B1 中級 1958 タグ追加 保存
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


What Is The Resolution Of The Eye?

1958 タグ追加 保存
Penelope Aries Black 2014 年 12 月 13 日 に公開
  1. 1. クリック一つで単語を検索


  2. 2. リピート機能


  3. 3. ショートカット


  4. 4. 字幕の表示/非表示


  5. 5. 動画をブログ等でシェア


  6. 6. 全画面再生


  1. クイズ付き動画


  1. クリックしてメモを表示

  1. UrbanDictionary 俚語字典整合查詢。一般字典查詢不到你滿意的解譯,不妨使用「俚語字典」,或許會讓你有滿意的答案喔