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  • Hey Vsauce

  • Michael here. I am at the White House in America's capital

  • Washington DC America makes alot of feature films every year

  • Hollywood but they don't make the most feature films every year Nigeria makes more

  • but the country that makes the most films every single year is

  • India every two years the country

  • of India fills up enough film with unique feature films

  • that stretch all the way from this city, Mumbai, to where I live

  • in London that's double what hollywood produces in two years

  • that is a lot of movies but is

  • real-life a movie? I've discussed the frame rate of the human eye before but how

  • does the resolution

  • of the human eye compare to a camera or screen?

  • VHS, laserdisc, DVD

  • Blu ray, IMAX. Numbers like these are pixel dimensions when multiplied

  • they tell us the total number of picture elements an image is made up of

  • a figure often used to describe digital cameras it might sound like

  • more is better but to be sure numbers like 1920 by 1080

  • are not resolutions per say more pixels is only part

  • of the equation. Resolution is about distinguishing

  • fine details and that depends on a lot of other factors

  • for instance the amount of light the sizeof the sensors

  • what the millions of pixels are actually encoding and

  • how close the subject is I mean up close

  • Salvador Dali's painting of his wife looking at the Mediterranean can be

  • resolved into boxes but from afar

  • well it's Abraham Lincoln. for crying out loud on a small enough screen

  • from far enough away low and high so-called resolutions on screens aren't

  • even resolved differently

  • from one another by your eye

  • how different nearby pixels are from one another also matters this is called

  • spatial resolution

  • for instance if I go out-of-focus

  • the number of pixels in the video frame stays the same but you can't resolve as much

  • detail now with all this in mind we can still

  • compare human vision to a digital image by asking a better question

  • assuming everything else is optimal how many pixels would you need to make an

  • image on a screen large enough to fill your entire field of view

  • look like real life, without any detectable

  • pixelation? Now we are getting somewhere

  • kind of. The analogy is still cruddy

  • because a camera snaps an entire frame at once whereas

  • our eyes move around. The brain amalgamate

  • their constant stream of information into what we call vision

  • sight, in fact the image created by the eyeball alone during a single glance

  • would hardly even be acceptable on a broken TV screen. We think

  • our eyes create images like this picture Guy took of me with a camera

  • but for one thing unlike a camera you've got some stuff

  • in the way for instance you are always

  • looking at your own nose and maybe even glasses

  • if you have them. Luckily our brains process those stimuli out because they

  • don't matter

  • and they don't change but thinking those are the only difference

  • is a pitfall, literally

  • Latinly. The fovea gets its name from the Latin for

  • pitfall, the fovea is the pit on your retina that receives light from the

  • central two degrees

  • of your field of view about the area covered by both your thumbs

  • when held at arms length away. Optimal colour vision and 2020 acuity

  • only possible within that little area when it comes to these limitations XKCD

  • has a brilliant illustration

  • it points out other problems like blind spots literal blank spaces

  • in our vision where the optic nerve meets up with the retina

  • and no visual information is received if you bought

  • a camera that did this you would return it

  • you can find your own blind spot by closing

  • you're right eye fixating your left eye on a point in front of you

  • extending your left thumb and then moving it

  • left-of-center slightly slowly carefully until

  • it's not there anymore crazy but of course

  • we don't see the world horribly like this because our eyes are constantly moving

  • dragging foveal resolution where ever we need it

  • and our brains complex visual system fills in details

  • merges images from both eyes and makes a lot of gueses what we can actually see

  • is a processed image not computer-generated imagery but

  • well meat generated imagery the neon color spreading illusion

  • is a great way to demonstrate this difference there is no

  • blue circle in this picture the white here

  • is the same as the white here, a camera

  • isn't fooled, a screen isn't fooled, only

  • you and the fleeting gumbo of ingredients you call perception

  • is fooled. Our vision

  • is not analogous to a camera but our reformulated question can still be

  • answered because human anatomy allows us to resolve to differentiate certain

  • angular distances famously Roger N Clark

  • used a figure of 0.59 arcminutes as the resolution of the human eye to calculate

  • based on the size of our total field of view

  • how many of these distinct elements could fit inside of it

  • the result was an approximation of exactly what we want to know

  • how many individual picture elements pixels our vision can appreciate

  • his answer 576 megapixels

  • that many pixels packed inside a screen large enough to fill

  • your entire field of view regardless of proximity

  • would be close enough to be undetectable by the average

  • human eye. But we should factor in the fovea

  • because Clarks calculation assumes optimal acuity everywhere, it allows the

  • eye to move around

  • but a single glance is more analogous to a camera snap and as it turns out

  • only about seven megapixels packed into the two degrees of

  • optimal acuity the fovea covers during a fixed stare

  • are needed to be rendered undetectable it's been roughly estimated that the

  • rest of your field of view would only need about

  • 1 megapixel more information. Now that might sound low but keep in mind that there

  • are plenty of modern technologies that already use pixel densities

  • better than we can differentiate as bad astronomer deftly showed

  • Apple's Retina Display's truly do contain pixels at a density

  • average eyesight can't differentiate from typical

  • reading distances but the fact that there are screen sizes and pixel

  • densities that can fool the human eye

  • is not a sign that we see in

  • any kind of megapixelly way human vision just

  • isn't that digital I mean sure like a camera sensor we only have a finite

  • and discrete number of cells in our retina

  • but the brain adjusts our initial sensations into a final perception

  • that is a wishy-washy top-down processed blob

  • of experience it's not made of pixels

  • and furthermore unlike a camera it's not saved in memory with veracity like a

  • digital camera file

  • absolutely no evidence has ever been found for the existence of a truly

  • photographic memory and what's even cooler is that not only do we not

  • visually resolve the real world like a movie camera

  • we also don't narratively resolve conflict and drama in our lives

  • like most movie scripts. The point of all of this what I'm getting at

  • is an idea an idea that initially drew me to this question

  • we play roles in the movie of life

  • but its a special kind of movie cinematic victories and struggles are often

  • discrete resolved like pixels with unbelievably perfect beginnings and endings

  • whereas the real world is all about ear resolution

  • I like how Jack Angstreich put it in cinemania

  • in a movie a character can make a decision and then walk away from the camera

  • across the street and have the credits roll freezing life in a perfect happily ever after

  • but in the real world after you cross the street

  • you have to go home the world goes on

  • life doesn't appear in any particular pixel resolution

  • or narrative resolution things are

  • continuous the world was running before you came around and it will continue running

  • after you are gone your life is a plot only in so far as it begins

  • and ends and occurs in medias res

  • Damerish opens illustration for Charles McGrath's endings

  • without ending says it perfectly in life they're rarely is

  • the end, there is only

  • the and and as always thanks for watching

Hey Vsauce

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B1 UK camera resolution eye human eye vision pixel

What Is The Resolution Of The Eye?

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