CCD: The heart of a digital camera (how a charge-coupled device works)
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- Опубліковано 14 тра 2012
- 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.com/elements)
- Наука та технологія
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!
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".
Best ending yet. "This sounds implausible, but you've seen the results yourself."
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.
"if it didn't happen, you wouldn't see me in colors right now" lol
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!
😅😅
I like his super power that allows him to disassemble things at blinding speeds.
Do you realizr it's sped up
Edit: I was pretty much a dumbass kid back when I made this comment
*realize
@@MigTheFalz Do you realize it's a joke? Well, of course you don't, dummy!
It's whatever, it is of course sped up with the magic of editing
Sorry about that though, let's just say that it's some kind of a joke.
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.
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.
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
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.
"It sounds implausible but you've seen the results yourself." How poetic!
got a Digital Image Processing exam starting in almost 3 hours. You are an angel. ;)
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.
"This sounds implausible..." And it is. I'm going to stick with believing that tiny elves or imps paint the pictures.
They had that for a while, but the imps evaporated, and kept spilling their paint if the camera was jostled.
So that's where all the unemployed Keebler elves go. I was wondering why my DSLR smelled like a shortbread cookie.
IMPS? RIP AND TEAR WITH YOUR CAMERA
It's just magic, plain and simple. Just like have airplanes fly.
@@kahlzun You clearly know more about the nature and working of imps than you should do...
Somebody get this guy a TV Show already!.. These need to be longer!
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.
(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
(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!
+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?
Adjacent pixels colour is known because colour filter array geometry is known. It's simply hardcoded into image processor.
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.)
wow, most comprehensible video on today's cameras. His voice just makes it easier to understand any topic
"Any sufficiently advanced technology is indistinguishable from magic!". I'd say that statement certainly applies here! All through the manipulation of electrons! Mindblowing!
I just can't grasp the amount of incredibly smart people out there.
Man, that is AMAZING technology. I had no idea how high tech it is. Thank you again for the great videos.
I have that exact same Pentax and I love it! No light meter, no electronic anything. It's amazingly simple.
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.
Simple operation yet such a complicated process. Technology is awesome
I teach digital photography and more students than you might think are looking for detailed explanations of the underlying technology ! Showing this day one!
your videos are absolutely excellent.
Perfectly explained, still utterly incredible.
thanks, this really helped me out on my engineering themed "human eye vs Digital camera" project, cheers!
My first camcorder had 3 CCDs and that was one of its selling points.
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!!
Excellent once again.
I love the quick looks and simple yet very scientific explanations on basic but marvelous tech.
Got the book to support the show but these videos are awesome! Keep them coming!
The part on the color extrapolation is awesome.
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!
Glad to see that you have returned! I can't wait to see more videos coming out!
Great Video !! Simply well explained, thank you!
Thanks for the awesome videos, great and simple explanations about technologies we take for granted
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!!
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++
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.)
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.
@@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
Your videos are always a pleasure to watch. Thank you!
As fantastic as always. I bought the book as a show of support for you and your crew as much as to learn things.
My jaw drops every time a new video comes.
Fantastic explanation! Your students must be lucky to have you, keep up the good work.
What a wonderful explanation, not complicated, but didn't feel dumbed down either.
Again a brilliant video Mr Bill
Yay, EngineerGuy is back!
I didn't know this before. Thanks so much
Wow! Thank you! I've always been curious of how my camera works!
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
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
Just wanted to stop by and say your video's are AWESOME :D . Thx for all the effort you put into them :)
Excellent video! Very clear and understandable.
your videos make me go 'wow' every time!
You make learning fun and enjoyable.
Great video! Worth the wait!
Thanks a lot!! I had been waiting for it for so long!! Congrats!!
Awesome to see a new video!
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
Wow! impressive, just impressive. It makes me appreciate more cameras in mobile phones.
I absolutely love your videos!
Thank you for your work!
I'm definitely buying the book.
Finally ! Felt like its been ages since we last saw your videos!
:)
I would buy that book! So intriguing :)
Thanks Bill!
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.
Excellent video. I'm adding this to my outline for Basic Digital Photography which I teach at Colorado Mountain College. Thanks! Matt Lit
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!
He's back! awesome!
This was fascinating, I've always wondered how digital cameras work. Subbed :D
Yesss!! I was looking forward for more videos from you!
wow, thats a great breakdown. Glad to see new videos too :) Keep up the good work.
Thank you very much. That really helps clear things up!
Awesome video. i have some serious googling to do now.
In an ocean full of people who praise dumbness, the engineer guy saves humanity, yet again. Thank you sir.
Your videos are awesome. Thank you very much.
So great, useful and educative video!!! thank you!!! TPS Patagonia.
Awesome.
Nicely explained.
Dadiridy
Thanks, that was brilliant. Much appreciated!
Great explanation, thanks sir!
Finally a video... thankx
HE'S BACK!
That is amazingly impressive! Yeah, I knew it worked, but seeing it this way is pretty hard to believe well!
Love the information, thanks for the video.
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.
Great videos !!! thanks for posting on youtube!
i'm glad to see a new video. keep them coming. :)
I keep mine proudly displayed on my bookshelf above my vinyl.
awesome!! great channel and content!
Great video!!
So amazing
I'm a physics student and a photographer. Thank you for this!
YAY YOU'RE BACK!!! :D Been waiting forever for a new video :)
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.
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.
awesome video - thanks!
YOUR HAIRCUT IS AWESOME.
This is amazing.
finally back!!!!
whoa
the no wire part blew my mind
Great one Bill
yay! Glad to see this in the sub box :)!
Cool! Technology is like an magic.
Wow, this is pretty awesome. Like I was watching Discovery or National Geographic there. Keep up the good work sir!
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
LOL, you are the only channel I have to e-mail me when a new video comes out, LOL
You are so good at explaining things. Do you have a video on touch screens or refrigerators?
Love these!
Ok, I'm sold, buying your book :-)
And that's why professional videography gear always come with 3 CCD/CMOS chips for each colour, RGB to eliminate the need for the Bayer Filter.