How a Biologist Builds a Digital Camera


okay this is super weird because I can’t
see, you guys… but hello YouTube! I’m Kurtis Baute and this is the Scope of
Science and I just built I built a digital camera. Okay wait a
second, we’re gonna start from the very beginning. You see, this isn’t really a
video about the camera that I built but it’s about how I built it. People often
ask how the eye, in all its complexity, could have possibly evolved, and I
actually think it’s a great example of evolution. Now since the eye is actually a lot like camera – well the camera is a lot like an
eye – I’ve decided to evolve a digital camera, one step at a time, so that at
each step it still worked. So this is that process. I start by making something
that can sense light it’s a photocell and I’m going to make mine using a
copper penny. You see metals like copper give off
electrons when they’re exposed to light and by adding some heat and some
saltwater to a plate of copper I can actually make that effect big enough
that I can measure it. Animals also see light by using chemistry and electrical
charges just instead of copper its proteins and instead of wires it’s
neurons. Now I can take the number value that I get and represent it as a degree
of brightness a lower number is darker and a higher number is brighter. Now to
make a camera I’m gonna need a lot of these but since I don’t have 2.8 billion
years to evolve the camera (and that’s how long it took for life to evolve
vision) I’m just gonna take a couple short cuts and I’m gonna order a bunch
off of Amazon. This photocell is more compact than my penny but if I connect
it to my Arduino brain-computer thing I can use it in pretty much the same way.
If I put a bunch of these photocells together I get a sensor and now I can
measure light even better and now I can finally start to tell if maybe there’s a
predator swimming above me and if it’s casting a shadow onto me. That’s really
important information to have! This is what life might look like for a Hydra:
they can see light and dark but that’s about it. Now I’m going to build a wall
up around my sensors so that light entering one side casts a shadow on some
of my photo cells. If light enters from the left side of my sensor it casts
light on the right side, if it enters from the top it casts light on the
bottom. I can now use my camera to sense directionality it can see if light is
coming from over there or if there is a predator coming at me from behind this
is what life might look like for flatworms their eyes are just little
sensors in a cup the bigger this wall gets the smaller the hole becomes and
the more directionality I can see eventually I can close that hole almost
all the way until it’s just a pinhole – we call that a pinhole camera. And it’s not
very sensitive so I need to use a lot of really bright lights so that it can
receive an image and since I’m using so many bright lights I have to wear these
glasses to protect my eyes because it’s blinding otherwise so I can’t really see
you guys. But I built this digital camera using 16 photo cells and a pinhole box
and the image you see from it is currently in black and white and it’s
just 16 pixels so it’s pretty extremely low resolution but hopefully you can
make out my selfie. Hi! And the image you see from it is upside down and backwards
because of how light goes through this hole in the front of this camera. The
image is upside down and backwards because, remember if light enters from
the left side it shows up on the right and if it enters from the top it shows
up on the bottom. I can use computer software to rotate and flip that image.
In life that software is stored in brains. It would be good if we had a
colour image and we can do that with a little grade school math
and physics. All of the light we see is made of just three primary colours: red,
green, and blue. Mix them together and you get purple, or well, I mean, you get the
idea. If we specialize our photocells so that each one only detects one colour; say
we cover it with a red filter so that only red light gets onto that one… we can
see how much red is in the image, or how much blue is in the image, or how much
green, too. The thing is that each photocell needs a value for each colour purple
is lots of red, lots of blue, but no green. But we can use the power of averages for
this this photo cell senses red and it uses its neighbour to figure out how much
green and blue is nearby. Computing that we get: purple. our eyes actually work
like this, they have three photo cells called rods
ones four red ones four green and one is for blue. Now my camera it can see colour
so let’s take a look out my window it’s a little pixelated but… I mean okay, it’s
it’s really… it’s really pixelated. After spending a lot of hours trying to
upgrade my camera from sixteen pixels to 81 pixels…
after all that, finally… I gave up when I realized that this was the best possible
image I could get from an 81 pixel camera in the best-case scenario. And yes
it’s cool but it’s just not good enough because I want to show you how lenses
work and I can’t do that with this level of resolution. So, I just upgraded from 16
pixels to over 2 million pixels using one of the camera bodies that I already
owned, and this is the image you get with that and it’s blurry because I still
haven’t added a lens to it. This is still just a pinhole camera it’s a piece of
cardboard with a pinhole in it so the light goes directly onto the sensor. This
is the world through the pinhole eyes of the Nautilus: it’s dark and blurry, but
there are images and colour. For the next step we’re going to add a very simple
lens… Behold! The water droplet. Yes, just a single
droplet of water can act as a magnifying glass, and this is something that you can
try at your own risk on your smartphone. It will act as a macro lens making very
tiny things very large to your sensor so that you can zoom into tiny little
things like the Canadian flag on the sleeve of the astronaut on the
five-dollar Canadian bill. Lots of snails have simple lens eyes like this.
Now that lens is still pretty crude so we’re gonna bring it up to the next
level. This crazy-looking image that’s kind of blown out on the sides is what
you get if you just use a magnifying glass in front of the pinhole. It’s
better than nothing but it’s still kind of distorted on the outside, but
hopefully this gives you an idea of the focus that a piece of glass or our
droplet of water can give you in making an image. I finally look like a real
person! Okay, a weird person but I thats how I normally am. Now there are more
tweaks you could do in evolving a camera, like being able to change the size of
the pinhole, or change the distance between the pinhole and the lens. All of
those things can change and improve the image that you get but I think by now
you should get the idea of how a camera works and how a camera or an eye could
evolve. Something really cool happened while I was working on this project but
before I get into that if you feel like you’ve learned something so far please
consider subscribing to this channel you’ll SEE the button for it below… if
bad puns don’t make you subscribe what will!? ok.. ok. So while this project evolved
the code that I was writing got messier and messier because I kept adding new
code but since it usually wasn’t worth my time to delete the old code that I
was no longer using it kind of just became clutter and just built up. Now,
what’s awesome about that is that that’s what actually happens in evolution. Most
of our DNA doesn’t actually do anything anymore – it used to, but it no longer has
a function, and it just kind of stuck around. Scientists call it ‘junk DNA’ and
it makes up most our DNA! Evolution doesn’t solve things
in the best possible way, it just solves things using whatever way is good enough.
That’s why our eyes have a blind spot. You see, the photocells in our eyes are
actually pointing the wrong way they’re pointing away from light so there’s
actually a bundle of nerves where there should be photocells if you want to
find your blind spot, I left instructions in a link in the description. If you
liked this video you can like this video and if you want to learn more about how
evolution works I recommend the book The Selfish Gene by Richard Dawkins. It’s
actually the reason that I started to take science classes in the first place.
The 40th anniversary of the book just came out and I can tell you it stands
the test of time, it is a true classic. You can buy that book using the link in
the description and that link will also help support this channel the Scope of
Science. I also put some links to the camera gear that I use to film the
camera that I made it was meta, right? Anyways thanks so much for watching!

Comments 100

  • On my last video, a lot of people asked what they can do to support this channel – at this point, the biggest way to help out is to help me spread the science!
    Tweet about the video about the camera shot on a camera: https://goo.gl/ZbDW6d
    Facebook my 16-pixel face: https://goo.gl/BZj6X5
    Upboat on Reddit: https://goo.gl/UAY9Fc

    Thanks!!

  • Oh this is incredible, eye opening I'd say.

  • As a biologist, I'd like to point out that cephalopods, nautilus included, don't have cone cells. This means they are not able to see colours in the same way vertebrate eye or digital camera does. While the general eye anatomy is analogous to pinhole camera, you shouldn't have mentioned the colours in that context. Or even point out that nautiluses can actually only see black and white.

    There's cool hypothesis of how some of cephalopods are still able to see colours though. They are thought to change the focus very rapidly, and since different wave lenght have slightly different refractive indexes, rays with different wavelengts that come from the same direction hit the photoreceptors at different times. Then their brain are somehow able to calculate these changing light intensities sensed by the photoreceptors and form very precise idea of the colours of whatever they are looking at. This way cephalopods can keep scanning the world and combine the information, to be able cheat and obtain colourvision.

    Why they are hypothesized to be able to see colours in the first place is because many cephalopod species are able to change the colour patterns on their bodies to match very accurately their surroundings. Nautilus species are still not able to see colours this way either though.

    I hope you occasionally read comments on your older videos, so that I didn't waste few precious minutes of my lifetime typing this 😀

  • This guy deserves more for the quality of this video

  • THAT’s AWESOME !

  • How does this have only about 8,000 views? This is brilliant!

  • really good video

  • dosent work like that "evolution"

  • Why your videos get no more than 20 dislikes

  • This video was really E Y E O P E N I N G .
    But really. And the fact about junk code was the cherry on the cake.

  • this is the best youtube channel i've ever seen, please keep doing these

  • Congrats 1k likes❤️

  • Oh wow this is incredible, thanks so much for sharing this!! I've thought for a good while whether there's a better way to record instead of a digital pixel and more like biology, a live image. This is a great explanation of how the principal of photo celular work goes on, and where the boundary is to the digital world. It seems they're really not too different! Fascinating

  • I never thought learning biology could be this interesting. You rule, man!

  • I was really impressed how you made that "camera" using only those sensors and how you gradually upgraded it until it could know where was the light coming from. Such a wonderful idea!

  • I subscribed, then unsubscribed, then subscribed. Now I wonder about the water drop(s) Sir Stabbington received. 1 or 2? Beware, I am already making evil plans for him, if the answer is 2 😀

  • wtf junk dna made me albino

  • This has got to be the coolest video I have seen in a long time, earned my subscribe. Mad at youtube for not recommending him to me earlier.

  • Alright man, i have not seen an educational video with such a flow and wit since Vsauce kinda stopped uploading. Please keep up the lovely work, you SEE, youve got a new subscriber here!

  • I know I have a blind spot because I found it some years ago, but I cant find it anymore

  • very good indeed

  • I love your videos. Thank you for making them, you are great man!

  • Your channel is gold. Kids could use this to help them better understand what is teached in school.

  • This video should have much more views

  • This is super cool! But green isn’t a primary color. Yellow is primary.

  • super cool! you the man!

  • This is such a genuinely amazing video, great way of explaining the evolution of the eye and I was thoroughly engaged the whole way through. Keep up the great work.

  • This is so satisfying!

  • "The selfish gene" its also the first document that coined for the first time the word "meme"

  • That was such a good explanation

  • That's the camera that pewdiepie uses

  • The only channel I know off that is bell worthy

  • "The Selfish Gene" is really an awesome book, and its sequel, "The Extended Phenotype" as well, also a related book by the same great Richard Dawkins, "The Blind Watchmaker"

  • Very awesome educational content that feels like entertainment. I probably will show this to some of my teachers at some point. You deserve WAY more subscribers, keep it up!

    PS:
    If you took in color information with only red green and blue filters I guess it wouldn't be suitable for Video right? Now that I think about it you are a genius haha.

  • Awesome.

  • This is one I've the coolest things I've seen on YouTube

  • Brilliant

  • I hope this video gets more views, your basic sensor made up of LDRs is amazing even though its resolution is so low, and perfectly explains how the eye evolved.

  • the best video i saw all year

  • The blind spot thing didn't work for me, I got my right eye pressed right against the dot, literally touching my monitor and could still see the cross, lol….

  • Shake some dirt in a box for how much time you want and evolve me a canon 5d

  • Honestly best video on YouTube 🧐😃

  • Como eu vim parar aqui!?
    Que bom!

  • yes and no. junk dna is not junk, we just don't fully understand it yet. junk code on the other hand, I know very well!
    the fact that we can detect a narrow segment of the electromagnetic fields surrounding us is impressive. in order to do it with other wavelengths requires hardware that is also evolving along with computer software. once we figure out more, we will find the solid matter isn't solid, but a different form of electromagnetic radiation we perceive as a solid, and that we are a form of energy, not matter.

  • This is one of the best videos on Youtube

  • Or you could use a single pixel but rotate it around on 2 axes really fast, this is basically how cheap IR homing surface to air missiles work.

  • the best channel on youtube

  • What a positive and fun approach to this topic!

  • DNA doesn't solve anything. Things just happen and the organism runs with it. It's entirely happenstance and completely random. But I'm sure you already know that.

  • I don’t understand why you can call this a way of representing evolution. The thing is that you, as the creator, still have to put all of this together in order to prove your point, but in the process disprove your own argument about a non created, high resolution image sensor. Of course, you bring up the same old saying of “through millions of years of evolution”, the frog won’t turn into a prince with millions of years my friend.

  • He is the most entertaining science teacher

  • :36 whoa! I didn't even know that your eye had a camera shaped lens inside it! No wonder optometrists can so easily repair with laser, they just twist the lens to refocus it.

  • This may be a bit late, but if you would have lined the 81 pixels up in a straight line and just rotated the whole thing you could have gotten an image that has a resolution comparable to about 6000 pixel

  • amazing

  • Can you please post the source code of your java program, I'm very interested in trying this out for my computer science class.

  • I would like to state that the primary colors are not Red Green and Blue, they are Cyan, Magenta, and yellow. There is no way for the colors Red, Green, and Blue to make Magenta or Cyan, but Magenta, Cyan, and Yellow can make Red, Green, and Blue

  • I found my blindspot. It's where my blindspot is.

  • that was so coool!!!!

  • A few points:
    (3:20) Perhaps you could just close your eyes, using your eyelids? :-/
    (4:10) You don't need to do anything in software (nor do our brains have to do any flipping) – just wire it correctly in the first place. Nature doesn't do the wiring 'the wrong way' then fix it in software, and nor do digital cameras. The fact that an image forms on the retina/sensor 'upside down' is as irrelevant as the fact that our eyes are connected to the opposite brain hemispheres, or that the laryngeal nerve wraps around the aorta on its way from the brain to the larynx.
    (9:10) The photocells in our eyes do not "point the wrong way", or any way for that matter. Cells don't point.

  • That was awesome!!

  • Oh my code looks like that when doing lots of changes for my robot and im too lazy to clean it up. I actually was able to solve a bug in the code once by completely rewriting everything.

  • 8:07 -> Immediately subscribed

  • Please make these but with like ear, and muscles and such

  • So cool dude! Keep it up!

  • Awesome video! But I would've loved to see more of your 81 pixel camera! It blows my mind that we can (kinda) see your face IN COLOR with a homemade photosensor!!!

  • Amazing content…I love how you combine photography with science…I'm looking forward to you next video

  • I discovered this channel and wow! never imagined loki can teach sience so good!!!

  • Wow! Such a nice video! Awesome to see people being creative with biology 🙂

  • That junk dna and messy code analogy…. Mind blown..
    My life is complete now.
    (First time viewer)

  • I just can't get over the fact that the hair behind your ears is sweaty. Please shower or get a haircut or something.

  • This was awesome. I was amazed when you added the 81 sensors and whe coud see you on the video

  • I wonder if there is a software that can average those pixels over time and create a high resolution image.

  • But can it shoot in RAW?

  • funny how to the code wrote itself… but cool video

  • Only one word "awesome"….
    My life done about camera perspective

  • smart analogy of the messy code and junk DNA there, but be careful, what used to be called junk DNA appears to have regulatory function that scientists are now studying with the whole genome sequencing and epigenetics, now it's called non coding DNA

  • this is the best explanation on youtube ever

  • how can somebody expalain a complicated topic as simple as this…loved it…

  • Can You Post The Code And Arduino Planout

  • Wow! You are awesome!

  • this should have so much likes

  • This video goes into my Top ten best videos on Youtube playlist

  • This was brilliant!

  • "optical glass? never heard of it, sounds expensive"

  • I cannot wait to take awesome pictures with my eyes and upload it in my computer via my built-in Bluetooth in my brain from a nano-memory card in my brain

  • Awesome video 👍👍👍

  • Very enlightening. Eye-opening stuff. Great way to visualize evolution.

    Please accept these paltry puns as a token of appreciation for sharing the amazing amount of hard work you do.

  • Can you share your code? I want to do something similar but need help.

  • Which programming language did he use ?

  • Do a video on your opinion on intelligient design

  • Why isn't this video on trending?

  • Amazing channel!

  • I just realized that you lived in Canada when you used one of our (now worthless) pennies and it said CANADA on it. Yay Canada!

  • I'm kinda new to the channel so I'm not sure if you've done this, but you should build and evolve the other half of this video. The audio. A microphone, I think that'll be cool to see. Like showing how sound detection has evolved through time

  • Seriously underrated channel

  • …the tiny birthmark camera under the r.eye & projecting on left eye on some of the victims of mk ultra. The inversion trick you explain is why they can make 1 crazy when east west south north affected cognition disturb by emo shock …how twisted to do to a being …
    Finally get it yet so sad that was done … How to rectify such ?…

  • Hey man can you share your code please?

  • Hey man I really want to recreate this project but I know nothing about coding or how to layout each ldr can you share your code or make a simple how to video? Thank you

  • An interesting companion video for this one could be The Weird World in RGB by Technology Connections
    https://www.youtube.com/watch?v=uYbdx4I7STg

    Here they show how you can break down every colour into RGB values, but if you were to light things in only 1 of the 3 colours how our vision breaks down.

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