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Hey Vsauce
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Michael here. I am at the White House in America's capital
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Washington DC America makes alot of feature films every year
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Hollywood but they don't make the most feature films every year Nigeria makes more
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but the country that makes the most films every single year is
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India every two years the country
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of India fills up enough film with unique feature films
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that stretch all the way from this city, Mumbai, to where I live
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in London that's double what hollywood produces in two years
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that is a lot of movies but is
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real-life a movie? I've discussed the frame rate of the human eye before but how
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does the resolution
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of the human eye compare to a camera or screen?
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VHS, laserdisc, DVD
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Blu ray, IMAX. Numbers like these are pixel dimensions when multiplied
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they tell us the total number of picture elements an image is made up of
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a figure often used to describe digital cameras it might sound like
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more is better but to be sure numbers like 1920 by 1080
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are not resolutions per say more pixels is only part
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of the equation. Resolution is about distinguishing
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fine details and that depends on a lot of other factors
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for instance the amount of light the sizeof the sensors
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what the millions of pixels are actually encoding and
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how close the subject is I mean up close
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Salvador Dali's painting of his wife looking at the Mediterranean can be
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resolved into boxes but from afar
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well it's Abraham Lincoln. for crying out loud on a small enough screen
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from far enough away low and high so-called resolutions on screens aren't
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even resolved differently
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from one another by your eye
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how different nearby pixels are from one another also matters this is called
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spatial resolution
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for instance if I go out-of-focus
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the number of pixels in the video frame stays the same but you can't resolve as much
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detail now with all this in mind we can still
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compare human vision to a digital image by asking a better question
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assuming everything else is optimal how many pixels would you need to make an
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image on a screen large enough to fill your entire field of view
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look like real life, without any detectable
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pixelation? Now we are getting somewhere
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kind of. The analogy is still cruddy
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because a camera snaps an entire frame at once whereas
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our eyes move around. The brain amalgamate
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their constant stream of information into what we call vision
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sight, in fact the image created by the eyeball alone during a single glance
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would hardly even be acceptable on a broken TV screen. We think
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our eyes create images like this picture Guy took of me with a camera
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but for one thing unlike a camera you've got some stuff
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in the way for instance you are always
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looking at your own nose and maybe even glasses
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if you have them. Luckily our brains process those stimuli out because they
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don't matter
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and they don't change but thinking those are the only difference
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is a pitfall, literally
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Latinly. The fovea gets its name from the Latin for
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pitfall, the fovea is the pit on your retina that receives light from the
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central two degrees
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of your field of view about the area covered by both your thumbs
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when held at arms length away. Optimal colour vision and 2020 acuity
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only possible within that little area when it comes to these limitations XKCD
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has a brilliant illustration
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it points out other problems like blind spots literal blank spaces
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in our vision where the optic nerve meets up with the retina
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and no visual information is received if you bought
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a camera that did this you would return it
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you can find your own blind spot by closing
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you're right eye fixating your left eye on a point in front of you
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extending your left thumb and then moving it
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left-of-center slightly slowly carefully until
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it's not there anymore crazy but of course
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we don't see the world horribly like this because our eyes are constantly moving
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dragging foveal resolution where ever we need it
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and our brains complex visual system fills in details
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merges images from both eyes and makes a lot of gueses what we can actually see
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is a processed image not computer-generated imagery but
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well meat generated imagery the neon color spreading illusion
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is a great way to demonstrate this difference there is no
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blue circle in this picture the white here
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is the same as the white here, a camera
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isn't fooled, a screen isn't fooled, only
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you and the fleeting gumbo of ingredients you call perception
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is fooled. Our vision
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is not analogous to a camera but our reformulated question can still be
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answered because human anatomy allows us to resolve to differentiate certain
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angular distances famously Roger N Clark
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used a figure of 0.59 arcminutes as the resolution of the human eye to calculate
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based on the size of our total field of view
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how many of these distinct elements could fit inside of it
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the result was an approximation of exactly what we want to know
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how many individual picture elements pixels our vision can appreciate
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his answer 576 megapixels
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that many pixels packed inside a screen large enough to fill
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your entire field of view regardless of proximity
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would be close enough to be undetectable by the average
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human eye. But we should factor in the fovea
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because Clarks calculation assumes optimal acuity everywhere, it allows the
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eye to move around
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but a single glance is more analogous to a camera snap and as it turns out
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only about seven megapixels packed into the two degrees of
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optimal acuity the fovea covers during a fixed stare
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are needed to be rendered undetectable it's been roughly estimated that the
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rest of your field of view would only need about
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1 megapixel more information. Now that might sound low but keep in mind that there
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are plenty of modern technologies that already use pixel densities
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better than we can differentiate as bad astronomer deftly showed
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Apple's Retina Display's truly do contain pixels at a density
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average eyesight can't differentiate from typical
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reading distances but the fact that there are screen sizes and pixel
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densities that can fool the human eye
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is not a sign that we see in
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any kind of megapixelly way human vision just
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isn't that digital I mean sure like a camera sensor we only have a finite
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and discrete number of cells in our retina
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but the brain adjusts our initial sensations into a final perception
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that is a wishy-washy top-down processed blob
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of experience it's not made of pixels
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and furthermore unlike a camera it's not saved in memory with veracity like a
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digital camera file
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absolutely no evidence has ever been found for the existence of a truly
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photographic memory and what's even cooler is that not only do we not
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visually resolve the real world like a movie camera
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we also don't narratively resolve conflict and drama in our lives
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like most movie scripts. The point of all of this what I'm getting at
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is an idea an idea that initially drew me to this question
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we play roles in the movie of life
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but its a special kind of movie cinematic victories and struggles are often
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discrete resolved like pixels with unbelievably perfect beginnings and endings
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whereas the real world is all about ear resolution
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I like how Jack Angstreich put it in cinemania
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in a movie a character can make a decision and then walk away from the camera
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across the street and have the credits roll freezing life in a perfect happily ever after
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but in the real world after you cross the street
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you have to go home the world goes on
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life doesn't appear in any particular pixel resolution
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or narrative resolution things are
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continuous the world was running before you came around and it will continue running
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after you are gone your life is a plot only in so far as it begins
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and ends and occurs in medias res
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Damerish opens illustration for Charles McGrath's endings
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without ending says it perfectly in life they're rarely is
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the end, there is only
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the and and as always thanks for watching