1 00:00:09,234 --> 00:00:13,610 KRISTEN: So our next keynote speaker is Alex Lorman. 2 00:00:13,610 --> 00:00:17,054 He is an engineer, but he has also 3 00:00:17,054 --> 00:00:18,860 been a professional photographer. 4 00:00:18,860 --> 00:00:23,890 And he's going to tell you what's inside the camera, 5 00:00:23,890 --> 00:00:27,802 and all the physics behind it, and some cool things 6 00:00:27,802 --> 00:00:29,370 cool he's done with his own cameras. 7 00:00:29,370 --> 00:00:31,030 So I'm going to turn it off to Alex. 8 00:00:31,030 --> 00:00:31,530 Thank you. 9 00:00:31,530 --> 00:00:34,100 ALEX LORMAN: I promise to bore you all to death with physics. 10 00:00:34,100 --> 00:00:35,820 It will be great, I promise. 11 00:00:35,820 --> 00:00:39,200 So like Kristen mentioned, I currently work as an engineer. 12 00:00:39,200 --> 00:00:42,620 I build robotic boats right now, which is all kinds of fun. 13 00:00:42,620 --> 00:00:46,370 But I used to build cameras and take pictures in a former life. 14 00:00:46,370 --> 00:00:48,890 It's OK, you guys can all have two careers, too. 15 00:00:48,890 --> 00:00:49,980 This is what I do. 16 00:00:49,980 --> 00:00:52,850 I play with sunken ships, and now I build them. 17 00:00:52,850 --> 00:00:53,360 It's great. 18 00:00:53,360 --> 00:00:54,470 It's good times. 19 00:00:54,470 --> 00:00:57,880 So also for cameras, helicopters are really useful if you ever 20 00:00:57,880 --> 00:00:59,440 want to take cool pictures. 21 00:00:59,440 --> 00:01:03,920 You should go out and ask your parents for one. 22 00:01:03,920 --> 00:01:07,230 So this is actually a camera I built. And that shot-- 23 00:01:07,230 --> 00:01:09,300 the picture on the left-- and before you all say, 24 00:01:09,300 --> 00:01:11,460 no, you didn't possibly shoot that picture-- I did, 25 00:01:11,460 --> 00:01:13,620 and I can show you the raw feed from it. 26 00:01:13,620 --> 00:01:16,980 So it's actually a really old style of camera 27 00:01:16,980 --> 00:01:18,360 that used to use film. 28 00:01:18,360 --> 00:01:21,240 How many of you actually loaded a film camera. 29 00:01:21,240 --> 00:01:21,740 Awesome. 30 00:01:21,740 --> 00:01:22,080 Wow. 31 00:01:22,080 --> 00:01:24,200 That's actually more than I would have expected. 32 00:01:24,200 --> 00:01:25,908 So film is the thing, we'll get into that 33 00:01:25,908 --> 00:01:28,220 in a couple of slides. 34 00:01:28,220 --> 00:01:31,990 This was a digital film hybrid camera. 35 00:01:31,990 --> 00:01:35,667 So actually the whole front unit is a film camera 36 00:01:35,667 --> 00:01:37,500 and it had a platen glass, which is what you 37 00:01:37,500 --> 00:01:39,500 used to use to focus the image. 38 00:01:39,500 --> 00:01:41,940 So before auto-focus and before fixed focus, 39 00:01:41,940 --> 00:01:44,120 you actually had to focus a picture, which involved 40 00:01:44,120 --> 00:01:45,500 moving pieces of glass around. 41 00:01:45,500 --> 00:01:46,830 It was super fun. 42 00:01:46,830 --> 00:01:49,900 And then the thing at the rear takes a picture of that. 43 00:01:49,900 --> 00:01:52,610 So it's a really weird set up, but it also worked, 44 00:01:52,610 --> 00:01:54,410 and I made it in my basement. 45 00:01:54,410 --> 00:01:55,900 So you guys can, too. 46 00:01:55,900 --> 00:01:59,680 Honestly, it's kind of fun to go to a camera store, or eBay, 47 00:01:59,680 --> 00:02:03,930 or Amazon, or wherever, and pick up old used large format camera 48 00:02:03,930 --> 00:02:04,810 gear. 49 00:02:04,810 --> 00:02:07,500 And you can do some fun stuff with it. 50 00:02:07,500 --> 00:02:09,570 So this did shoot the image on the left. 51 00:02:09,570 --> 00:02:13,380 You see it has a really sort of odd, dreamy quality to it. 52 00:02:13,380 --> 00:02:16,160 That was in 2008. 53 00:02:16,160 --> 00:02:18,310 But it can do some interesting stuff. 54 00:02:18,310 --> 00:02:20,880 Most of the Secret Service will think you have a bomb. 55 00:02:20,880 --> 00:02:22,370 But that's OK. 56 00:02:22,370 --> 00:02:25,160 So I've built some other cameras as well. 57 00:02:25,160 --> 00:02:27,120 You can build time lapse cameras. 58 00:02:27,120 --> 00:02:30,130 This is taking apart go pros and soldering things onto them 59 00:02:30,130 --> 00:02:32,570 so that microcontrollers-- similar to the Raspberry 60 00:02:32,570 --> 00:02:35,610 Pi's-- actually, a lot simpler than the Raspberry Pi's-- could 61 00:02:35,610 --> 00:02:37,922 control them and take a picture every-- 62 00:02:37,922 --> 00:02:40,130 I think this was taking a picture every half an hour, 63 00:02:40,130 --> 00:02:41,060 something like that. 64 00:02:41,060 --> 00:02:43,185 So it actually turned the GoPro on, take a picture, 65 00:02:43,185 --> 00:02:44,480 and then turn it off again. 66 00:02:44,480 --> 00:02:46,730 And you guys are actually building something much more 67 00:02:46,730 --> 00:02:48,799 sophisticated than that, so if you guys can all 68 00:02:48,799 --> 00:02:50,340 do your stuff today, you're way ahead 69 00:02:50,340 --> 00:02:52,530 of where I was a couple years ago. 70 00:02:52,530 --> 00:02:53,580 It'll be great. 71 00:02:53,580 --> 00:02:55,140 So that was also solar powered. 72 00:02:55,140 --> 00:02:57,172 That was fun. 73 00:02:57,172 --> 00:02:58,880 That was-- why is my clicker not working? 74 00:03:02,450 --> 00:03:03,070 There we go. 75 00:03:03,070 --> 00:03:04,340 So this shot this. 76 00:03:04,340 --> 00:03:06,100 It will give you a minute of time lapse. 77 00:03:06,100 --> 00:03:08,290 That stayed on the top of a mountain on a project 78 00:03:08,290 --> 00:03:11,530 I was working on for-- it stayed up there for like six or eight 79 00:03:11,530 --> 00:03:12,810 weeks or something. 80 00:03:12,810 --> 00:03:14,550 I only give you a minute of it. 81 00:03:17,517 --> 00:03:18,600 It worked out pretty well. 82 00:03:18,600 --> 00:03:21,030 It was a fun little project. 83 00:03:21,030 --> 00:03:23,800 Time lapses are cool when they actually show something. 84 00:03:23,800 --> 00:03:26,220 In this case, they're not actually showing very much. 85 00:03:26,220 --> 00:03:29,590 So there's one or two cool shots where you get a nice sunrise. 86 00:03:29,590 --> 00:03:30,270 There we go. 87 00:03:30,270 --> 00:03:31,810 Isn't that pretty? 88 00:03:31,810 --> 00:03:35,010 All right, we won't bore you with any further details. 89 00:03:35,010 --> 00:03:38,952 So, cameras and how they've developed. 90 00:03:38,952 --> 00:03:40,660 I'm sure there are further notes on this, 91 00:03:40,660 --> 00:03:42,830 and this is not an exhaustive history of cameras, 92 00:03:42,830 --> 00:03:44,280 so don't quote me on any of it. 93 00:03:44,280 --> 00:03:46,160 In fact, I might even be making it up. 94 00:03:46,160 --> 00:03:47,650 I probably am. 95 00:03:47,650 --> 00:03:49,540 Apparently in 1839, photographs were 96 00:03:49,540 --> 00:03:51,920 on paper that probably had something to do with chemicals 97 00:03:51,920 --> 00:03:52,930 that reacted to light. 98 00:03:52,930 --> 00:03:54,380 I'm just guessing. 99 00:03:54,380 --> 00:03:57,080 But in 1861 they seem to have gotten it in color. 100 00:03:57,080 --> 00:03:59,646 Now the thing with both color, digital cameras, 101 00:03:59,646 --> 00:04:01,020 and film cameras, is suddenly you 102 00:04:01,020 --> 00:04:03,622 need to capture three different sets of light. 103 00:04:03,622 --> 00:04:05,580 And that's much more key with digital cameras-- 104 00:04:05,580 --> 00:04:07,920 and you'll see that-- you need to capture red, green, 105 00:04:07,920 --> 00:04:09,870 and blue to make color. 106 00:04:09,870 --> 00:04:13,122 So then apparently in 1884 they made photographic film. 107 00:04:13,122 --> 00:04:15,580 They seemed to have had a pretty good run of that for about 108 00:04:15,580 --> 00:04:19,649 the next 125 years, 150 years. 109 00:04:19,649 --> 00:04:21,640 And in 1936 SLRs. 110 00:04:21,640 --> 00:04:25,040 We'll get into exactly what SLRs do, and how, and why, 111 00:04:25,040 --> 00:04:26,040 in just a second. 112 00:04:26,040 --> 00:04:27,130 That's OK. 113 00:04:27,130 --> 00:04:28,300 Instant photography. 114 00:04:28,300 --> 00:04:30,160 Has anyone actually shot a Polaroid camera, 115 00:04:30,160 --> 00:04:33,440 where you've got like a little thing that you have to shake? 116 00:04:33,440 --> 00:04:34,280 One. 117 00:04:34,280 --> 00:04:34,850 Cool. 118 00:04:34,850 --> 00:04:35,590 OK. 119 00:04:35,590 --> 00:04:37,530 Polaroid used to be a lot more popular. 120 00:04:37,530 --> 00:04:40,800 Remember I was talking about large format cameras before? 121 00:04:40,800 --> 00:04:44,390 You used to check how they shot by shooting a Polaroid, 122 00:04:44,390 --> 00:04:46,410 and then waiting for the Polaroid of develop, 123 00:04:46,410 --> 00:04:48,900 and then putting the proper large format film-- which 124 00:04:48,900 --> 00:04:50,970 was about this big-- into it. 125 00:04:50,970 --> 00:04:55,060 So your subjects couldn't really be going anywhere fast. 126 00:04:55,060 --> 00:04:57,382 So instant photography was a thing. 127 00:04:57,382 --> 00:04:59,840 A little bit before my time, but it definitely was a thing. 128 00:04:59,840 --> 00:05:01,010 I've heard about it. 129 00:05:01,010 --> 00:05:04,150 Auto-focus, we'll get into auto-focus as well. 130 00:05:04,150 --> 00:05:06,710 People used to actually have to manually focus their cameras. 131 00:05:06,710 --> 00:05:08,040 They had all kinds of cool things called 132 00:05:08,040 --> 00:05:09,930 split screens, where you could-- the image 133 00:05:09,930 --> 00:05:12,215 would suddenly snap into focus when you had it right. 134 00:05:12,215 --> 00:05:12,840 Those were fun. 135 00:05:12,840 --> 00:05:15,730 You can actually get them for modern cameras if you want. 136 00:05:15,730 --> 00:05:17,950 Kodak digital camera. 137 00:05:17,950 --> 00:05:21,247 So they basically took a-- I think it was an Icon F5-- 138 00:05:21,247 --> 00:05:22,830 and just stripped the entire thing out 139 00:05:22,830 --> 00:05:24,510 and put electronics in it. 140 00:05:24,510 --> 00:05:28,020 They were horribly, staggeringly expensive, slow, 141 00:05:28,020 --> 00:05:29,780 and didn't work all that well. 142 00:05:29,780 --> 00:05:32,306 And really the only people who used them were newspaper 143 00:05:32,306 --> 00:05:34,680 photographers because they needed to get their images out 144 00:05:34,680 --> 00:05:35,550 as fast as possible. 145 00:05:35,550 --> 00:05:38,420 They were also about-- the first ones were like one megapixel, 146 00:05:38,420 --> 00:05:39,970 maybe not even that. 147 00:05:39,970 --> 00:05:41,550 They were horrible. 148 00:05:41,550 --> 00:05:47,490 And that continued for a while, until 1998 with modern DSLRs. 149 00:05:47,490 --> 00:05:49,309 Modern DSLRs are really amazing, and what 150 00:05:49,309 --> 00:05:51,100 you can get for a couple of hundred dollars 151 00:05:51,100 --> 00:05:52,700 is unbelievable. 152 00:05:52,700 --> 00:05:56,010 So, a 2012 is the gigapixel camera. 153 00:05:56,010 --> 00:05:58,190 Apparently-- I'm told-- that is a camera that 154 00:05:58,190 --> 00:06:01,650 has like 92 lenses that all shoot at the same time 155 00:06:01,650 --> 00:06:03,924 and creates a gigapixel image. 156 00:06:03,924 --> 00:06:06,090 If any of you can tell me what a gigapixel image is, 157 00:06:06,090 --> 00:06:07,130 that would be great. 158 00:06:07,130 --> 00:06:08,780 Because I don't know. 159 00:06:08,780 --> 00:06:11,410 But I can tell you about DSLRs. 160 00:06:11,410 --> 00:06:15,310 So-- even have a few here. 161 00:06:15,310 --> 00:06:17,140 This looks pretty familiar to everyone? 162 00:06:17,140 --> 00:06:17,640 Cool. 163 00:06:17,640 --> 00:06:18,990 Great. 164 00:06:18,990 --> 00:06:20,760 Ahead of the curve so far. 165 00:06:20,760 --> 00:06:21,440 This bit, too? 166 00:06:21,440 --> 00:06:22,370 Lenses? 167 00:06:22,370 --> 00:06:25,300 Great. 168 00:06:25,300 --> 00:06:28,060 Let's see if they'll actually a couple together. 169 00:06:28,060 --> 00:06:28,870 So, yes? 170 00:06:28,870 --> 00:06:29,890 Still with me so far? 171 00:06:29,890 --> 00:06:31,440 And the make clicking noises? 172 00:06:31,440 --> 00:06:34,090 Fabulous. 173 00:06:34,090 --> 00:06:36,010 So in this wonderful diagram, which 174 00:06:36,010 --> 00:06:39,150 I stole from the internet, the light path goes in 175 00:06:39,150 --> 00:06:40,970 and we get lens elements. 176 00:06:40,970 --> 00:06:43,300 So if you see through lenses, they 177 00:06:43,300 --> 00:06:44,550 have bits of glass in them. 178 00:06:44,550 --> 00:06:46,820 We'll get into much more about how they work. 179 00:06:46,820 --> 00:06:48,820 And I'm probably making half of that up, anyway. 180 00:06:48,820 --> 00:06:50,600 It might just be black magic coming through. 181 00:06:50,600 --> 00:06:51,100 It's fine. 182 00:06:51,100 --> 00:06:52,350 It's not a problem. 183 00:06:52,350 --> 00:06:53,430 The aperture. 184 00:06:53,430 --> 00:06:55,679 So I'll pass around a manual lens for you, 185 00:06:55,679 --> 00:06:57,220 and you can see what the aperture is. 186 00:06:57,220 --> 00:06:59,680 Who can actually-- oh, come on. 187 00:06:59,680 --> 00:07:01,070 Lord. 188 00:07:01,070 --> 00:07:04,470 Who can actually tell me what an aperture is? 189 00:07:04,470 --> 00:07:06,650 Anybody? 190 00:07:06,650 --> 00:07:08,424 Yes, please fire away. 191 00:07:08,424 --> 00:07:10,590 AUDIENCE: [INAUDIBLE] small hole that lets light in. 192 00:07:10,590 --> 00:07:11,298 ALEX LORMAN: Yes. 193 00:07:11,298 --> 00:07:13,820 That is an accurate summary. 194 00:07:13,820 --> 00:07:16,590 So-- here, I'll pass this around. 195 00:07:16,590 --> 00:07:18,610 The aperture ring is on the front. 196 00:07:18,610 --> 00:07:19,980 You hear it click. 197 00:07:19,980 --> 00:07:22,840 Look through the lens, you'll see it change. 198 00:07:22,840 --> 00:07:23,830 Please pass it around. 199 00:07:23,830 --> 00:07:25,060 Just don't lose it. 200 00:07:25,060 --> 00:07:26,110 Awesome. 201 00:07:26,110 --> 00:07:28,520 So she's exactly right. 202 00:07:28,520 --> 00:07:32,090 The aperture controls how much light is coming through. 203 00:07:32,090 --> 00:07:33,590 You say, why on earth would you want 204 00:07:33,590 --> 00:07:35,100 less light to come through? 205 00:07:35,100 --> 00:07:37,790 Can anybody tell me? 206 00:07:37,790 --> 00:07:39,894 Please, the back. 207 00:07:39,894 --> 00:07:43,860 AUDIENCE: [INAUDIBLE] picture doesn't get overexposed. 208 00:07:43,860 --> 00:07:44,610 ALEX LORMAN: Good. 209 00:07:44,610 --> 00:07:46,943 Why wouldn't I just want an obscenely fast shutter speed 210 00:07:46,943 --> 00:07:49,010 instead? 211 00:07:49,010 --> 00:07:51,150 It would freeze everything nice and you could get 212 00:07:51,150 --> 00:07:54,280 exactly the right freeze frame. 213 00:07:54,280 --> 00:07:55,950 Anybody else? 214 00:07:55,950 --> 00:07:58,410 It is-- you're right, you have a correct answer, though. 215 00:07:58,410 --> 00:07:59,427 Please. 216 00:07:59,427 --> 00:08:00,302 AUDIENCE: [INAUDIBLE] 217 00:08:12,609 --> 00:08:13,650 ALEX LORMAN: That's true. 218 00:08:13,650 --> 00:08:16,500 The other one is depth of field. 219 00:08:16,500 --> 00:08:18,249 So if I'm shooting with that wide open-- 220 00:08:18,249 --> 00:08:20,790 and you can sort of see it when you look through the camera-- 221 00:08:20,790 --> 00:08:23,170 you get a really shallow focus point. 222 00:08:23,170 --> 00:08:25,870 And that's great if you're shooting romantic portraits. 223 00:08:25,870 --> 00:08:27,800 But if you're not, you can actually 224 00:08:27,800 --> 00:08:30,930 stop it down-- make it smaller-- and your focus 225 00:08:30,930 --> 00:08:32,152 area will increase. 226 00:08:32,152 --> 00:08:34,360 So suddenly I'll get the first three rows of you guys 227 00:08:34,360 --> 00:08:36,460 in focus instead of just one. 228 00:08:36,460 --> 00:08:38,929 So apertures are really important. 229 00:08:38,929 --> 00:08:41,799 Then it comes in, and bounces up, and then 230 00:08:41,799 --> 00:08:44,110 bounces around five times, and out. 231 00:08:44,110 --> 00:08:46,360 Anybody have a reason why bounces around five times? 232 00:08:46,360 --> 00:08:50,060 Why don't I just put a mirror right there and call it a day? 233 00:08:50,060 --> 00:08:50,560 Great. 234 00:08:50,560 --> 00:08:51,990 I had to look this one up, too. 235 00:08:51,990 --> 00:08:54,840 So it bounces around five times because otherwise it 236 00:08:54,840 --> 00:08:55,980 would be upside down. 237 00:08:55,980 --> 00:08:58,540 And who wants to look through an image upside down? 238 00:08:58,540 --> 00:09:00,582 Personally I don't, but a lot of old view cameras 239 00:09:00,582 --> 00:09:02,998 you do have to look at the image upside down, because they 240 00:09:02,998 --> 00:09:04,710 don't have any optics to flip it over. 241 00:09:04,710 --> 00:09:08,230 It's really easy when you have a developed film to just do that. 242 00:09:08,230 --> 00:09:10,160 But you have to actually focus and compose 243 00:09:10,160 --> 00:09:11,590 the camera upside down. 244 00:09:11,590 --> 00:09:14,880 These were challenges I learned when I was building cameras. 245 00:09:14,880 --> 00:09:18,760 So the sensor and the shutter are two different things. 246 00:09:18,760 --> 00:09:20,910 So you will notice that the light is not actually 247 00:09:20,910 --> 00:09:23,220 going to the sensor or the shutter right now. 248 00:09:23,220 --> 00:09:24,570 We'll get into this in a minute. 249 00:09:24,570 --> 00:09:27,770 Anyway, that whole shebang flips up 250 00:09:27,770 --> 00:09:29,600 and allows light to get to the imager, 251 00:09:29,600 --> 00:09:31,340 and then flips down, in all the time it 252 00:09:31,340 --> 00:09:33,890 takes you to press the button. 253 00:09:33,890 --> 00:09:35,390 It seems complicated, and honestly 254 00:09:35,390 --> 00:09:37,710 it really is complicated. 255 00:09:37,710 --> 00:09:39,870 There are many simpler ways of doing this. 256 00:09:39,870 --> 00:09:42,037 And the cameras you're about to build are simpler. 257 00:09:42,037 --> 00:09:44,620 And thank god, they don't have all these moving parts to them. 258 00:09:44,620 --> 00:09:46,190 It's great. 259 00:09:46,190 --> 00:09:50,080 So we go into parts of the camera a little bit. 260 00:09:50,080 --> 00:09:51,119 We've got a lens. 261 00:09:51,119 --> 00:09:52,160 We talked about shutters. 262 00:09:52,160 --> 00:09:53,300 We'll get into shutters in a second, 263 00:09:53,300 --> 00:09:54,850 they're actually kind of fun. 264 00:09:54,850 --> 00:09:58,260 Flashes, batteries, sensors, LCDs. 265 00:09:58,260 --> 00:10:01,010 This looks pretty familiar to everyone, right? 266 00:10:01,010 --> 00:10:02,400 Great. 267 00:10:02,400 --> 00:10:03,840 Lenses. 268 00:10:03,840 --> 00:10:05,570 This is fun, right? 269 00:10:05,570 --> 00:10:07,761 Come on, we're having fun, aren't we? 270 00:10:07,761 --> 00:10:08,260 Excellent. 271 00:10:08,260 --> 00:10:09,640 Good. 272 00:10:09,640 --> 00:10:10,458 So lenses. 273 00:10:13,270 --> 00:10:13,960 Here's a lens. 274 00:10:13,960 --> 00:10:14,740 We can pass it around. 275 00:10:14,740 --> 00:10:15,250 Don't drop it. 276 00:10:15,250 --> 00:10:16,920 It's already been dropped about five times. 277 00:10:16,920 --> 00:10:17,670 Don't do it again. 278 00:10:17,670 --> 00:10:20,340 It will be unhappy. 279 00:10:20,340 --> 00:10:24,760 So we have wide angles and long lenses, right? 280 00:10:24,760 --> 00:10:26,530 Anybody have any idea why the lenses have 281 00:10:26,530 --> 00:10:29,730 different sizes in the front? 282 00:10:29,730 --> 00:10:30,763 Please. 283 00:10:30,763 --> 00:10:32,655 AUDIENCE: So you can see more-- [INAUDIBLE] 284 00:10:37,870 --> 00:10:38,777 ALEX LORMAN: No, no. 285 00:10:38,777 --> 00:10:39,860 I see what you're getting. 286 00:10:39,860 --> 00:10:41,102 And the answer is, sort of. 287 00:10:41,102 --> 00:10:42,310 I don't mean to call you out. 288 00:10:42,310 --> 00:10:43,580 But, it's sort of. 289 00:10:43,580 --> 00:10:46,630 So this over here is an 8 to 15 lens. 290 00:10:46,630 --> 00:10:48,950 Who can tell me what a focal length is? 291 00:10:48,950 --> 00:10:49,450 Nobody. 292 00:10:49,450 --> 00:10:49,710 Great. 293 00:10:49,710 --> 00:10:50,230 Fantastic. 294 00:10:50,230 --> 00:10:50,801 That's fine. 295 00:10:50,801 --> 00:10:51,300 Don't worry. 296 00:10:51,300 --> 00:10:53,890 So focal length is how wide the lens is. 297 00:10:53,890 --> 00:10:57,590 8 millimeters is really, really, really, shockingly wide. 298 00:10:57,590 --> 00:10:58,810 Like, it's like this. 299 00:10:58,810 --> 00:11:00,420 In fact, that's a fisheye lens. 300 00:11:00,420 --> 00:11:03,100 It's a really nice little lens, but it's hugely wide. 301 00:11:03,100 --> 00:11:05,630 And over there we have a 300 millimeter lens, which 302 00:11:05,630 --> 00:11:08,130 is about this long, costs more than all 303 00:11:08,130 --> 00:11:12,630 of your first cars will, and shoots-- focuses somewhere over 304 00:11:12,630 --> 00:11:15,440 there to begin with, and you can't really focus any closer. 305 00:11:15,440 --> 00:11:16,940 But they're really beautiful lenses 306 00:11:16,940 --> 00:11:18,960 for doing certain things. 307 00:11:18,960 --> 00:11:23,290 So we've covered what focal length is between 8 and 200. 308 00:11:23,290 --> 00:11:25,630 But the aperture is a big thing. 309 00:11:25,630 --> 00:11:29,717 We talked about the aperture and the iris in the lens. 310 00:11:29,717 --> 00:11:31,550 You will not be able to see through the lens 311 00:11:31,550 --> 00:11:32,716 even if you look through it. 312 00:11:32,716 --> 00:11:35,510 I promise you you'll never get it to focus. 313 00:11:35,510 --> 00:11:37,510 But it's a fun try. 314 00:11:37,510 --> 00:11:42,100 So the big expensive lenses let a ton of light in, 315 00:11:42,100 --> 00:11:44,620 and that's why they're big and expensive. 316 00:11:44,620 --> 00:11:45,160 Seriously. 317 00:11:45,160 --> 00:11:47,030 No, that is exactly why. 318 00:11:47,030 --> 00:11:49,490 In terms of optics as well, you'll notice none of these 319 00:11:49,490 --> 00:11:53,980 are 8 to 200 because you can't actually produce 320 00:11:53,980 --> 00:11:55,350 good optics that do that. 321 00:11:55,350 --> 00:11:58,150 It is not within the realm of physics. 322 00:11:58,150 --> 00:12:00,510 People try, and they make really bad lenses 323 00:12:00,510 --> 00:12:02,330 that do like 8 to 200. 324 00:12:02,330 --> 00:12:06,090 And they're about this big, and they're not very good. 325 00:12:06,090 --> 00:12:07,456 That's OK. 326 00:12:07,456 --> 00:12:08,830 Your lenses on the Raspberry Pi's 327 00:12:08,830 --> 00:12:11,530 are moderns of marvel engineering-- of-- you 328 00:12:11,530 --> 00:12:12,810 know what I meant. 329 00:12:12,810 --> 00:12:13,310 All right. 330 00:12:13,310 --> 00:12:13,980 So here's a fun bit. 331 00:12:13,980 --> 00:12:14,604 Here's a video. 332 00:12:14,604 --> 00:12:17,640 So shutters-- we talked about shutters briefly, right? 333 00:12:17,640 --> 00:12:20,130 They expose the imager to light, and then stop, 334 00:12:20,130 --> 00:12:22,590 and they do it in a very precise timing. 335 00:12:22,590 --> 00:12:24,850 So same thing as film. 336 00:12:24,850 --> 00:12:27,649 So we're watching this at 10,000 frames a second. 337 00:12:27,649 --> 00:12:29,190 And I think someone is coming to talk 338 00:12:29,190 --> 00:12:30,648 about high speed cameras, which are 339 00:12:30,648 --> 00:12:32,710 their own really awesome thing. 340 00:12:32,710 --> 00:12:36,760 So we'll watch this again with more narration, if that's OK. 341 00:12:36,760 --> 00:12:40,560 If you all can tolerate 30 seconds again. 342 00:12:40,560 --> 00:12:43,394 So we talked about the mirror flipping up. 343 00:12:43,394 --> 00:12:44,310 There goes the mirror. 344 00:12:44,310 --> 00:12:46,570 This is in one exposure. 345 00:12:46,570 --> 00:12:49,970 Now we see these are all different exposure times, 346 00:12:49,970 --> 00:12:52,170 so they let different amounts of light in. 347 00:12:52,170 --> 00:12:53,040 And you'll see that. 348 00:12:53,040 --> 00:12:57,080 Watch the size of the shutter as it rolls by. 349 00:12:57,080 --> 00:12:57,580 There we go. 350 00:12:57,580 --> 00:13:00,260 See one's much bigger, one's much smaller. 351 00:13:00,260 --> 00:13:02,860 Lets much more light in versus much less light in. 352 00:13:02,860 --> 00:13:05,050 And now the mirror is coming back down. 353 00:13:05,050 --> 00:13:08,390 So you see how phenomenally fast this processes is. 354 00:13:08,390 --> 00:13:12,440 And modern DLSRs can do this on the order of 10 to 14 times 355 00:13:12,440 --> 00:13:13,620 a second. 356 00:13:13,620 --> 00:13:16,530 Which is really cool, and sounds like a machine gun. 357 00:13:16,530 --> 00:13:18,330 That's OK. 358 00:13:18,330 --> 00:13:21,480 So the imagers. 359 00:13:21,480 --> 00:13:23,130 These are the imagers. 360 00:13:23,130 --> 00:13:24,390 Yeah, they're we go. 361 00:13:24,390 --> 00:13:24,890 See? 362 00:13:24,890 --> 00:13:27,850 That's roughly 8 to 10 frames a second. 363 00:13:27,850 --> 00:13:29,480 They go quickly. 364 00:13:29,480 --> 00:13:33,260 So in film, 10 frames a second would last you 365 00:13:33,260 --> 00:13:34,840 about three seconds. 366 00:13:34,840 --> 00:13:39,380 And they actually invented big, high capacity basically 367 00:13:39,380 --> 00:13:42,120 magazines for stuff like sports photographers, 368 00:13:42,120 --> 00:13:44,170 that had 250 shots in them. 369 00:13:44,170 --> 00:13:46,860 And you'd have a roll of film that was about this big. 370 00:13:46,860 --> 00:13:48,450 And they were horrible. 371 00:13:48,450 --> 00:13:52,490 And some cameras got away without the mirror 372 00:13:52,490 --> 00:13:56,050 snapping up and down by having something called a split 373 00:13:56,050 --> 00:13:58,852 mirror, and let some light through and some light up 374 00:13:58,852 --> 00:13:59,560 at the same time. 375 00:13:59,560 --> 00:14:02,530 So you basically got a bad image in both places, 376 00:14:02,530 --> 00:14:05,015 but you didn't have to flip the mirror up every time, 377 00:14:05,015 --> 00:14:07,140 so you could just shoot the film through like there 378 00:14:07,140 --> 00:14:08,610 was no tomorrow. 379 00:14:08,610 --> 00:14:10,050 Sports photography is hard. 380 00:14:10,050 --> 00:14:11,550 If you want to start in photography, 381 00:14:11,550 --> 00:14:14,320 sports is probably not the place because you 382 00:14:14,320 --> 00:14:16,710 need thousands and thousands of dollars of equipment. 383 00:14:16,710 --> 00:14:18,130 Don't worry about it. 384 00:14:18,130 --> 00:14:19,680 This is a CCD. 385 00:14:19,680 --> 00:14:23,271 I am not the right person to tell you exactly how they work. 386 00:14:23,271 --> 00:14:25,770 I'm sure one of the other people that does this for a living 387 00:14:25,770 --> 00:14:29,610 can, and can tell you how to make them in your basement. 388 00:14:29,610 --> 00:14:31,130 Which would be really cool. 389 00:14:31,130 --> 00:14:35,110 But essentially they convert light photons to electricity. 390 00:14:35,110 --> 00:14:37,670 And then the computers in the cameras 391 00:14:37,670 --> 00:14:40,490 convert that to a picture, and then write it to an SD card, 392 00:14:40,490 --> 00:14:41,382 and we go from there. 393 00:14:41,382 --> 00:14:43,590 So the cameras you're going to building, like I said, 394 00:14:43,590 --> 00:14:46,920 are marvels of modern engineering. 395 00:14:46,920 --> 00:14:50,830 All of that-- lens, shutter, focus-- all of that 396 00:14:50,830 --> 00:14:53,780 is built into something that is absolutely tiny 397 00:14:53,780 --> 00:14:56,550 and costs like $25. 398 00:14:56,550 --> 00:14:57,830 It's amazing. 399 00:14:57,830 --> 00:14:59,800 And actually, all of the image processing 400 00:14:59,800 --> 00:15:01,870 is on-board the camera as well. 401 00:15:01,870 --> 00:15:03,730 And it sends it over a communication bus 402 00:15:03,730 --> 00:15:07,400 called SPI, which is a standardized communication bus. 403 00:15:07,400 --> 00:15:11,550 So it's actually incredible what these little cameras can do. 404 00:15:11,550 --> 00:15:14,900 And no, they're never going to shoot as nicely 405 00:15:14,900 --> 00:15:17,710 as the giant piece of glass that's flying around. 406 00:15:17,710 --> 00:15:20,310 But they're also on a chip. 407 00:15:20,310 --> 00:15:23,880 How many of you use your iPhones over a different camera? 408 00:15:23,880 --> 00:15:26,830 Like a smartphone instead of an actual camera? 409 00:15:26,830 --> 00:15:27,340 Most of you? 410 00:15:27,340 --> 00:15:27,881 Don't be shy. 411 00:15:27,881 --> 00:15:29,939 It's OK to admit it. 412 00:15:29,939 --> 00:15:30,480 There you go. 413 00:15:30,480 --> 00:15:31,370 See? 414 00:15:31,370 --> 00:15:34,660 So the marvels of cell phone technology 415 00:15:34,660 --> 00:15:35,660 have brought us to this. 416 00:15:35,660 --> 00:15:38,480 And that's why you can buy it for $25 or $30, 417 00:15:38,480 --> 00:15:39,870 which is still pretty incredible. 418 00:15:39,870 --> 00:15:45,329 And the volume of production for that is unbelievable. 419 00:15:45,329 --> 00:15:47,370 There is a fun trick with that lens, if you want. 420 00:15:47,370 --> 00:15:49,020 If you can hold a smartphone behind it, 421 00:15:49,020 --> 00:15:50,436 you might be able to get the image 422 00:15:50,436 --> 00:15:52,049 to focus on the smartphone camera 423 00:15:52,049 --> 00:15:54,590 and shoot some kind of weirdly distorted, and probably upside 424 00:15:54,590 --> 00:15:56,300 down, picture. 425 00:15:56,300 --> 00:15:59,240 It will probably be upside down because the light is probably 426 00:15:59,240 --> 00:16:01,780 crossing as it goes through to focus. 427 00:16:01,780 --> 00:16:02,280 Maybe. 428 00:16:02,280 --> 00:16:05,456 You can do it with a set of binoculars, too, actually. 429 00:16:05,456 --> 00:16:07,100 AUDIENCE: [INAUDIBLE] 430 00:16:07,100 --> 00:16:08,160 ALEX LORMAN: Nope. 431 00:16:08,160 --> 00:16:10,632 Everyone's welcome to try it. 432 00:16:10,632 --> 00:16:13,215 In fact I'll pass around another lens and we can do that, too. 433 00:16:16,860 --> 00:16:20,455 Again, they're all heavy because they are really fast lenses. 434 00:16:22,790 --> 00:16:23,290 Here. 435 00:16:23,290 --> 00:16:24,456 That's another fun activity. 436 00:16:24,456 --> 00:16:25,110 Go for it. 437 00:16:25,110 --> 00:16:26,484 Just don't drop that one, please. 438 00:16:26,484 --> 00:16:27,894 I really like that one. 439 00:16:27,894 --> 00:16:29,310 If I have to pick one lens, that's 440 00:16:29,310 --> 00:16:30,351 the one I go around with. 441 00:16:32,780 --> 00:16:33,390 All right. 442 00:16:33,390 --> 00:16:33,890 OK. 443 00:16:33,890 --> 00:16:35,790 And please, you can play with smartphones 444 00:16:35,790 --> 00:16:39,520 and try to get a picture if you desperately desire. 445 00:16:39,520 --> 00:16:41,310 Like I said, the Raspberry Pi cameras 446 00:16:41,310 --> 00:16:44,374 are really stunningly amazing, and you can do really fun stuff 447 00:16:44,374 --> 00:16:46,540 with lots and lots of them because they're so cheap. 448 00:16:46,540 --> 00:16:48,390 And I think someone's going to show you 449 00:16:48,390 --> 00:16:51,640 how to do photogrammetric scanning with them, 450 00:16:51,640 --> 00:16:54,030 which is really cool. 451 00:16:54,030 --> 00:16:56,060 But that concludes cameras. 452 00:16:56,060 --> 00:16:58,160 Who has questions about any part of that? 453 00:16:58,160 --> 00:17:00,960 Because we really breezed over like several hundred years 454 00:17:00,960 --> 00:17:03,305 of development and science in 20 minutes. 455 00:17:05,950 --> 00:17:09,940 Who can explain how a shutter works, roughly? 456 00:17:09,940 --> 00:17:11,670 I clearly didn't do a very good job. 457 00:17:11,670 --> 00:17:14,150 Oh, no-- please-- save me. 458 00:17:14,150 --> 00:17:14,650 No? 459 00:17:14,650 --> 00:17:16,650 All right. 460 00:17:16,650 --> 00:17:19,698 What does a shutter do? 461 00:17:19,698 --> 00:17:21,099 AUDIENCE: [INAUDIBLE] 462 00:17:21,099 --> 00:17:22,335 ALEX LORMAN: Please. 463 00:17:22,335 --> 00:17:23,460 AUDIENCE: It lets light in. 464 00:17:23,460 --> 00:17:24,210 ALEX LORMAN: Yeah. 465 00:17:24,210 --> 00:17:25,930 Exactly. 466 00:17:25,930 --> 00:17:26,540 Perfect. 467 00:17:26,540 --> 00:17:27,240 Detector. 468 00:17:27,240 --> 00:17:29,180 It's 10 points for the scientific words. 469 00:17:29,180 --> 00:17:30,131 Very good. 470 00:17:30,131 --> 00:17:30,630 All right. 471 00:17:30,630 --> 00:17:31,130 Excellent. 472 00:17:31,130 --> 00:17:33,830 And apertures, again? 473 00:17:33,830 --> 00:17:36,022 AUDIENCE: [INAUDIBLE] 474 00:17:36,022 --> 00:17:36,730 ALEX LORMAN: Yep. 475 00:17:36,730 --> 00:17:37,540 Perfect. 476 00:17:37,540 --> 00:17:38,200 All right. 477 00:17:38,200 --> 00:17:39,266 Fabulous. 478 00:17:39,266 --> 00:17:40,640 I think I'm going to hand it back 479 00:17:40,640 --> 00:17:42,348 to whoever else is running the show here, 480 00:17:42,348 --> 00:17:44,200 because it's clearly not me. 481 00:17:44,200 --> 00:17:45,630 And hopefully you have enjoyed it. 482 00:17:45,630 --> 00:17:47,190 And hopefully I get all of the lenses 483 00:17:47,190 --> 00:17:48,670 that I passed out back at the end, 484 00:17:48,670 --> 00:17:52,210 otherwise I'm going to sit and cry in the corner. 485 00:17:52,210 --> 00:17:54,210 I promise you, there will be tears. 486 00:17:54,210 --> 00:17:56,210 KRISTEN: Let's give him a big round of applause. 487 00:17:56,210 --> 00:17:57,087 [APPLAUSE] 488 00:17:57,087 --> 00:17:58,170 ALEX LORMAN: Thanks, guys. 489 00:18:02,100 --> 00:18:04,800 If anyone does have questions, please fire away. 490 00:18:04,800 --> 00:18:05,540 No? 491 00:18:05,540 --> 00:18:06,830 Yes, please. 492 00:18:06,830 --> 00:18:08,955 AUDIENCE: Why is that camera called a Raspberry Pi? 493 00:18:08,955 --> 00:18:11,121 ALEX LORMAN: That is a question for the Raspberry Pi 494 00:18:11,121 --> 00:18:12,930 foundation, who's based in the UK. 495 00:18:12,930 --> 00:18:16,480 And I honestly don't know. 496 00:18:16,480 --> 00:18:19,740 No, but seriously, the Raspberry Pi Foundation 497 00:18:19,740 --> 00:18:21,820 is a nonprofit that makes Raspberry Pi, 498 00:18:21,820 --> 00:18:24,110 and they started making the Raspberry Pi camera. 499 00:18:24,110 --> 00:18:26,990 And that's what they do. 500 00:18:26,990 --> 00:18:30,480 I don't have a better answer than that, unfortunately. 501 00:18:30,480 --> 00:18:32,490 Anybody else? 502 00:18:32,490 --> 00:18:32,990 No? 503 00:18:32,990 --> 00:18:35,790 If you really wanted to get into like boards 504 00:18:35,790 --> 00:18:37,930 produced by nonprofits, literally the BBC-- 505 00:18:37,930 --> 00:18:40,480 like the news organization-- just came out 506 00:18:40,480 --> 00:18:43,470 with a tiny little ARM based Linux board, 507 00:18:43,470 --> 00:18:46,257 which they're giving away to all school children in the UK. 508 00:18:46,257 --> 00:18:48,590 Which is pretty cool, actually, when you think about it. 509 00:18:48,590 --> 00:18:50,006 Better yet, they've included tools 510 00:18:50,006 --> 00:18:52,950 to actually do things with it. 511 00:18:52,950 --> 00:18:53,460 All right. 512 00:18:53,460 --> 00:18:54,043 Thank you all. 513 00:18:54,043 --> 00:18:55,290 Appreciate it. 514 00:18:55,290 --> 00:18:56,840 [APPLAUSE]