CCD: The heart of a digital camera (how a charge-coupled device works)

Bill takes apart a digital camera and explains how its captures images using a CCD (charge coupled device). He also shares how a single CCD is used with a color filter array to create colored images. This video is based on a chapter from the EngineerGuy team's latest book Eight Amazing Engineering Stories (Learn more at www.engineerguy...)

[@drmoss_ca]

I knew Bill Boyle, who invented the CCD at Bell Labs, and had the pleasure taking his portrait with a CCD-based camera (a Leica M9) around the time he was awarded the Nobel for his work. A lovely and modest guy, he brought in his medal in a carrier bag and let me hold it!

[@BigEightiesNewWave]

Co-inventor sorry. George Elwood Smith (born May 10, 1930) is an American scientist, applied physicist, and co-inventor of the charge-coupled device (CCD). He was awarded a one-quarter share in the 2009 Nobel Prize in Physics for "the invention of an imaging semiconductor circuit-the CCD sensor, which has become an electronic eye in almost all areas of photography".

[@markowalski1]

Best ending yet. "This sounds implausible, but you've seen the results yourself."

[@diamondsmasher]

Flying butt monkeys create rainbows in the sky as they dance in rhythm for the pleasure of their god, the Flying Spaghetti Monster. This sounds implausible, but you've seen the results yourself.

[@Celaena_Auditore]

"if it didn't happen, you wouldn't see me in colors right now" lol

[@incartravelguide]

Bill, you guys are doing absolute sterling work! I produce video lectures for Deaf Learners in South Africa, and as an engineer I'm totally fascinated by your presentations. Keep up the good work!

[@mustaphahadjiommar8450]

😅😅

[@tofuninja5489]

I really liked how you said at the end "It seems implausible." It does sound like it would be but of course it is possible. It's why I love learning about everything in our world. Who would have thought such ingenuity would create something that we might have thought impossible to the world of possible.

[@ketanmishra007]

got a Digital Image Processing exam starting in almost 3 hours. You are an angel. ;)

[@KellyVergara]

I like his super power that allows him to disassemble things at blinding speeds.

[@MigTheFalz]

Do you realizr it's sped up Edit: I was pretty much a dumbass kid back when I made this comment

[@MigTheFalz]

*realize

[@kanjakan]

@@MigTheFalz Do you realize it's a joke? Well, of course you don't, dummy!

[@MigTheFalz]

It's whatever, it is of course sped up with the magic of editing

[@MigTheFalz]

Sorry about that though, let's just say that it's some kind of a joke.

[@HassanOmariprofile]

wow, most comprehensible video on today's cameras. His voice just makes it easier to understand any topic

[@energysage9774]

I once had an opportunity to collect some data from the SARA observatory. It used several (about 7-12) separate CCDs, each designated to specific wavelengths of light, including infrared and ultraviolet. You could set the exposure time and which CCDs to use for each image. It's great having that sort of control over the process, since you can just increase the exposure time for more distant stars and also focus on the wavelengths that the type of star you're studying happens to emit.

[@philareilly]

Thank you Bill. These excellent videos prompted me to buy your latest book and I look forward to its delivery! I hope that you continue to make videos of such excellent quality, but what I would love even more is to see you spend some more time going into even greater detail on each of the technologies.

[@Xanifur]

Simply astounding. They can now use this information to do thousands of frames per second, even more astonishing, we can construct over 1Trillion frames per second video.

[@Earbly]

I've seen the video of the trillion frames per second camera. Technically speaking, as far as I understand and remember, that footage of the light beam is a "composite" of multiple shots. Obviously the result is still incredible, but it's not really film once and play back, from what I remember

[@ffggddss]

CCD arrays were starting to make their way into (professional) astronomy 40+ years ago. They were hitting the amateur astronomy consumer market maybe a decade or less after that. Then, not too much later, they were making their way into the general consumer market in the form of digital cameras. Like all things tech, they've advanced by leaps and bounds since then. Especially liked his explanation of the trick used to get color from single pixels - in effect, the color information is reduced in terms of total pixel count, so that the illuminance info is at full resolution, while the color info is less detailed. This works, because the human eye doesn't see color info in a scene, in as great detail as overall illuminance. Neat!!

[@erickpassos]

There's a bit more to it: luminance is not completely preserved because each color filter (rgb) blocks the light/luminance that comes with part of the spectrum that's blocked. This is the reason why the grid has twice as many green pixels than reds and blues (2/4 green, 1/4 red and 1/4 blue): the human eye is more sensitive to green, so in order to preserve luminance the most, green must be captured in more detail. Neat++

[@michaelwoodhams7866]

When I was an astronomy student c1990, we had engineers in our department building a CCD camera. Some of the CCD detectors cost over $100k each. (If you want to see the results of this camera, do a web search on Sloane Digital Sky Survey. The UV sensitive CCDs were the very expensive ones.)

[@michaelwoodhams7866]

CCDs revolutionized astronomy. You could easily do digital processing and measurement and automate such measurements, but more importantly CCDs are about 40 times more sensitive than ordinary photographic film, and about 5 times as sensitive as super-sensitive-bizarrely-processed astronomical film. Suddenly you could do with a 1m telescope what had previously been done with a 2m or 4m telescope.

[@shjxhdjdjxh]

​@@michaelwoodhams7866 Welcome l hope help me orphansneedWe putdifficulthe havechildrenWe needyesterdayno There isfor us housing livingtentmy seekersThe helphelpsickneed medicineuntilinsurancehealthyCut offAbout MeI hope helpI have Proof my wordspay when God

[@Thegamer-ey9py]

As always a great video, thank you! I kind of wish you would have spent more time on how the CCD transfers the data from the Pixels.

[@Cyberj717]

Somebody get this guy a TV Show already!.. These need to be longer!

[@pineapplepenumbra]

"This sounds implausible..." And it is. I'm going to stick with believing that tiny elves or imps paint the pictures.

[@kahlzun]

They had that for a while, but the imps evaporated, and kept spilling their paint if the camera was jostled.

[@Hotrodelectric]

So that's where all the unemployed Keebler elves go. I was wondering why my DSLR smelled like a shortbread cookie.

[@andodide]

IMPS? RIP AND TEAR WITH YOUR CAMERA

[@danr1920]

It's just magic, plain and simple. Just like have airplanes fly.

[@pineapplepenumbra]

@@kahlzun You clearly know more about the nature and working of imps than you should do...

[@maxsanandreas1]

A very Thanks to Bill for making these videos.....these are very knowledgeable and you can learn a lot from it.....I hope you keep making these....cheers!!

[@alphabeets]

Man, that is AMAZING technology. I had no idea how high tech it is. Thank you again for the great videos.

[@Vehshya]

Glad to see that you have returned! I can't wait to see more videos coming out!

[@glenben92]

your videos are absolutely excellent.

[@azntranc3951]

Thank you Bill for the very informative video ! This video had me :O the entire time. Please continue to make Engineer Guy videos, despite how long it takes to make one :D

[@TechTopHat]

Got the book to support the show but these videos are awesome! Keep them coming!

[@Gergination]

As fantastic as always. I bought the book as a show of support for you and your crew as much as to learn things.

[@ferbilkers]

I have that exact same Pentax and I love it! No light meter, no electronic anything. It's amazingly simple.

[@sandpatch133]

My jaw drops every time a new video comes.

[@jtggrant87]

Excellent once again. I love the quick looks and simple yet very scientific explanations on basic but marvelous tech.

[@serdoslayer]

Just wanted to stop by and say your video's are AWESOME :D . Thx for all the effort you put into them :)

[@asdfasdf734]

Could you give more hints as to how the CCD can shift the charges down one line at a time? It's hard for me to imagine.

[@codzomz]

(1/2) I am currently reading his book in which he illustrates it and details it a little bit more so here it goes... From a simplified perspective, the key to moving the electrons is the charge of the MOS (metal oxide semiconductor). What's really amazing about a CCD is that it alternates a charge of about .5 and .10 volts between each pixel and MOS, as it does this it changes the actual location of where the electrons hang out within each row of the silicon slab... A higher voltage means that the electrons are closer to the surface, while a lower voltage (.10 V in this example) gives room for electrons to fall to the base of the silicon to let protons take their place at the surface (since we know light is both a partial and a wave, we know that both of these items would exist within the Silicon after it has been exposed to light to take an image). The key is the voltage fluctuation, as the voltage to the adjacent row falls to match the one next to it, the electrons now have an option

[@codzomz]

(2/2) of where they want to hangout BETWEEN pixels as apposed to just where in the silicon they can hangout within a SINGLE pixel. But this doesn't last long, as the CCD now makes the charge of the old location a higher voltage and forces the electrons to stay in its new found location on the CCD (which is just now one pixel or row over to the right, if we imagine the flow in the video). That's it! Now just repeat and repeat this flow of voltage fluctuations enough, and the electrons end up at the end of the CCD and read by the camera as a measure of light exposure, and thus an image is created. Just imagine you put a marble on top of a piano key and you wanted to move the marble down the piano without ever touching it, to do so you would press down the adjacent key and lift the first key the marble was on to force it over one, and then just continue that process. That's what a CCD does except the marble is an electron and the piano key is the CCD's individual rows. Hope this helped!

[@bzakie2]

+Dana Ludwig Yes he seemed to skim over a couple of things in that one. How does it shift the charges down and how does it know what colour the adjacent pixel is?

[@LeninPolimorfed]

Adjacent pixels colour is known because colour filter array geometry is known. It's simply hardcoded into image processor.

[@michaelwoodhams7866]

Short version: Those aluminium electrodes over the top can create an electrical potential barrier, a wall which separates pixels, but this 'wall' can be raised or lowered depending on whether you apply a voltage or not. Each pixel spans three times the distance between electrodes. Electrodes are connected so that every third one is connected, so we have three sets of electrodes, say A, B, C. Now use capital letters to represent the 'wall' state, lower case to represent no wall. We start in state Abc (i.e. AbcAbcAbcAbc...) Charge can accumulate between the walls, in the 'bc' space. We hold it like this during exposure. Now to read out we cycle the voltages on the electrodes. We shift to state ABcABcABC... which shifts the charge which was in 'bc' spaces all into 'c'. Then we go to aBcaBcaBc (charge shifts to 'ca' spaces) then aBCaBCaBC (charge in 'a' spaces) then abCabCabC, then AbCAbCAbC then back to AbcAbcAbc and the charges have all shifted rightwards one pixel. At the end of each row you catch these little buckets of charge and send them off to analogue-digital converter(s) to turn them into numbers. If you overexpose, the potential barriers caused by the electrodes are insufficient to contain the charge, and it leaks into adjacent pixels. The barriers in the perpendicular direction are caused by doping in the silicon and are much more resistant to leakage. This means overly bright lights cause streaks in one direction (e.g. vertical) but not the other (horizontal.)

[@harsh231]

Finally ! Felt like its been ages since we last saw your videos! :)

[@Spr4yzz]

Thanks for this very informative video! I've been wanting to know this for a while now but I've always believed that I had to study electronics for a longer period of time to be able to understand it simply but you explained it in about 4 minutes. I love your videos and I hope you will make many more, once again, thank you!

[@ahmadtajy7178]

"It sounds implausible but you've seen the results yourself." How poetic!

[@zkjgrty]

Simple operation yet such a complicated process. Technology is awesome

[@DanieleGiorgino]

Your videos are always a pleasure to watch. Thank you!

[@misanthrophex]

I just can't grasp the amount of incredibly smart people out there.

[@jimr4002]

Perfectly explained, still utterly incredible.

[@lr937]

Lord almighty. Feeling like the first humans discovering fire.... no matter how well explained the topic is, I am amazed every time I watch this videos, thx again! This should be the way schools educate the new generations... I mean ...in my humble opinion

[@michaelc9217]

My first camcorder had 3 CCDs and that was one of its selling points.

[@foadrightnow5725]

"Any sufficiently advanced technology is indistinguishable from magic!". I'd say that statement certainly applies here! All through the manipulation of electrons! Mindblowing!

[@daniw8903]

I teach digital photography and more students than you might think are looking for detailed explanations of the underlying technology ! Showing this day one!

[@ummtone]

Yesss!! I was looking forward for more videos from you!

[@christopherhite4088]

Kudos on your very well produced, interesting and informative videos. I have watched and enjoyed them all. I will definitely be taking a look at your books. Hope to see more videos in the future. Keep up the good work!

[@dylanreilly6888]

Fantastic explanation! Your students must be lucky to have you, keep up the good work.

[@4lifeNerdfighter]

Yay, EngineerGuy is back!

[@JLuVeeGee]

The part on the color extrapolation is awesome.

[@GNator]

Thanks for the awesome videos, great and simple explanations about technologies we take for granted

[@TechInspected]

Wow, this is pretty awesome. Like I was watching Discovery or National Geographic there. Keep up the good work sir!

[@shjxhdjdjxh]

Welcome l hope help me orphansneedWe putdifficulthe havechildrenWe needyesterdayno There isfor us housing livingtentmy seekersThe helphelpsickneed medicineuntilinsurancehealthyCut offAbout MeI hope helpI have Proof my wordspay when God

[@crytek1224]

I believe you are a bit wrong. Exposing the CCDs to light doesn't make them get charge. When taking a photo the CCDs go like this: 1. They are connected the the battery and build up charge. 2. That charge is measured. 3. The CCD is expesed to light (during this process it discharges, so loses electrons) 4. The shutter closes and the new charge is measured and computed the difference between the initial and the final value. 5. The result is read line by line as you mentioned in the video. Please correct me if i'm wrong :D Btw, your videos rock. Keep up the good work!

[@unfa00]

I think it may have been simplified in the video for the sake of brevity.

[@slowshaun]

the ccd sensor was replaced by the cmos. it would have been nice to hear about that instead. never-the-less, still enjoyed learning how they work. i can't wait to see more of your videos.

[@ManishKumar-hp7vp]

Hi Hammack, Your videos are exceptionally well. You explained the technical section is such a way it is crystal clear to everyone. Your video on bioscope camera particularly the exact matching of sound with corresponding film. Regards. Love to see more videos

[@Arflindine]

Semi-pro photographer here. You are correct, cameras with three separate CCD sensors produce a more accurate image. However, as Mr. Hammack mentions in the video, a single CCD sensor is much more affordable to build, and the results are more than adequate for everyday use.

[@svenv]

Again a brilliant video Mr Bill

[@tannerboy1991]

thanks, this really helped me out on my engineering themed "human eye vs Digital camera" project, cheers!

[@shlomobo]

Another reason why the filtering works so well, is that our eyes are much more sensitive to changes in light intensity than to changes in color - so it is very reasonable to have the color information extrapolated from much less data.

[@gaijinboricua]

Wow! impressive, just impressive. It makes me appreciate more cameras in mobile phones.

[@AintBigAintClever]

I was expecting a phone call from the wife at the end, asking where the digital camera was :) Good video as always.

[@Jon.S]

Great videos Bill, glad your new series is here, and I'll be grabbing the book - I hope it does well so you can promote your "good work" even further - your passion for engineering and communicating it's wonders are obvious to all.

[@ehhhhhhhhhh]

I'm a physics student and a photographer. Thank you for this!

[@moristar]

I would buy that book! So intriguing :) Thanks Bill!

[@ThinkSmartCreative]

You are in a word BOSS. I am just fan of your videos

[@russell28533]

wow, thats a great breakdown. Glad to see new videos too :) Keep up the good work.

[@bashkillszombies]

I'm starting to really like Bill the Engineer Guy, he's no Nye, but he's definitely engaging and a great source of learning for kids and adults alike.

[@c4r1s66]

I wish I liked this guy because the videos are just so good. They're so hard to watch though because the smugness is off the charts, and it's almost like it drips from your voice.

[@pinki2101]

Great Video !! Simply well explained, thank you!

[@mimjack]

your videos make me go 'wow' every time!

[@carolinechin]

YAY YOU'RE BACK!!! :D Been waiting forever for a new video :)

[@Mike_Muffler]

Bill is the coolest. Love ole Billy. #GreatVids #GreatInfo #FeedMyBrain

[@ehhhhhhhhhh]

Your videos are fantastic. I'd vote for you to get a show on the Science Channel, the Discovery Channel, or PBS.

[@tehks0032]

Astute viewers may have noticed that in the colour filter array, there are as many green pixels as there are red and blue pixels put together. This deliberate decision made by engineers is called a Bayer filter (Wikipedia it). The short reason for why there are so many green pixels is because the human eye is more sensitive to green than it is to red and blue; that is, we can "fudge up" red and blue estimates a bit more, but if we mess up the green, we might actually notice.

[@012mke]

He's back! awesome!

[@thethyregod]

HE'S BACK!

[@FauzanZaid]

Thanks a lot!! I had been waiting for it for so long!! Congrats!!

[@coolCharizard]

The three primary colors of light are Red Green and Blue (RGB). In our eyes, we have cones that filter for each of these three colors, and we "see" color based on the brain's interpretation of the sum of those three color amounts. In elementary school, you probably learned the primary colors as Red, Blue, and Yellow. Sometimes in art these are considered the "primary" colors of pigment; however, this is simply a color triad, and there is nothing more special about it than that.

[@coloradofotomatt]

Excellent video. I'm adding this to my outline for Basic Digital Photography which I teach at Colorado Mountain College. Thanks! Matt Lit

[@Quokkat7]

LOL, you are the only channel I have to e-mail me when a new video comes out, LOL

[@christopherconnolly5340]

What a wonderful explanation, not complicated, but didn't feel dumbed down either.

[@oscarbarrios]

In an ocean full of people who praise dumbness, the engineer guy saves humanity, yet again. Thank you sir.

[@jimmysgameclips]

This was fascinating, I've always wondered how digital cameras work. Subbed :D

[@hotgluegunguy]

As far as I know, pixels are square and not rectangular as shown in the video. That's why digital cameras have a higher horizontal resolution than the vertical, because the entire picture is rectangular. Other than that, a great video with fine explanations as always!

[@LifeGeneralist]

I didn't know this before. Thanks so much

[@AppA]

Awesome to see a new video!

[@skybike89]

You make learning fun and enjoyable.

[@RingoLoadagain]

Excellent video! Very clear and understandable.

[@TestingPyros]

That is amazingly impressive! Yeah, I knew it worked, but seeing it this way is pretty hard to believe well!

[@TheMelihTube]

Dear Mr Hammack, I really love your videos. I am always happy to see them in my subscription box. I could read all this information on Wikipedia, but i prefer to see your videos on KZbin. It is much more interesting then sitting in front of an large article. I am currently 17 years old, and I want to be an Engineer just like you. Please, keep doing these videos. :) Greetings from Germany :)

[@shjxhdjdjxh]

Welcome l hope help me orphansneedWe putdifficulthe havechildrenWe needyesterdayno There isfor us housing livingtentmy seekersThe helphelpsickneed medicineuntilinsurancehealthyCut offAbout MeI hope helpI have Proof my wordspay when God

[@Chippelito]

YOUR HAIRCUT IS AWESOME.

[@jsnadrian]

Added the book to my short list. You'll probably be getting some of my money soon...

[@enceladus32]

You are so good at explaining things. Do you have a video on touch screens or refrigerators?

So great, useful and educative video!!! thank you!!! TPS Patagonia.

[@RagnarRipper]

I absolutely love your videos! Thank you for your work! I'm definitely buying the book.

[@klieulessness]

Great video! Worth the wait!

[@fr0nage]

Wow! Thank you! I've always been curious of how my camera works!

[@dionelr]

I keep mine proudly displayed on my bookshelf above my vinyl.

[@sandpatch133]

Engineerguy, I know that you have part of it coming but I would like to request a larger part of navigation systems such as Loran-C, Galileo, GPS, and Inertial navigation systems. I learn about them in the maritime university and it is quite interesting to see what ways they have to increase accuracy. For example thing like eLoran. Thanks for your videos! Greetings from Norway!

[@shjxhdjdjxh]

Welcome l hope help me orphansneedWe putdifficulthe havechildrenWe needyesterdayno There isfor us housing livingtentmy seekersThe helphelpsickneed medicineuntilinsurancehealthyCut offAbout MeI hope helpI have Proof my wordspay when God

We so thank you for your video. The Planetary Society, Patagonia, Argentina.

[@Gringo_In_Chile]

The reason that I decided to play this video is because, I noticed that the 35mm SLR film camera that you used in this video, is the same camera (my first) that I used throughout high school! The Honeywell Pentax (Spotmatic). Boy I miss that camera. I wonder whatever happened to it.... ? Ken

[@BearMeOut]

whoa the no wire part blew my mind

[@raguaviva]

finally back!!!!

[@psyworm]

i'm glad to see a new video. keep them coming. :)

[@Zemnmez]

Really helped with my A2 Astrophysics.

[@LTF85199]

Finally a video... thankx

[@AD-ng4mz]

Awesome. Nicely explained.

[@kazemsabokroo680]

Dadiridy

[@BubuSnow93]

It depends on how you are "making" the colours. You use RBY (more precisly, it's Cyan, Yellow and Magenta) when you add pigments that ABSORB colors to create the black. This is what happens when you mix different paints and the color gets darker. You use RGB to create white with 3 light sources, and it's what happwns when you mix different lights (like your Pc monitor does with 3 different colors of pixel) to create the other colours!