To Learn How Your Camera Works, Try Building One

Digital cameras are ubiquitous today — even $20 cell phones have them built in. But few people actually know how a digital camera works. Shree Nayar, a computer scientist at Columbia University, set out to change that with his Bigshot Do-It-Yourself Digital Camera kit, which gives tinkerers a view of a camera's anatomy.

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IRA FLATOW, HOST:

This is SCIENCE FRIDAY. I'm Ira Flatow. Chances are, you're carrying a digital camera in your pocket right now. No, it's not - it's hard not to be carrying one. You know, they're built into even the cheapest Smartphones. But do you have any idea how it works? Back in the good ol' days and I mean, oh, 20 years ago, talking about the days of those big clunky film cameras, if you wanted to it wasn't hard to figure out how the camera worked.

You just opened the back up. You could see the mirror, the shutter, the lens. Even saw where the film went across, you know, in the back there. It was easy to imagine how the image ended up on your film. These days, forget about it, as we say here in New York. But maybe my next guest can help demystify the digital camera for us.

He's got a new kit for kids and adults that lets you build a digital camera and you learn as you go along. Yeah. Shree Nayar is a professor of computer science at Columbia University here in New York. Welcome to SCIENCE FRIDAY Dr. Nayar.

SHREE NAYAR: Thank you, Ira. A pleasure to be here.

FLATOW: What was the idea for this camera?

NAYAR: Well, the whole idea is we live in a time when all these gadgets that we use are, just like you said, highly mystified, very dense, very packed and you have really no idea what's going on inside. And soothe whole premise here was to demystify the working of the camera but not just that, not just to describe how a camera works, but use the camera which has tremendous appeal in society as a draw and redesign it so as to convey to the user as many science and engineering concepts as possible.

FLATOW: Mm-hmm. Now, it's called the Big Shot Camera Kit and for everyone who doesn't have one sitting in front of them right now, give us an idea of what this looks like, what it has in it.

NAYAR: Well, it comes as a kit that you put together. Now, the idea here is not for an eight-year-old to necessarily solder all the parts together. There's a lot of precision engineering that goes on in a camera - the optics and the mechanics. So that would be unreasonable.

On the other hand, the idea is to - at a time when things are mystified, like I said, to touch and feel all the underlying components and in the process get exposed to the underlying science concepts. And the design is such that we have included certain features that you wouldn't commonly find in other cameras.

For example, it has a rechargeable battery but if you're out on a shoot and you happen to run out of charge, it also has a power generator that you can crank up manually and generate enough power to take a few photos. Now, as you can imagine, that's not a necessary component of a camera but it's been put in there on purpose so that we can describe to the user how the mechanics of a gearbox works, how electromagnetic induction works, which is the basis of motors and dynamos and so on.

So there's many different features that one would commonly not find in other cameras but have been introduced in the design so as to use them as a pivot into these concepts.

FLATOW: 1-800-989-8255 is our number. Maybe you have one of these Big-Shot Camera Kits. Maybe you'd like to get one. How easy is it to build? It's got to be, you know, as you say, even a child can do it, but not too young a child.

NAYAR: Well, it really is meant for a very wide audience. If it's an eight-year-old I think it would make a wonderful project with a parent or an older sibling. A teenager I think can do the entire thing by themselves. And then of course you also notice there's a very large community of camera enthusiasts who might also pick up a thing or two about cameras during the process.

The entire build process would be somewhere between, I'd say, 30 minutes and an hour but during that process there is also an accompanying website that you can use to learn the underlying concepts. And this is where I think it's a little bit different from many of the science kits out there where you might put it together and play with it a bit and then you sort of move on.

But here you have this website with educational material including a textbook which has nine different chapters and interactive demonstrations that help you visualize the underlying concepts. That's sort of unusual. So if you were so inclined you could just build it and use it, but if you were really interested you could come back again and again to the website and learn various concepts at different levels of depth.

And in this website, some of the topics that we actually cover are those that would be commonly covered at a college level. And we've tried to make it accessible to a very young audience. But in terms...

FLATOW: For example...

NAYAR: ...of build itself - yeah. Go ahead.

FLATOW: For example, what kind of topics?

NAYAR: For example...

FLATOW: Are you talking about?

NAYAR: ...we talk about image processing. You know, I mean, if you think about image processing and how all the things within Photoshop look, for instance, that make images look better and change their geometric structure and distortions and all of that stuff, that's typically something we would cover in a university, but we've tried to explain those concepts in a very simple way on this website.

FLATOW: Do you explain what's actually going on inside those big circuit boards? You know, people have no idea what those little boxes and lines and things...

NAYAR: Yeah.

FLATOW: ...do on that.

NAYAR: Especially these days. Yeah. Absolutely.

FLATOW: Yeah.

NAYAR: I mean, you know, this is the whole thing that - I actually work in a computer science department and as you know we live in an age where software dominates. And the younger generation is getting very comfortable with that. But I do believe we want the next generation to also understand this stuff that software sits on top of.

Get their hands dirty. And so what we've tried to do with electronics - now, of course, with the mechanics, the gearbox and the dynamo and the optics, we let them touch and feel all of that, but when it comes to memory chips and image sensors and input/output and USB works and so on, there's only so much you can go. You can't open these chips up.

FLATOW: Yeah.

NAYAR: But what we have tried to do on the website is have a layout where all the steps that take place from the minute that you hit the shoot button to the capture of the image, the storage, and its display on the screen, all of those things are displayed and shown in a very visual way. You can follow the steps corresponding to each line of software code that sits on the camera.

And so we've really tried our best to try and, you know, make this as visual as possible.

FLATOW: Now that you've given us all - you've whet out appetite about building this camera, can you give us a thumbnail sketch of how a standard digital camera works? Instead of film, how does a digital camera capture an image?

NAYAR: Well, I mean, as you know if you've bought one of these, it's turned into recently a very complex beast. But I'll boil it down to two very important components. The first component is the lens, of course. The lens, the main purpose of it is to capture as much light as possible and then create behind the lens an image of the scene in front of the lens which is as sharp as possible.

To focus light onto a plane. And that technology has evolved, really, over centuries. But where I think there's been very rapid evolution is the image sensor - or the electronic image sensor that's replaced film. And it's a chip. And this chip has on it millions and millions of little pixels. And these pixels are really buckets that collect light - photons - and then convert them into electrons.

And once they have converted them into electrons, then these millions of different measurements have to be read out. And so the chip works really hard at reading these things out in as faithful a manner as possible. In fact, these image sensors have become so sophisticated that they're even able to enhance the quality of the image, remove graininess, make the colors more vivid, and maybe even compress the image for more efficient storage all within the chip.

So we're talking about a chip that might be few tens of milligrams in weight that's able to do things that a large computer couldn't do 20 years ago. And that's where, you know, a lot of the innovation has taken place. So I'll just boil it down to those two major components.

FLATOW: Yeah. Yeah. You know, being an old film person myself, I remember in film and I used to work in a darkroom and do all that kind of hobby stuff. That in film there were different color emulsions on the film itself. How do you get different colors on the chip?

NAYAR: Interesting question because you - I mean, at the end of the day, you can essentially measure one color at each pixel. So what you do is you have different colors being measured by neighboring pixels. So if I'm measuring red then my neighbors are measuring green and blue. And then you put all of that together using image processing techniques. It's a technique called demosaicing. And that's how - that's very different from the way color works.

I mean, sorry, film works.

FLATOW: Yeah.

NAYAR: But that's how digital image sensors create a color range.

FLATOW: All right. Let's go to the phones, 1-800-989-8255. Let's go to Philly. Eva in Philadelphia, hi. Welcome to SCIENCE FRIDAY.

EVA: Hi. Thank you very much for a very interesting program. I know two boys and two men who would love putting together one of these cameras, especially thinking about them for the holidays. Where may I purchase them?

NAYAR: We have a website which is bigshotcamera.com.

EVA: Big Shot?

NAYAR: Bigshot. Bigshot.

EVA: OK

NAYAR: B-I-G-S-H-O-T. Which is a play on words. It's the idea of exposing kids to these concepts and turning them into bigshots.

EVA: Good.

NAYAR: So bigshotcamera is one word, dot com. And the camera is available there online to buy.

EVA: Wonderful.

FLATOW: Eva, do you...

EVA: How much is it?

NAYAR: It's $89.

EVA: Wonderful. OK. Thank you so very much for a very, very...

FLATOW: Are your kids...

EVA: ..interesting information. I love it.

FLATOW: Are your kids hobbyists? They like to build stuff?

EVA: Well, I've tried to teach them as much as possible about scientific things and make them immediate for them. So yes.

FLATOW: Yeah.

EVA: Sometimes they like to build stuff. Sometimes they like to read about stuff. It depends.

FLATOW: Yeah. All right. Thanks for calling.3

EVA: Thank you very much.

NAYAR: Thank you.

EVA: As always, an interesting show.

FLATOW: You're welcome. Thanks. 1-800-989-8255 is our number. Let's see if we can go to Jacob in Valdosta, Georgia. Hi, Jacob.

JACOB: Hi. Thanks for taking my call.

FLATOW: Mm-hmm. Go ahead.

JACOB: My question is what sets this kit apart from other DIY electronics hobby kits and how do you plan on getting these into the hands of, I don't know, students and people who might be interested. I've noticed that the market is saturated with all sorts of DIY projects kits but, you know, what's the plan to get more people interested?

FLATOW: Yeah. You've got all these maker kits and things like that, old Radio Shack stuff.

NAYAR: So let me start with your first question. I think that's a really interesting one. There's lots of fascinating kits out there. There's robots and there's circuits that can build. One of the things that we find that's really interesting about Big Shot is that because of the inherent nature of the camera itself, it allows you to juxtapose the sciences and the arts.

So, you know, you learn and you build and you learn these science concepts but once you're done you have a fully functioning digital camera with which you walk into the world of photograph and storytelling and documentation. And that's the art. So as a teacher or a parent or just a student, you can imagine getting both these experiences within a single process and that's somewhat unusual.

In terms of getting this in the hands of kids, I mean, you know, we have a lot of various conversations that we're having such as this one and hopefully the word will get out and people will get to know about it. But one of the things that we are doing is that a part of the royalties that we get from the sales of cameras, we're using it to gift cameras to highly underprivileged kids in various parts of the world.

We think that that's an important piece of the mission and hopefully as we do well on sales we'll also be able to live out that aspect or position.

FLATOW: I'm Ira Flatow. This is SCIENCE FRIDAY from NPR. Talking with Shree Nayar who is professor of computer science at Columbia University here in New York. Why the camera? Why not part of the phone or something?

NAYAR: Well, once again, I mean, it's - you know, it comes down the fact that the camera is really a unique piece of technology. It allows us to express ourselves, to communicate with each other. Using it is an emotional experience. There really are very few other things like it. I mean, I'm certainly thinking about other gadgets we might be able to use, but is very special.

And so we thought this would be the ideal one to start off with, but also in part because my lab at Columbia does quite a bit of work in computer vision and new types of cameras. So there was also a natural fit there.

FLATOW: Speaking of your lab art, are you working on new types of cameras? What...

NAYAR: So...

FLATOW: Things that might be different?

NAYAR: Yeah. This line of work really started in the mid-'90s when we were interested in building cameras that would create three-dimensional depth images, panoramic images, high dynamic range images that give you more brightness in colors, more colors than red, green, and blue.

So these are very, I would say, more on the high end application side of things. And maybe about seven or eight years ago I started thinking about how we could leverage what we know about cameras to make a social impact, a broader social impact, and that was the genesis of Big Shot.

FLATOW: So are these cameras sort of discounted from where they might be? Are you trying to keep the price down on them or--?

NAYAR: We have worked very hard to keep the price down. And, in fact, one of the reasons we sell online is because we do cut out certain parts of the pipeline and we are able to control the costs. And, of course, whenever you have a product that comes out initially, it's typically made in smaller quantities and therefore the price is difficult to control.

But at $89, if you compare it with many other kits out there, and the fact that after you're done you actually have a fully functioning device that you can use on a daily basis, I think...

FLATOW: Yeah.

NAYAR: ...plus the website that adds quite a bit of value, I think it's fine and we'll see where things go from here.

FLATOW: How do you get the images off the camera? Do you plug it in to your laptop?

NAYAR: It's just - yeah. There's a memory chip on the camera itself. You plug it in using USB.

FLATOW: Ah.

NAYAR: And in fact, there's a piece of software. The camera takes three types of pictures: a regular shot, a panoramic or wide angled shot, and then the third one is interesting. It captures an anaglyph which allows you to wear red-green glasses and see what you've shot in 3D. And as you can imagine, that's interesting for...

FLATOW: Yeah.

NAYAR: ...kids and grownups. And so...

FLATOW: Thank you.

NAYAR: ...the software knows which type of photo has been captured and processes it and produces the final image for you.

FLATOW: Huh. What about the maker movement? You know, the maker fair people, people who show up there? Isn't that sort of doing what you've done with this camera but more on a grassroots scale?

NAYAR: Absolutely. I mean, we just had a maker fair last month here in New York and it's a huge movement and one that I'm extremely excited about. A lot of educators around the world have talked about how making not only fosters learning and creativity but also really makes kids happy. And I would say that the same arguments apply to grownups as well.

It's really, really important. One of the things that we have tried to do here is sort of go the extra mile, which is ask the question is making enough. Because a lot of the concepts that we're talking about are based on very strict laws of nature. You know, let's call them fundamentals.

And these fundamentals, of course, cannot be gained in their full glory through purely making. And I think making is a piece of it and then after that there's the educational material that comes with it.

FLATOW: And you can get the camera where? You can get the camera. The website is?

NAYAR: It's bigshotcamera.com. Bigshotcamera one word, yeah.

FLATOW: All right. Yeah. We have it on our website also. Thank you, Shree.

NAYAR: Thank you so much.

FLATOW: For taking time to be with us.

NAYAR: My pleasure.

FLATOW: Shree Nayar is professor of computer science at Columbia University here in New York.

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