hey, vsauce. michael here. i am at the white house, in america's capital, washington, d.c. america makes a lot offeature films every year - hollywood. but they don't make the mostfeature films every year. nigeria makes more. but the country that makes the mostfilms every single year is
1 day acuvue color contacts, india. every two years, the country of india fills up enough film with uniquefeature films that stretch all the way from this city,mumbai, to where i live, in london. that's double what hollywoodproduces in two years.
that is a lot of movies, but is real-life a movie? i've discussed the framerate 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 arepixel dimensions. when multiplied they tell us the total number of pictureelements an image is made up of. a figure often used to describe digitalcameras. it might sound like more is better, but to be sure numberslike 1920 by 1080
are not resolutions per se.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, thesize of the sensors, what the millions of pixels are actuallyencoding and how close the subject is. i mean, up close salvador dali's painting of his wifelooking at the mediterranean can be resolved into boxes. but from a far, well, it's abraham lincoln. for crying outloud, 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 oneanother also matters. this is called spatial resolution. for instance, if i go out-of-focus the number of pixels in the video framestays 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, howmany pixels would you need to make an image on a screen large enough to fillyour entire field of view look like real life, without anydetectable pixelation? now we are getting somewhere. kind of. the analogy is still crudy because a camera snaps an entire frameat once, whereas our eyes move around. the brain amalgamates their constant stream of informationinto what we call vision - sight. in fact, the image created by theeyeball alone during a single glance
would hardly even be acceptable on abroken tv screen. we think our eyes create images like this pictureguy 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 evenglasses, if you have them. luckily, our brainsprocess those stimuli out because they don't matter and they don't change. but thinking those arethe only difference is a pitfall, literally,
latinly. the fovea gets its name from the latin for 'pitfall'. the fovea is the pit on yourretina that receives light from the central two degrees of your field of view, about the areacovered by both your thumbs when held at arms length away. optimalcolour vision and 20/20 acuity are only possible within that little area.when it comes to these limitations xkcd[.com] has a brilliant illustration. it points out other problems, like blind spots - literal blank spaces in our vision where the optic nerve meetsup 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 your right eye, fixating your left eyeon a point in front of you, extending your left thumb and then moving it left-of-center slightly slowly carefullyuntil it's not there anymore. crazy(!)but, of course, we don't see the world horribly, likethis, because our eyes are constantly moving, dragging foveal resolution wherever we need it.
and our brains' complex visual system fills in details, merges images from both eyes and makes alot of gueses. what we 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 thisdifference. 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 ofingredients you call perception
is fooled. our vision is not analogous to a camera. but ourreformulated question can still be answered because human anatomy allows usto resolve, to differentiate certain angular distances. famously, roger n .clark used a figure of 0.59 arcminutesas the resolution of the human eye to calculate, based on the size of our total field ofview, how many of these distinct elementscould fit inside of it. the result was an approximation ofexactly what we want to know: how many individual picture elements -pixels - our vision can appreciate.
his answer? 576 megapixels. that many pixels, packedinside a screen large enough to fill your entire field of view, regardless of proximity, would be close enough to be undetectableby the average human eye. but we should factor in the fovea, because clark's calculation assumesoptimal acuity everywhere, it allows the eye to move around. but a single glance is more analogous toa camera snap, and, as it turns out, only about 7 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 mightsound low but keep in mind that there are plenty of modern technologies thatalready use pixel densities better than we can differentiate.as bad astronomer deftly showed, apple's retina displays truly docontain pixels at a density average eyesight can't differentiate from typical reading distances. but the fact thatthere 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 acamera sensor we only have a finite and discrete number of cells in our retina. but the brain adjusts our initialsensations 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 notsaved in memory with veracity like a
digital camera file. absolutely no evidence has ever beenfound for the existence of a truly photographic memory. and what's evencooler is that not only do we not visually resolve the real world, like a movie camera, we also don't narratively resolveconflict and drama in our lives like most movie scripts. the point ofall 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 it's a special kind of movie.cinematic victories and struggles are often
discrete, resolved, like pixels, withunbelievably 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 adecision and then walk away from the camera across the street and have the creditsroll, freezing life in a perfect happily ever after. but in the real world, after you crossthe 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 beforeyou came around and it will continue running after you are gone. your life is a plotonly in so far as it begins and ends and occurs in medias res. damerish opens illustration forcharles mcgrath's endings without endings says it perfectly. in life, there rarely is
the end. there is only the and. and as always, thanks for watching.
