 --> 00:21:31,200 Speaker 1: provide a projected background image. You could do this in 358 00:21:31,240 --> 00:21:34,600 Speaker 1: place of the processes have already described, putting your actors 359 00:21:34,640 --> 00:21:37,320 Speaker 1: in front of a screen that shows whatever background you wanted. 360 00:21:37,680 --> 00:21:40,359 Speaker 1: The background could be fairly static, but didn't have to be. 361 00:21:40,800 --> 00:21:45,199 Speaker 1: You could include a background that was actually dynamic, showing movement. 362 00:21:45,359 --> 00:21:47,919 Speaker 1: It could be a film in of itself. This was 363 00:21:48,000 --> 00:21:50,919 Speaker 1: used a lot in shots where people were in vehicles 364 00:21:51,119 --> 00:21:54,040 Speaker 1: and talking with one another. So rather than setting up 365 00:21:54,119 --> 00:21:56,720 Speaker 1: a car on a trailer and shooting it in the 366 00:21:56,760 --> 00:21:59,400 Speaker 1: real world with the camera on the trailer, or worse yet, 367 00:21:59,400 --> 00:22:01,480 Speaker 1: trying to figure out how to fit a camera onto 368 00:22:01,520 --> 00:22:05,080 Speaker 1: a real moving car that's operated by an actor, you 369 00:22:05,080 --> 00:22:08,679 Speaker 1: would typically have performers sitting in a stationary vehicle and 370 00:22:08,760 --> 00:22:12,120 Speaker 1: the screen behind and sometimes to either side of them 371 00:22:12,480 --> 00:22:16,160 Speaker 1: would display previously shot footage of scenery going by from 372 00:22:16,200 --> 00:22:19,680 Speaker 1: the correct perspective, as if the car were driving down 373 00:22:19,720 --> 00:22:23,080 Speaker 1: the road. This wasn't necessarily convincing, mind you, but it 374 00:22:23,240 --> 00:22:27,399 Speaker 1: was an interesting technique. In nineteen thirty two, engineers created 375 00:22:27,440 --> 00:22:32,880 Speaker 1: a process to produce films in color called appropriately Technicolor. Interestingly, 376 00:22:33,200 --> 00:22:37,080 Speaker 1: in this process, images would be captured to three strips 377 00:22:37,200 --> 00:22:40,199 Speaker 1: of black and white film at this stage as the 378 00:22:40,440 --> 00:22:44,760 Speaker 1: tri strip approach. This was not the original version of Technicolor. 379 00:22:44,800 --> 00:22:49,119 Speaker 1: It was technically the fourth incarnation of the Technicolor technology, 380 00:22:49,119 --> 00:22:52,560 Speaker 1: but it's the important one for our discussion. So how 381 00:22:52,600 --> 00:22:56,159 Speaker 1: do you produce a color image if you're using black 382 00:22:56,200 --> 00:22:59,600 Speaker 1: and white film as your medium? Well, first you have 383 00:22:59,640 --> 00:23:03,840 Speaker 1: to shoot your footage. And inside an early Technicolor tri 384 00:23:04,040 --> 00:23:09,199 Speaker 1: strip camera behind the lens was an optical cube and 385 00:23:09,240 --> 00:23:12,920 Speaker 1: it acted as a prism. Prisms break up incoming light 386 00:23:13,040 --> 00:23:17,919 Speaker 1: into bands of frequencies, and you've likely had one, or 387 00:23:17,960 --> 00:23:20,440 Speaker 1: played with one, or at least seen one. That's the 388 00:23:20,520 --> 00:23:21,879 Speaker 1: kind of stuff, you know. A light goes through it 389 00:23:21,920 --> 00:23:24,000 Speaker 1: and then it makes rainbows. You see a little rainbow 390 00:23:24,040 --> 00:23:28,520 Speaker 1: pattern projected somewhere. This prism would break up the incoming 391 00:23:28,600 --> 00:23:32,199 Speaker 1: light into three general bands that corresponded with red, green, 392 00:23:32,320 --> 00:23:35,920 Speaker 1: and blue. Each of those bands of light would hit 393 00:23:36,040 --> 00:23:39,000 Speaker 1: one of three strips of black and white film inside 394 00:23:39,000 --> 00:23:42,080 Speaker 1: the camera, so one strip of film would be exposed 395 00:23:42,119 --> 00:23:44,880 Speaker 1: to all the red light coming from a scene, one 396 00:23:44,920 --> 00:23:47,080 Speaker 1: from all the green light coming from a scene and 397 00:23:47,160 --> 00:23:49,840 Speaker 1: one from the blue. The concentration of each color in 398 00:23:49,880 --> 00:23:52,680 Speaker 1: the scene would affect how much light was hitting each 399 00:23:52,800 --> 00:23:55,920 Speaker 1: strip of film, So you'd end up with three negatives 400 00:23:56,000 --> 00:24:00,439 Speaker 1: of your scene that were all perfectly synchronized, all of 401 00:24:00,480 --> 00:24:04,040 Speaker 1: them in black and white, but each with different levels 402 00:24:04,040 --> 00:24:07,520 Speaker 1: of brightness for different objects. It all depended on what 403 00:24:07,760 --> 00:24:10,879 Speaker 1: color the objects were in the scene. A red chair, 404 00:24:11,200 --> 00:24:14,439 Speaker 1: for example, would appear as a very prominent image on 405 00:24:14,480 --> 00:24:16,359 Speaker 1: the black and white film that was hit with the 406 00:24:16,480 --> 00:24:20,120 Speaker 1: red light, while it would be less noticeable in the 407 00:24:20,160 --> 00:24:24,320 Speaker 1: green and blue strips. Now you would develop the negatives, 408 00:24:24,359 --> 00:24:27,879 Speaker 1: and you would process the film, the three strips of film, 409 00:24:28,280 --> 00:24:30,080 Speaker 1: and you would print them just as you would a 410 00:24:30,119 --> 00:24:32,439 Speaker 1: regular black and white movie, and you would technically have 411 00:24:32,600 --> 00:24:36,960 Speaker 1: three identical black and white sequences that only well, not 412 00:24:37,040 --> 00:24:40,240 Speaker 1: identical because the brightness would be different between each, but 413 00:24:40,280 --> 00:24:44,040 Speaker 1: they would be of the exact same shot. You would 414 00:24:44,040 --> 00:24:48,000 Speaker 1: then process these film strips by dying each of them 415 00:24:48,040 --> 00:24:51,160 Speaker 1: in their respective color, so you would literally end up 416 00:24:51,200 --> 00:24:55,320 Speaker 1: with a red tinted strip of film, blue tinted strip 417 00:24:55,359 --> 00:24:59,040 Speaker 1: of film, and a green tinted strip of film. Then 418 00:24:59,080 --> 00:25:02,040 Speaker 1: you would take these three died strips of film, and 419 00:25:02,080 --> 00:25:04,560 Speaker 1: you would laminate them together and you would print that 420 00:25:04,720 --> 00:25:06,840 Speaker 1: to a new role of film and you would have 421 00:25:07,000 --> 00:25:12,280 Speaker 1: a color motion picture which was fairly accurate, although the 422 00:25:12,320 --> 00:25:15,560 Speaker 1: technical process would evolve over time to become even more so. 423 00:25:16,160 --> 00:25:18,679 Speaker 1: And the Technicolor process is really what set the stage 424 00:25:18,720 --> 00:25:21,320 Speaker 1: for the next part of our story. It's why I 425 00:25:21,440 --> 00:25:24,240 Speaker 1: felt the need to even explain how it worked. Now 426 00:25:24,280 --> 00:25:27,800 Speaker 1: we get to a guy named Lawrence Larry Butler. He 427 00:25:27,920 --> 00:25:30,040 Speaker 1: was born in nineteen oh eight and he was actually 428 00:25:30,080 --> 00:25:34,840 Speaker 1: a second generation optical effects professional. His father, William Butler, 429 00:25:35,080 --> 00:25:38,959 Speaker 1: had been a silent film actor who frequently appeared in d. W. 430 00:25:39,119 --> 00:25:42,760 Speaker 1: Griffith films. Larry worked on several motion pictures in the 431 00:25:42,840 --> 00:25:46,640 Speaker 1: nineteen thirties before creating a new compositing process in nineteen 432 00:25:46,760 --> 00:25:51,159 Speaker 1: forty for the film The Thief of Baghdad. In that film, 433 00:25:51,240 --> 00:25:54,680 Speaker 1: Butler introduced a new special effect approach and this would 434 00:25:54,720 --> 00:25:57,560 Speaker 1: be the birth of the blue screen. All right, So 435 00:25:57,640 --> 00:26:01,720 Speaker 1: let's break down this process, and it builds on Technicolor 436 00:26:01,880 --> 00:26:04,960 Speaker 1: as I mentioned. So with Technicolor, you get three prints 437 00:26:05,000 --> 00:26:07,760 Speaker 1: of your shot, right, one for red, one for green, 438 00:26:07,880 --> 00:26:11,199 Speaker 1: one for blue. If you created a solid backdrop in 439 00:26:11,320 --> 00:26:14,480 Speaker 1: one of those three colors and shot something in front 440 00:26:14,480 --> 00:26:17,800 Speaker 1: of that background. You could use that particular strip of 441 00:26:17,880 --> 00:26:22,320 Speaker 1: film to create a traveling mat. Remember, the color would 442 00:26:22,320 --> 00:26:25,280 Speaker 1: show up as very bright in your black and white 443 00:26:25,320 --> 00:26:28,160 Speaker 1: film print because a lot of light is reflecting off 444 00:26:28,280 --> 00:26:32,720 Speaker 1: of that particular color. Effectively, you could make a negative 445 00:26:32,840 --> 00:26:37,560 Speaker 1: image of whatever the foreground was. The stuff you're shooting 446 00:26:37,920 --> 00:26:41,320 Speaker 1: would be dark and the background would be bright. You 447 00:26:41,359 --> 00:26:43,600 Speaker 1: would have to make sure that nothing in the scene 448 00:26:43,760 --> 00:26:46,880 Speaker 1: had the same color, however, or else your traveling matt 449 00:26:46,920 --> 00:26:49,680 Speaker 1: would effectively have holes in it because the color of 450 00:26:49,720 --> 00:26:52,960 Speaker 1: the foreground would match the color of the background. You've 451 00:26:52,960 --> 00:26:55,920 Speaker 1: probably seen this if someone's ever worn a shirt that's 452 00:26:55,960 --> 00:26:58,480 Speaker 1: the same color as whatever screen they're supposed to be 453 00:26:58,520 --> 00:27:00,920 Speaker 1: standing in front of. The same thing would even happen 454 00:27:00,920 --> 00:27:05,040 Speaker 1: in film. It's just that it would happen well in 455 00:27:05,080 --> 00:27:07,639 Speaker 1: advance of anyone being able to see it happen, like 456 00:27:07,720 --> 00:27:09,280 Speaker 1: see the effect of it. Because you had to do 457 00:27:09,320 --> 00:27:12,080 Speaker 1: all this other processing. The other two strips of black 458 00:27:12,080 --> 00:27:15,320 Speaker 1: and white film would have pretty dark backgrounds because the 459 00:27:15,400 --> 00:27:18,800 Speaker 1: light projected onto them wouldn't match the color of the backdrop. Right, 460 00:27:19,960 --> 00:27:23,000 Speaker 1: And you could take the film of a background shot. 461 00:27:23,080 --> 00:27:26,000 Speaker 1: This is called the background plate. So this is previously 462 00:27:26,080 --> 00:27:29,200 Speaker 1: shot film of whatever it is, whatever setting you're planning 463 00:27:29,200 --> 00:27:31,960 Speaker 1: on putting this stuff, and then you use the traveling 464 00:27:32,000 --> 00:27:35,160 Speaker 1: mat against it in an optical printer, and that would 465 00:27:35,160 --> 00:27:39,400 Speaker 1: produce a silhouette of the foreground action. And it's that 466 00:27:39,520 --> 00:27:41,879 Speaker 1: black hole that's the shape of whatever it was you 467 00:27:41,920 --> 00:27:44,520 Speaker 1: were shooting. And you would take this new print in 468 00:27:44,560 --> 00:27:46,560 Speaker 1: which you've got the silhouette of your action, it's the 469 00:27:46,600 --> 00:27:50,200 Speaker 1: previously filmed backdrop, and combine that with the processed color 470 00:27:50,280 --> 00:27:53,600 Speaker 1: film to fill in that hole left by the traveling mat. 471 00:27:54,000 --> 00:27:57,360 Speaker 1: So you've got this possibility now of creating a traveling 472 00:27:57,400 --> 00:28:00,399 Speaker 1: mat by taking advantage of the technicolor process. But then 473 00:28:00,440 --> 00:28:02,679 Speaker 1: you have to make a decision which of the three 474 00:28:02,720 --> 00:28:06,639 Speaker 1: colors should be the focus. Whichever color you choose is 475 00:28:06,680 --> 00:28:10,040 Speaker 1: going to determine what you can shoot, because you can't 476 00:28:10,040 --> 00:28:12,560 Speaker 1: have any objects or people in the scene that have 477 00:28:13,080 --> 00:28:17,080 Speaker 1: that color on them, or the traveling matt won't work properly. 478 00:28:17,400 --> 00:28:20,040 Speaker 1: This is what I mean when I say, if you've 479 00:28:20,080 --> 00:28:23,240 Speaker 1: ever seen someone on screen who's had a background effect 480 00:28:23,320 --> 00:28:26,200 Speaker 1: bleed onto them because the color of clothing they're wearing, 481 00:28:26,680 --> 00:28:30,119 Speaker 1: what was letting it happen. You've seen that issue. So 482 00:28:30,200 --> 00:28:33,600 Speaker 1: Butler decided to go with blue as the backdrop color, 483 00:28:33,840 --> 00:28:36,680 Speaker 1: largely because he determined it was a color far removed 484 00:28:36,720 --> 00:28:39,920 Speaker 1: from skin tones, and he wanted to make sure that 485 00:28:40,000 --> 00:28:42,840 Speaker 1: actors wouldn't match the color of the background and mess 486 00:28:42,840 --> 00:28:45,400 Speaker 1: everything up. So as long as you weren't shooting anything 487 00:28:45,440 --> 00:28:48,000 Speaker 1: blue in the foreground, you could use this process to 488 00:28:48,000 --> 00:28:51,840 Speaker 1: make a composite image of the foreground action against a 489 00:28:51,960 --> 00:28:55,520 Speaker 1: different background. He also would combine the blue negative image 490 00:28:55,760 --> 00:28:59,280 Speaker 1: with the green positive or processed image to create a 491 00:28:59,360 --> 00:29:02,960 Speaker 1: better tracking matt, something a more solid silhouette. In other words, 492 00:29:03,400 --> 00:29:06,800 Speaker 1: Butler's contribution led to him winning an Academy Award for 493 00:29:06,880 --> 00:29:12,120 Speaker 1: this process. Still, this was an incredibly time consuming approach. 494 00:29:12,600 --> 00:29:15,720 Speaker 1: I'm sure you gathered that just from my explanation of it. 495 00:29:15,760 --> 00:29:17,960 Speaker 1: Because you had to shoot your sequence, you had to 496 00:29:18,000 --> 00:29:21,040 Speaker 1: create the traveling matte negative, you had to combine that 497 00:29:21,160 --> 00:29:23,920 Speaker 1: against the background footage, and you had to combine that 498 00:29:24,280 --> 00:29:27,000 Speaker 1: combination of the background image and the traveling matt with 499 00:29:27,120 --> 00:29:31,040 Speaker 1: the fully processed color image and then ultimately come up 500 00:29:31,120 --> 00:29:37,920 Speaker 1: with a composite piece of film. It gave filmmakers way 501 00:29:37,960 --> 00:29:40,760 Speaker 1: more options when making movies. It allowed them to shoot 502 00:29:40,800 --> 00:29:44,479 Speaker 1: stuff inside a sound stage rather than whatever location they 503 00:29:44,480 --> 00:29:46,320 Speaker 1: would have to go to, and it even opened up 504 00:29:46,360 --> 00:29:49,520 Speaker 1: locations that would otherwise be impossible. But it did require 505 00:29:49,600 --> 00:29:53,960 Speaker 1: a lot of post production time and work. It also 506 00:29:54,040 --> 00:29:57,000 Speaker 1: required a close attention to lighting, otherwise you would end 507 00:29:57,080 --> 00:29:59,800 Speaker 1: up with blue halos around people and that was pretty 508 00:30:00,040 --> 00:30:03,080 Speaker 1: aren't distracting. In fact, all of these different approaches required 509 00:30:03,800 --> 00:30:07,880 Speaker 1: really good lighting, sometimes really intense lighting, so it would 510 00:30:07,880 --> 00:30:11,520 Speaker 1: also create pretty uncomfortable shooting conditions. It would get really 511 00:30:11,600 --> 00:30:15,520 Speaker 1: hot in those sound stages. So while it was phenomenal technology, 512 00:30:15,520 --> 00:30:17,840 Speaker 1: it required a lot of finesse to use it properly, 513 00:30:18,160 --> 00:30:21,480 Speaker 1: and a human touch was absolutely necessary through every stage 514 00:30:21,520 --> 00:30:25,840 Speaker 1: of the process. Now, over the next several years, really decades, 515 00:30:26,280 --> 00:30:30,280 Speaker 1: movies benefited from this technology. The tech allowed filmmakers to 516 00:30:30,320 --> 00:30:33,120 Speaker 1: do all sorts of neat things. Not only could they 517 00:30:33,120 --> 00:30:35,440 Speaker 1: make it seem like actors were in places that would 518 00:30:35,440 --> 00:30:38,280 Speaker 1: be hard or difficult to shoot in or places that 519 00:30:38,320 --> 00:30:42,000 Speaker 1: maybe don't even exist, they also allowed for stuff like 520 00:30:42,040 --> 00:30:45,600 Speaker 1: the incorporation of animation and live action in a way 521 00:30:45,840 --> 00:30:49,640 Speaker 1: that wasn't really possible. Before I'll get back to that again, 522 00:30:49,720 --> 00:30:53,520 Speaker 1: in a second. But in the early nineteen fifties, Eastman 523 00:30:53,600 --> 00:30:57,280 Speaker 1: Kodak created the color motion picture film that simplified the 524 00:30:57,320 --> 00:31:01,520 Speaker 1: process of shooting on color significant So, rather than exposing 525 00:31:01,560 --> 00:31:04,200 Speaker 1: three strips of black and white film to different bands 526 00:31:04,240 --> 00:31:07,520 Speaker 1: of light and then processing them to create a composite 527 00:31:07,680 --> 00:31:11,440 Speaker 1: color image, this new film actually contained all the layers 528 00:31:11,480 --> 00:31:14,480 Speaker 1: that corresponded to blue, green, and red. They each had 529 00:31:14,960 --> 00:31:19,840 Speaker 1: essentially filters and dyes in them, and each layer effectively 530 00:31:19,880 --> 00:31:22,400 Speaker 1: had its own silver halide crystals and respective dyes, and 531 00:31:22,440 --> 00:31:25,720 Speaker 1: streamlining the process for shooting on and developing color film. 532 00:31:26,160 --> 00:31:28,200 Speaker 1: You just had to have one strip, not the tri 533 00:31:28,320 --> 00:31:32,840 Speaker 1: strip approach of Technicolor. It really changed things. Also, by 534 00:31:32,880 --> 00:31:35,560 Speaker 1: tweaking the blue screen process, some inventors were able to 535 00:31:35,560 --> 00:31:37,960 Speaker 1: get spectacular results. This gets us back to that live 536 00:31:38,000 --> 00:31:42,920 Speaker 1: action and animation discussion. That would be Petro Vlajos, who 537 00:31:42,960 --> 00:31:45,360 Speaker 1: was the engineer who worked on a little film called 538 00:31:45,440 --> 00:31:49,719 Speaker 1: Mary Poppins in the early nineteen sixties. Vlahos wanted to 539 00:31:49,760 --> 00:31:52,760 Speaker 1: improve upon the technology that Butler had created, and one 540 00:31:52,760 --> 00:31:55,120 Speaker 1: of the issues he sought to address was that the 541 00:31:55,120 --> 00:31:59,080 Speaker 1: color blue used for blue screens wasn't a specific wavelength 542 00:31:59,320 --> 00:32:02,640 Speaker 1: of light. You got to remember that the wavelength of light, 543 00:32:02,800 --> 00:32:05,320 Speaker 1: or if you prefer the frequency of light, the two 544 00:32:05,400 --> 00:32:10,000 Speaker 1: are related, determines the light's color, the color that we perceive, 545 00:32:10,480 --> 00:32:12,680 Speaker 1: and the wavelengths corresponding to The blue screens of the 546 00:32:12,720 --> 00:32:15,840 Speaker 1: day ranged from four hundred and thirty five nanometers to 547 00:32:15,960 --> 00:32:20,040 Speaker 1: five hundred nanometers, and that meant any color blue that 548 00:32:20,080 --> 00:32:22,840 Speaker 1: fell in or near that range was off limits for 549 00:32:22,960 --> 00:32:25,760 Speaker 1: use in a scene. Vlajos figured there had to be 550 00:32:25,840 --> 00:32:27,920 Speaker 1: a better way, and he decided to use a different 551 00:32:28,040 --> 00:32:32,720 Speaker 1: backdrop color entirely yellow, but not just any yellow. He 552 00:32:32,760 --> 00:32:36,600 Speaker 1: wanted a precise yellow, the yellow that comes from sodium 553 00:32:36,720 --> 00:32:41,200 Speaker 1: gas discharge lamps. When you excite sodium gas, essentially when 554 00:32:41,200 --> 00:32:44,160 Speaker 1: you energize it with electricity, the gas gives off a 555 00:32:44,240 --> 00:32:47,240 Speaker 1: distinct yellow light with a wavelength of five hundred eighty 556 00:32:47,280 --> 00:32:50,640 Speaker 1: nine nanometers. As long as nothing in the camera frame 557 00:32:50,800 --> 00:32:53,920 Speaker 1: matches that precise shade of yellow, you could have all 558 00:32:53,960 --> 00:32:57,760 Speaker 1: sorts of colors in the shot, including different shades of yellow, 559 00:32:58,120 --> 00:33:01,000 Speaker 1: and not have to worry about skimping on things like 560 00:33:01,320 --> 00:33:05,160 Speaker 1: blue costume pieces. Paired with this was a customized camera 561 00:33:05,240 --> 00:33:08,200 Speaker 1: that contained a prism that could isolate the five hundred 562 00:33:08,200 --> 00:33:11,200 Speaker 1: and eighty nine wavelength of light. Vlahos was able to 563 00:33:11,200 --> 00:33:15,040 Speaker 1: produce an incredibly precise and accurate traveling matt this way, 564 00:33:15,400 --> 00:33:18,760 Speaker 1: which meant Disney could place actors on any separate background 565 00:33:18,800 --> 00:33:21,760 Speaker 1: without worrying about the effect showing at the seams. In fact, 566 00:33:22,200 --> 00:33:24,480 Speaker 1: in one sequence, Mary Poppins is wearing a hat that 567 00:33:24,520 --> 00:33:27,560 Speaker 1: has this veil like material on it, and you can 568 00:33:27,600 --> 00:33:31,360 Speaker 1: actually see the background, the anime background, through the veil, 569 00:33:31,480 --> 00:33:35,160 Speaker 1: and that's because of the precision of this approach. There 570 00:33:35,240 --> 00:33:38,280 Speaker 1: was one small hiccup, which was that Vlahos only had 571 00:33:38,360 --> 00:33:43,280 Speaker 1: one working prism that could isolate this specific band of light, 572 00:33:43,320 --> 00:33:46,280 Speaker 1: this five hundred and eighty nine nanometer band of light, 573 00:33:46,760 --> 00:33:51,200 Speaker 1: so they only had one sodium vapor camera as a result. Now, 574 00:33:51,240 --> 00:33:54,240 Speaker 1: when we come back, we're going to look at the 575 00:33:54,280 --> 00:33:58,360 Speaker 1: further evolution of this technology, including how it has changed 576 00:33:58,440 --> 00:34:01,520 Speaker 1: once the digital realm because came a reality. But first 577 00:34:01,600 --> 00:34:13,240 Speaker 1: let's take another quick break. I've stuck with the film 578 00:34:13,280 --> 00:34:15,560 Speaker 1: world for this podcast so far, but i also have 579 00:34:15,600 --> 00:34:18,440 Speaker 1: to talk about the use of chroma key technology in 580 00:34:18,520 --> 00:34:21,279 Speaker 1: the world of live television. See Mary Poppins came out 581 00:34:21,280 --> 00:34:23,760 Speaker 1: in nineteen sixty four, but the first use of chroma 582 00:34:23,840 --> 00:34:26,840 Speaker 1: key on live TV was in the late nineteen fifties. 583 00:34:27,320 --> 00:34:30,480 Speaker 1: This is the same technology that would become the basis 584 00:34:30,520 --> 00:34:34,439 Speaker 1: for TV weather reports, where the meteorologist stands in front 585 00:34:34,480 --> 00:34:37,720 Speaker 1: of a wall which seems to have a dynamic map 586 00:34:37,760 --> 00:34:40,400 Speaker 1: on it that can change from one image to the next. 587 00:34:40,800 --> 00:34:44,160 Speaker 1: But if the process I've described required so many steps, 588 00:34:44,200 --> 00:34:47,000 Speaker 1: if you had to do so much post production on 589 00:34:47,040 --> 00:34:49,840 Speaker 1: the film, how could you take that same basic idea 590 00:34:49,920 --> 00:34:52,480 Speaker 1: and make it work in the realm of television, in 591 00:34:52,600 --> 00:34:57,279 Speaker 1: real time live broadcast. Frank Gaskins and Mitt Altman led 592 00:34:57,360 --> 00:35:00,840 Speaker 1: this effort at NBC in the nineteen fifties. They created 593 00:35:00,880 --> 00:35:04,200 Speaker 1: a television camera approach to chroma key and tested it 594 00:35:04,239 --> 00:35:07,400 Speaker 1: out in nineteen fifty seven with a live broadcast of 595 00:35:07,480 --> 00:35:11,680 Speaker 1: Matinee Theater. The specific story they chose to serve as 596 00:35:11,719 --> 00:35:16,120 Speaker 1: the first experiment here was an adaptation of The Invisible Man, 597 00:35:16,360 --> 00:35:19,400 Speaker 1: and that was fitting because the nineteen thirty three film 598 00:35:19,440 --> 00:35:22,120 Speaker 1: adaptation of The Invisible Man had relied heavily on the 599 00:35:22,160 --> 00:35:27,560 Speaker 1: old Williams process. The live television version initially relied on 600 00:35:27,680 --> 00:35:32,560 Speaker 1: two cameras. One camera would capture a background image, the 601 00:35:32,640 --> 00:35:35,359 Speaker 1: other camera would be the four ground camera that would 602 00:35:35,360 --> 00:35:38,440 Speaker 1: be for all the action in the sequence, and behind 603 00:35:38,520 --> 00:35:41,839 Speaker 1: all this action would be a blue backdrop. Combining these 604 00:35:41,840 --> 00:35:45,160 Speaker 1: two sets of images simultaneously in a device called a 605 00:35:45,280 --> 00:35:50,360 Speaker 1: chroma key amplifier would create a live composite video. Feed. 606 00:35:51,000 --> 00:35:53,880 Speaker 1: Engineers at RCA created the actual technology, and I think 607 00:35:53,920 --> 00:35:56,880 Speaker 1: it's best if I just quote directly from the nineteen 608 00:35:56,960 --> 00:36:01,440 Speaker 1: fifty eight edition of the journal Electronic Ada that describes 609 00:36:01,520 --> 00:36:04,920 Speaker 1: this process. So here's a quote. A switching signal or 610 00:36:04,920 --> 00:36:09,000 Speaker 1: a color key used in association with the special effects amplifier, 611 00:36:09,120 --> 00:36:12,480 Speaker 1: controls the signals sent out over the air. The switching 612 00:36:12,520 --> 00:36:16,080 Speaker 1: signal is in turn created by the camera photographing the 613 00:36:16,160 --> 00:36:19,360 Speaker 1: live action in front of the blue screen. While the 614 00:36:19,400 --> 00:36:23,480 Speaker 1: camera is scanning the blue screen, the switching device automatically 615 00:36:23,520 --> 00:36:27,480 Speaker 1: activates the second camera, which projects the background. When the 616 00:36:27,520 --> 00:36:30,680 Speaker 1: scanning signal reaches an area covered by the live actors, 617 00:36:31,000 --> 00:36:34,120 Speaker 1: the switching device turns off the camera projecting the background 618 00:36:34,200 --> 00:36:38,520 Speaker 1: material and transmits the action. Now that's the end of 619 00:36:38,560 --> 00:36:41,320 Speaker 1: that quote. You could also feed images directly to the 620 00:36:41,400 --> 00:36:43,880 Speaker 1: chroma key amplifier. It didn't have to be a live 621 00:36:44,080 --> 00:36:47,279 Speaker 1: video from a second camera, so you could provide an 622 00:36:47,280 --> 00:36:50,279 Speaker 1: image like a map, allowing a meteorologist to stand in 623 00:36:50,280 --> 00:36:53,520 Speaker 1: front of it otherwise blank blue or green screen and 624 00:36:53,600 --> 00:36:56,719 Speaker 1: gesture at various regions. The audience at home would see 625 00:36:56,760 --> 00:36:59,120 Speaker 1: the meteorologist appearing to stand in front of the map, 626 00:36:59,520 --> 00:37:01,759 Speaker 1: or may be a summary of the forecasted whether for 627 00:37:01,800 --> 00:37:04,560 Speaker 1: the week, and not just a blue screen or a 628 00:37:04,600 --> 00:37:08,279 Speaker 1: green screen. Around the nineteen seventies, that's when we started 629 00:37:08,320 --> 00:37:12,240 Speaker 1: to see a gradual shift, particularly in television, from blue 630 00:37:12,280 --> 00:37:16,320 Speaker 1: screens to green ones. Part of that was because of 631 00:37:16,360 --> 00:37:19,279 Speaker 1: a very slow transition into digital technology. It would become 632 00:37:19,280 --> 00:37:23,200 Speaker 1: more important as digital cameras became a thing. Digital cameras 633 00:37:23,239 --> 00:37:27,160 Speaker 1: were better attuned to doing this with greens rather than 634 00:37:27,200 --> 00:37:30,640 Speaker 1: with blues, although you can do either. But another big 635 00:37:30,680 --> 00:37:33,799 Speaker 1: reason was just that people don't tend to wear a 636 00:37:33,800 --> 00:37:36,960 Speaker 1: lot of green, whereas blue was a pretty and still 637 00:37:37,040 --> 00:37:39,480 Speaker 1: is a pretty popular color. And once in a while 638 00:37:39,640 --> 00:37:42,440 Speaker 1: someone on camera would forget that they're wearing blue, and 639 00:37:42,480 --> 00:37:44,560 Speaker 1: then they'd step in front of a blue screen and 640 00:37:44,680 --> 00:37:47,600 Speaker 1: suddenly their jacket or their shirt or their tie or 641 00:37:47,640 --> 00:37:51,360 Speaker 1: whatever would become part of the background image. Back to 642 00:37:51,480 --> 00:37:54,840 Speaker 1: film for a moment, we're gonna leave TV for a second. 643 00:37:55,400 --> 00:37:59,120 Speaker 1: In nineteen eighty a guy named Richard Edlund, who worked 644 00:37:59,160 --> 00:38:02,120 Speaker 1: on a little film called The Umpire Strikes Back, made 645 00:38:02,160 --> 00:38:06,200 Speaker 1: another big contribution to the chroma key process Edluin developed 646 00:38:06,239 --> 00:38:10,480 Speaker 1: a quad optical printer which both sped up the process 647 00:38:10,480 --> 00:38:14,200 Speaker 1: for producing composite film shots and also brought the price 648 00:38:14,360 --> 00:38:16,800 Speaker 1: down as well. I mean, if you think about it, 649 00:38:16,880 --> 00:38:21,920 Speaker 1: saving time means saving money. He also developed a computer 650 00:38:22,040 --> 00:38:26,280 Speaker 1: controlled system of cameras which allowed for very precise camera movements, 651 00:38:26,320 --> 00:38:29,759 Speaker 1: and that meant you could create choreographed shots of foreground 652 00:38:29,880 --> 00:38:33,520 Speaker 1: and background and composite them together and have them match 653 00:38:33,600 --> 00:38:37,280 Speaker 1: up perfectly. It was also really effective for processing images 654 00:38:37,360 --> 00:38:40,600 Speaker 1: that were shot with miniatures, which was done a lot 655 00:38:40,680 --> 00:38:43,479 Speaker 1: in the original Star Wars series. So it was still 656 00:38:43,480 --> 00:38:46,560 Speaker 1: a painstaking process, but now a lot more could be 657 00:38:46,640 --> 00:38:50,320 Speaker 1: done on one piece of equipment per pass, as opposed 658 00:38:50,360 --> 00:38:52,960 Speaker 1: to having to do a process on a piece of equipment, 659 00:38:53,600 --> 00:38:56,080 Speaker 1: then do it again and then again and again until 660 00:38:56,080 --> 00:39:00,760 Speaker 1: you finally got whatever result you were after. Gradually, software 661 00:39:00,800 --> 00:39:03,840 Speaker 1: would creep into the realm of film and video effects, 662 00:39:03,880 --> 00:39:06,160 Speaker 1: and this leads us to a version of chroma key 663 00:39:06,200 --> 00:39:09,760 Speaker 1: that I think is actually the easiest to understand. It's 664 00:39:09,920 --> 00:39:14,960 Speaker 1: technically advanced, but the principle is simple. So let's say 665 00:39:15,200 --> 00:39:17,719 Speaker 1: that you want to do a Twitch stream and you're 666 00:39:17,719 --> 00:39:20,280 Speaker 1: playing a video game live, and you want your viewers 667 00:39:20,600 --> 00:39:24,759 Speaker 1: to see you sitting in front of the video game footage. 668 00:39:24,920 --> 00:39:28,920 Speaker 1: So once to make a dynamic background, a video gameplay 669 00:39:29,000 --> 00:39:30,880 Speaker 1: behind you. So you go out and you buy a 670 00:39:30,920 --> 00:39:34,239 Speaker 1: green screen and you set it up behind your gaming chair. 671 00:39:34,320 --> 00:39:36,880 Speaker 1: You throw up some lights more on that in the second, 672 00:39:37,360 --> 00:39:40,120 Speaker 1: and you launch a program that will insert your video 673 00:39:40,160 --> 00:39:45,319 Speaker 1: game capture as a custom digital background. Your viewers will 674 00:39:45,320 --> 00:39:47,600 Speaker 1: see you sitting in front of a screen otherwise filled 675 00:39:47,600 --> 00:39:51,120 Speaker 1: with I don't know, Skyrim or Minecraft or the untitled 676 00:39:51,120 --> 00:39:54,479 Speaker 1: Goose game or whatever it is you're playing. What's going 677 00:39:54,520 --> 00:39:58,440 Speaker 1: on on a technical level, Well, the digital world is 678 00:39:58,560 --> 00:40:02,080 Speaker 1: different from the analog world in lots of ways, but 679 00:40:02,800 --> 00:40:05,480 Speaker 1: importantly for our discussion, it comes down to how in 680 00:40:05,480 --> 00:40:11,000 Speaker 1: the digital world everything ultimately boils down to numeric values. 681 00:40:11,719 --> 00:40:14,840 Speaker 1: You or I could have a debate about whether a 682 00:40:14,960 --> 00:40:20,200 Speaker 1: particular color is aquamarine versus arrow blue, versus blue green 683 00:40:20,440 --> 00:40:23,680 Speaker 1: versus dark cyan, or whatever it may be. But in 684 00:40:23,719 --> 00:40:28,240 Speaker 1: the digital world, every color ultimately has a numeric value. 685 00:40:29,000 --> 00:40:33,400 Speaker 1: Assuming whatever we're looking at is a solid color, you 686 00:40:33,440 --> 00:40:36,960 Speaker 1: could designate that solid color with a specific numeric value 687 00:40:36,960 --> 00:40:41,239 Speaker 1: in computer software and then replicate it or immediately identify 688 00:40:41,280 --> 00:40:44,759 Speaker 1: it within any scene you might see where I'm going here. 689 00:40:45,320 --> 00:40:48,879 Speaker 1: With video software, you can designate a specific color from 690 00:40:48,920 --> 00:40:54,240 Speaker 1: one video source. This specific color is the chroma, as 691 00:40:54,400 --> 00:40:57,319 Speaker 1: it were, and this is the color you want to 692 00:40:57,440 --> 00:41:02,959 Speaker 1: replace or key Outdo software analyzes information that's coming from 693 00:41:03,160 --> 00:41:06,400 Speaker 1: say a digital camera feed into your computer, and it 694 00:41:06,480 --> 00:41:09,680 Speaker 1: looks for any signals that map to the value or 695 00:41:09,880 --> 00:41:14,240 Speaker 1: values of the color or colors you've picked. Most software 696 00:41:14,320 --> 00:41:16,640 Speaker 1: lets you fine tune this, so you can adjust the 697 00:41:16,680 --> 00:41:20,000 Speaker 1: settings to hone in on the specific shade of green 698 00:41:20,160 --> 00:41:22,160 Speaker 1: or blue or whatever it is that you plan to 699 00:41:22,239 --> 00:41:26,080 Speaker 1: key out. Anything that matches that value or range of 700 00:41:26,160 --> 00:41:31,719 Speaker 1: values then gets turned into a transparent video layer. The 701 00:41:31,800 --> 00:41:36,160 Speaker 1: secondary image in our case, the video game footage that 702 00:41:36,200 --> 00:41:40,080 Speaker 1: we're creating as we're playing this game shows through this 703 00:41:40,160 --> 00:41:43,080 Speaker 1: transparent layer, and you can actually think of the foreground 704 00:41:43,200 --> 00:41:47,520 Speaker 1: video as an overlay on top of the digital background 705 00:41:47,600 --> 00:41:52,839 Speaker 1: layer the video game footage. Anything transparent in that overlay 706 00:41:53,320 --> 00:41:58,360 Speaker 1: will show the background through the solid stuff presumably you, 707 00:41:58,480 --> 00:42:03,200 Speaker 1: the Twitch player will block the background image so viewers 708 00:42:03,520 --> 00:42:06,000 Speaker 1: will be able to see their favorite Twitch streamer sitting 709 00:42:06,040 --> 00:42:08,880 Speaker 1: in front of a video game. The software does all 710 00:42:08,920 --> 00:42:11,600 Speaker 1: the work for you, creating the composite video feed that 711 00:42:11,640 --> 00:42:15,720 Speaker 1: the viewer sees. That software, by the way, isn't Twitch itself. 712 00:42:15,760 --> 00:42:19,200 Speaker 1: Twitch is a video streaming platform, but to actually do 713 00:42:19,360 --> 00:42:21,640 Speaker 1: these sort of effects, you'd need to use some other 714 00:42:21,680 --> 00:42:24,960 Speaker 1: piece of software, such as some version of open broadcaster 715 00:42:25,200 --> 00:42:27,960 Speaker 1: software or OBS. And there are a lot of different 716 00:42:28,080 --> 00:42:31,520 Speaker 1: versions of video broadcasting software available for folks to play with, 717 00:42:32,040 --> 00:42:36,040 Speaker 1: from free stuff to professional grade stuff. This type of 718 00:42:36,120 --> 00:42:38,319 Speaker 1: versatility is the kind of stuff that previously you would 719 00:42:38,320 --> 00:42:40,760 Speaker 1: have had to have worked in like a TV studio 720 00:42:40,920 --> 00:42:44,080 Speaker 1: to have access to, but now anyone with a sufficiently 721 00:42:44,160 --> 00:42:47,319 Speaker 1: beefy computer can run this kind of operation. For this 722 00:42:47,440 --> 00:42:50,840 Speaker 1: to work well, you'd want to have really good lighting, 723 00:42:51,000 --> 00:42:54,560 Speaker 1: both for the foreground and for the background drop. You 724 00:42:54,640 --> 00:42:56,960 Speaker 1: want the lighting on the green screen you're using to 725 00:42:57,000 --> 00:42:59,719 Speaker 1: be nice and even, and you want to eliminate any 726 00:42:59,800 --> 00:43:03,080 Speaker 1: chef because if you're casting a shadow on the green screen, 727 00:43:03,600 --> 00:43:07,200 Speaker 1: the camera will pick up that part of the green 728 00:43:07,239 --> 00:43:10,520 Speaker 1: screen as being a darker color and it might even 729 00:43:10,560 --> 00:43:13,759 Speaker 1: be dark enough that the video software doesn't identify it 730 00:43:13,880 --> 00:43:16,719 Speaker 1: as the color that you want to key out, So 731 00:43:16,880 --> 00:43:19,320 Speaker 1: in those cases you would get these weird video artifacts 732 00:43:19,400 --> 00:43:21,759 Speaker 1: on screen. As a result, it'd be really distracting. So 733 00:43:21,800 --> 00:43:26,080 Speaker 1: ideally you want lights that illuminate the green screen evenly 734 00:43:26,280 --> 00:43:29,480 Speaker 1: and are dedicated just for that purpose. If you're lighting 735 00:43:29,480 --> 00:43:32,239 Speaker 1: yourself directly from the front, you're not using a ring 736 00:43:32,320 --> 00:43:33,920 Speaker 1: light or anything like that, then you're going to be 737 00:43:33,960 --> 00:43:37,640 Speaker 1: casting a shadow behind you, unless your Peter Pan, in 738 00:43:37,640 --> 00:43:41,360 Speaker 1: which case I guess you just think happy thoughts. Now, 739 00:43:42,120 --> 00:43:45,800 Speaker 1: this flies for stuff like Zoom meetings and Twitch streams, 740 00:43:46,040 --> 00:43:49,359 Speaker 1: but when it comes to professional grade film, it's not 741 00:43:49,440 --> 00:43:52,719 Speaker 1: really up to snuff. Software can do a bulk of 742 00:43:52,760 --> 00:43:55,399 Speaker 1: the work, but good old human effects artists are still 743 00:43:55,400 --> 00:43:57,799 Speaker 1: needed to make sure everything is coming out well. They 744 00:43:57,880 --> 00:44:00,840 Speaker 1: can step in and do some quality control, can tweak 745 00:44:00,920 --> 00:44:03,799 Speaker 1: things that can fix any issues that pop up, and 746 00:44:03,840 --> 00:44:07,080 Speaker 1: that pays off. You've probably seen a movie that had 747 00:44:07,200 --> 00:44:10,720 Speaker 1: phenomenal attention to this process and the effects are top notch, 748 00:44:11,280 --> 00:44:14,200 Speaker 1: and you've probably seen other movies where, due to whatever reason, 749 00:44:14,360 --> 00:44:16,640 Speaker 1: maybe it was budget, maybe it was just the talent 750 00:44:16,680 --> 00:44:18,960 Speaker 1: of the people working on it, you could tell that 751 00:44:19,000 --> 00:44:22,520 Speaker 1: such care wasn't given to the process, and it shows 752 00:44:22,560 --> 00:44:25,840 Speaker 1: in the final product. I still think films like Jurassic 753 00:44:25,880 --> 00:44:29,120 Speaker 1: Park I'm talking about the original Jurassic Park hold up 754 00:44:29,320 --> 00:44:32,080 Speaker 1: pretty darn well. And part of that is that the 755 00:44:32,080 --> 00:44:35,400 Speaker 1: movie depended on a mixture of different effects. Some of 756 00:44:35,400 --> 00:44:40,000 Speaker 1: them were computer generated and keyed in, some were robotic effects. 757 00:44:40,040 --> 00:44:41,520 Speaker 1: But a lot of this has to do with the 758 00:44:41,520 --> 00:44:45,080 Speaker 1: fact that the effects team as a whole took tremendous 759 00:44:45,200 --> 00:44:48,640 Speaker 1: care to produce results that were really convincing to the eye. 760 00:44:48,840 --> 00:44:52,360 Speaker 1: And that's the story behind chroma key and green or 761 00:44:52,480 --> 00:44:56,360 Speaker 1: blue screen technology. It's a super interesting approach to creating 762 00:44:56,400 --> 00:44:59,920 Speaker 1: a composite moving image, and frankly, there's going to be 763 00:44:59,920 --> 00:45:02,640 Speaker 1: a lot of other topics are around this that I 764 00:45:02,680 --> 00:45:05,400 Speaker 1: can go into. I could probably talk even more about 765 00:45:05,400 --> 00:45:10,279 Speaker 1: optical printers, for example, and the various approaches to film processing. 766 00:45:10,880 --> 00:45:13,279 Speaker 1: And you can see that while the actual chroma key 767 00:45:13,320 --> 00:45:17,080 Speaker 1: process is very different between film and digital video, the 768 00:45:17,160 --> 00:45:20,880 Speaker 1: basic idea of replacing one color or one element in 769 00:45:20,920 --> 00:45:25,280 Speaker 1: a shot with something from a totally different source remains 770 00:45:25,320 --> 00:45:29,000 Speaker 1: the same. It's the same underlying principle. No matter what 771 00:45:29,040 --> 00:45:34,759 Speaker 1: the actual process is. Yeah, yeah, this this screen bean 772 00:45:34,840 --> 00:45:39,960 Speaker 1: cast role is tight, y'all. Oh my god, mashed potatoes? 773 00:45:40,600 --> 00:45:44,920 Speaker 1: Who invented mashed potatoes? That give that person all the 774 00:45:44,960 --> 00:45:50,960 Speaker 1: Nobel prizes? Okay, that's it for the classic episode tech 775 00:45:51,000 --> 00:45:52,799 Speaker 1: Stuff in front of the grade screen. I hope you're 776 00:45:52,800 --> 00:45:58,720 Speaker 1: having as filling a Thanksgiving as I am. It's great, 777 00:45:59,239 --> 00:46:01,959 Speaker 1: very thankful for you, every one of you. I'm gonna 778 00:46:02,000 --> 00:46:04,879 Speaker 1: go take a nap, and next week we'll be back 779 00:46:04,920 --> 00:46:09,160 Speaker 1: with all new episodes. That should be very well rested 780 00:46:09,160 --> 00:46:12,959 Speaker 1: because I planned to sleep for about eighteen hours. Take care, 781 00:46:13,640 --> 00:46:23,280 Speaker 1: and I'll talk to you again really soon. Tech Stuff 782 00:46:23,400 --> 00:46:27,920 Speaker 1: is an iHeartRadio production. For more podcasts from iHeartRadio, visit 783 00:46:27,960 --> 00:46:31,480 Speaker 1: the iHeartRadio app, Apple Podcasts, or wherever you listen to 784 00:46:31,520 --> 00:46:36,319 Speaker 1: your favorite shows.