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# standard

In this video I will show you how to
find standard deviation and variance for a list of numbers in your TI 30xIIS
scientific calculator. I already have a list of numbers entered into my
calculator, so to find standard deviation I first press the STATVAR button. A
list of values shows up at the top of my screen, and so in order to find standard
deviation, which is labeled sample is Sx and population as Sigma X, I need to move
this little line at the top of the screen. To do that I just press the over
arrow and whatever is highlighted is the number that shows at the bottom. So if I
underlined SX that would be my sample standard deviation, that is this number
on the screen. If I go over one more spot this number here would be my population
standard deviation. So I can go back and forth and find both. To find variance all
you have to do is make sure one is underlined and press equals. That will
bring you to this screen where you can then square the standard deviation, that
will give you variance. So after you press the squared button hit Enter
and this number on the screen will give you variance. You can do this for both
sample standard deviation and population standard deviation. So this is how to
find standard deviation and variance for both population and sample in your
scientific calculator.

Edge Finders are simple devices they’re very handy for referencing your
machine in the workplace one problem is that they are so common
manufacturers often assume you know how to use them and don’t bother to provide
instructions the mechanical edge finders shown here
is a classic model this will set you back about ten dollars.
The basic model has a cylindrical tip which is two hundred thousands of an inch in
diameter it has two sections the body and the tip. The edge finder has three modes; Orbiting, Centered and Offset. It has found the edge at the transition
point between centered and offset. This is about half a thousands
of an inch for that transition. Here it centered… …there it’s offset. Now we move back a little bit… And it snaps back onto center. The transition between centered and offset is half of thousands of an
inch… …five ten thousands of an inch. Remember when you find that transition
point that’s not zero, the tip of the edge finder is two hundred
thousands of an inch in diameter. The radius is a hundred thousand of an inch. Your position is… …one hundred thousand or a tenth of an inch
offset from… the actual true center. The electronic edge finders works in a similar
fashion, but they have an LED light which
indicates when you touch. An electronic indicator like this will set
you back for twenty dollars if you get a.. …better discount house… …brand name ones are about fifty dollars. They are generally about two tenths of a thousand’s of an inch… …point zero zero zero two… for accuracy

In this clip I’m going to be showing you how
to use a Casio graphical calculator in order to find standard deviation in a typical statistics
S1 exam question. So here we have a typical exam question. It
concerns itself with the number of items going through a checkout and so we’ve got the various
values here and the number of times that they occurred. We need to find the mean and standard deviation
of the number of items the customers had, so in order to do that if we didn’t have a
graphical calculator, we might be doing a long-winded method whereby we transpose a table, add two
extra columns to it for fx and fx squared. You’d have to calculate these by typing them
all into our calculator rapidly one after the other, add them all up to find the totals,
and then substitute them into the formula. Now there isn’t anything particularly hard
about doing all this. It’s just that it’s quite a long process and there is a possibility
to make a mistake somewhere along the line and therefore mess up your final answer. An alternative way would be to use your calculator
to do it. Now this is an A-Level exam so I can’t just type in all the numbers and write
down the answer and expect to get all five marks sitting there. I do need to show method
in an A-level exam, so I want to show you firstly how to use the statistics options
in your calculator, and also what you need to write down to get all 5 marks. Right so over to here where I’ve got the calculator,
I need to be in the right mode first of all so I’m going to select STATS, so I need to
press 2 in the main menu. That brings up this screen here, which has got various spaces
for entering lists of values. Now, I’m going to be using List 1 to hold my X values and
I’m going to be using List 2 to hold my F values. OK, so all I need to do now is to
type those into the calculator, so in List 1 I’m putting in my x values, so 4, 5, 6,
7, 8, and 9. We use the right arrow to go to the next column and type in all my frequencies,
so 2, 7, 9, 11, 2, and 5. Now once I’ve got the data in, I need to choose
the right thing on the list of options here in order to find standard deviation. There’s
actually quite a lot of things your calculator can do with these numbers and I’m going to
be using the CALC option here, which is F2. When I press that, it gives me an option to
do calculations with one variable or with two variables. The two variable one would
be things like bivariate data, if you are looking for linear regression, which I’m going
to show you in a different video clip. But for now I’m going to be using one variable
calculations. Now before I do that, I need to check that
the calculator is set up correctly, so in the set area here I’m just going to double
check that the calculator is looking at the lists in the right way. Now, to do one variable
calculations with a frequency table, and so my x values are going to be in list 1 and
my F values are going to be in List 2. At the moment, the calculator is set up for all
the frequencies being 1, so it’s set up for a 1 list of data. So I need to change that
so it looks into list 2 and reads out the frequencies, so list 1 will by my X values
and List 2 will be my frequencies. Okay, done. So I can exit that and then I’m going to select
one variable calculations. Now, the calculator then churns out lots and
lots of different calculations. It does all sorts of things. Look down here, it’s got
quartiles and medians and modes etc. Now I’m not really interested in those in this particular
question. I’m interested in these values at the top. X bar is actually the mean, so that’s
the value I’m going to write down over there. Then I’ve got all my various totals down here
and my values for standard deviation. Now I need to write those all down. The first value I’m going to write down is
sigma f, the sum of the frequencies. Now on the graphical calculator that’s given by n,
the number of elements. So it’s 36. So next to that sigma f I’ going to write down 36. Now sigma fx is given by this one here, sigma
x, equal to 235. So that’s my value there, 235. Sigma fx squared is this one here, 1603.
1 6 0 3. Now I don’t need to do any calculating for the mean, that’s already given. 6.53 to
3 significant figures. So lets just write that one down. Now, I suppose I could just write down standard
deviation as well, but I want to show my method to make sure I get all those 5 marks for this
question, so I’m just going to sub the 3 values in which I’ve already written down into the
formula just to make sure I’ve got enough method to gain all the marks. So 1 6 0 3 divided
by sigma f, which is 36, minus the square of the mean, 6.53 squared. Now I don’t need to type this into my calculator
because it’s already been done for me. Now the calculator actually generates 2 values
for standard deviation. This is one for a population, and this is one for a sample.
But you don’t need to know much about what those are at the moment. At A level we just
use that top one. So this is the one we want, 1.38 is the value I’m going to write down.
1 point 3 8 to 3 significant figures. And that’s it. We didn’t really have to do
any complicated calculating. All I needed to do was to be able to type this table in
to the calculator and to be able to interpret this list of results that it gives me. And
that’s it. ## Check out MrTompkinsEdTech Channel for more Maths / Stats videos on the Casio Graphical Calc ##

– WE WANT TO EVALUATE
ARCCOTANGENT OF -3.6, WHICH MEANS WE WANT TO DETERMINE
AN ANGLE THAT HAS A COTANGENT
FUNCTION VALUE OF -3.6/1. NOW, THERE ARE AN INFINITE
NUMBER OF ANGLES THAT HAVE A COTANGENT
FUNCTION VALUE OF -3.6, BUT THE OUTPUT OR RANGE
FOR ARCCOTANGENT IS ON THE OPEN INTERVAL FROM
0 TO PI RADIANS AS STATED HERE. SO OUR ANGLE, LET’S CALL IT
AN “A,” MUST HAVE A TERMINAL SIDE
IN THE FIRST OR SECOND QUADRANT. AND SINCE THE COTANGENT
FUNCTION VALUE IS NEGATIVE, ANGLE “A” MUST HAVE A TERMINAL
SIDE IN THE SECOND QUADRANT. BUT BECAUSE THIS COTANGENT
FUNCTION VALUE IS NOT GOING TO RETURN AN ANGLE
THAT HAS A NICE REFERENCE ANGLE WE’LL HAVE TO USE
THE CALCULATOR. AND WHEN USING THE CALCULATOR IT’S MORE CONVENIENT TO USE
OUR TANGENT RATHER THAN OUR COTANGENT. AND SINCE COTANGENT AND TANGENT
ARE RECIPROCAL FUNCTIONS, IF ANGLE “A” HAS A COTANGENT
FUNCTION VALUE OF -3.6, THEN WE CAN SAY THAT OUR
TANGENT, OR THE RECIPROCAL, OR -1 DIVIDED BY 3.6
WOULD RETURN AN ANGLE THAT HAS A COTANGENT
FUNCTION VALUE OF -3.6. HOWEVER, THE ONLY ISSUE
WITH THIS IS THAT THE OUTPUT OF ARCTANGENT
IS DIFFERENT FROM THE OUTPUT OF ARCCOTANGENT. NOTICE THAT THE OUTPUT OR RANGE
OF ARCTANGENT IS ON THE OPEN INTERVAL
FROM – PI/2 TO PI/2, WHICH MEANS THE TERMINAL SIDE
OF THE ANGLE WOULD BE INTO THE FIRST QUADRANT
OR FOURTH QUADRANT. AND BECAUSE THE TANGENT
FUNCTION VALUE IS NEGATIVE, OUR TANGENT OF -1 DIVIDED BY 3.6 IS GOING TO RETURN AN ANGLE
WITH A TERMINAL SIDE IN THE FOURTH QUADRANT OTHER THAN THE SECOND QUADRANT,
WHICH WE WANT FOR ANGLE “A”. SO LET’S GO AHEAD AND CALL THIS
ANGLE B, AND THEN WE CAN USE
THE REFERENCE ANGLE OF ANGLE B TO DETERMINE ANGLE “A”. SO WITH OUR CALCULATOR OUT,
LET’S CHECK OUR MODE. NOTICE HOW WE’RE IN DEGREE MODE,
SECOND TANGENT FOR ARCTANGENT. THEN WE’LL TYPE IN -1
DIVIDED BY 3.6. THIS TELLS US THAT ANGLE B
IS APPROXIMATELY -15.5 DEGREES, SO IT MIGHT LOOK
SOMETHING LIKE THIS. NOW, THIS ANGLE DOES HAVE
A COTANGENT FUNCTION VALUE OF -3.6, BUT THIS ANGLE IS NOT AN OUTPUT
FOR ARCCOTANGENT. BUT THIS DOES TELL US
THAT THE REFERENCE ANGLE IN THE SECOND QUADRANT WOULD HAVE TO BE APPROXIMATELY
15.5 DEGREES. SO ANGLE “A,”
THE ANGLE WE’RE LOOKING FOR, WOULD BE THE ANGLE THAT HAS
A TERMINAL SIDE HERE WITH A REFERENCE ANGLE
OF 15.5 DEGREES. SO ANGLE “A” HAS AN INITIAL SIDE
HERE AND A TERMINAL SIDE HERE. THIS IS OUR ANGLE “A”. SO ANGLE “A” WOULD HAVE TO BE EQUAL TO 180 DEGREES
– 15.5 DEGREES. SO ANGLE “A” IS APPROXIMATELY
164.5 DEGREES. NOW LET’S GO AHEAD AND DETERMINE
THE MEASURE OF ANGLE “A” IN RADIANS AS WELL. AND WE COULD JUST CONVERT
AND USE THE CALCULATOR. SO WE’LL PRESS THE MODE KEY,
SWITCH IT TO RADIANS. GO BACK TO THE HOME SCREEN AND WE’LL PRESS SECOND TANGENT
– 1 DIVIDED BY 3.6 AGAIN. SO THIS TELLS US THAT ANGLE B IS
THIS ANGLE HERE IS APPROXIMATELY
-0.2709 RADIANS, WHICH MEANS OUR REFERENCE ANGLE
THE MEASURE OF ANGLE “A” WOULD BE PI RADIANS – 0.2709, WHICH WOULD BE APPROXIMATELY
2.8707 RADIANS. SO FROM THIS EXAMPLE YOU CAN SEE
WE NEED TO EXTRA CAREFUL WHEN USING THE CALCULATOR TO DETERMINE SOME INVERSE TRIG
FUNCTION VALUES. I HOPE THIS WAS HELPFUL.

Hello everyone! This is a tutorial on how to find a
five number summary, mean and sample
standard deviation using your TI 83 Calculator. If you are not sure on how to put values into your
calculator then you can find a link to a video that
will show you how to do that in the description. Go ahead and pause the video and put these
values in your calculator. So once we have these values in our calculator
we will check and make sure they are correct. Then go to the home screen. 2nd>Mode. Now, we will use the 1 var stats function to find
the 5 number summary, mean, and sample
standard deviation. Hit the STAT Key. Located here(screen)… then go to the CALC
sub-menu. Notice there is a function called 1 var stat. This will tell us the 5-number summary, mean
and SD. Then put in what list your values are in…(L1) Push 2nd>1 You can also find that list by hitting 2nd>STAT,
then hitting enter on L1. Once you have L1 in place hit ENTER. So you can see there are a lot of different
statistics that I might want to know. Sample mean or average height of the students. Sample standard deviation Sx. Population standard deviation. These two values are different because they are
calculated using a different formula. Depending on whether you have a sample or a
population of values you will use the appropriate
statistic. We will assume this is a sample of students from our class. N is the number of values I have. Notice it says 12…that is correct. If I scroll down…whenever there is an up or down
arrow you can use your scrolling buttons to see
more information. You can see that it will tell me the 5 number
summary if I scroll down. OK Lets go to the home screen to see another way
to find these statistics. Lets say I would like to find each of these
statistics one at a time. Maybe the mean or minimum. Go to the LIST menu. And you can see there are a number of different
statistics that I might want to calculate. For instance, maybe I want to find the mean.
That is the third menu item. Push Enter on the
mean(3) in the menu. Then I put in L1. And then hit enter and it tells
me the mean. I can also add or subtract. with this number,
multiply, or divide. Lets say I wanted to multiply the mean by three
for some reason. Then I can take the mean of L1 and multiply by
3. Or I can do other fancy things. Like multiply by three then add 8 and then divide
by two. You can do lots of different things with this. The
calculator just reads it as a value. Once it performs this it is just another number. OK. Please post comments or questions in the

Hello and welcome to Mr Tompkins Ed Tech.
This is a follow up to my “Standard Deviation with a Casio Graphical Calculator” video.
I was asked by subscribers RAFA BEAUS IRANZO and BEN IRWIN if I could explain how we can
use the calculator to find Standard Deviation from a Grouped Frequency table containing
Continuous Data. Thank you for the suggestion, RAFA and BEN, I am very happy to oblige!
If you also have a question or suggestion for a future video, please do let me know
in the comments below, and I’ll see what I can do. If you subscribe and hit the notification
bell, you’ll be notified of future uploads. In this video i’ll be showing you how to use
a Casio Graphical Calculator to generate basic statistics for data presented in a grouped
frequency table, including mean, median, quartiles, standard deviation and variance.
Here is a typical A Level statistics S1 or IB math exam questions, taken from a past
paper. It is based on a grouped frequency table containing the guesses of a 40 people
on the length of a road. We need to find the mean and standard deviation of these guesses,
which is no problem at all for this Calculator. There is a function that will happily generate
these statistics and a whole lot more besides with just a few key presses.
So lets pull up the Calculator. From the main Menu, press “2” for STATS
mode. Lets clear out any pre-existing data by pressing “F6”, then “F4” for DELETE
ALL, and F1 to confirm for each of the columns containing data. Done The first column is for our L values but we
have a problem here that our table has ranges for these and the calculator only wants one
number. We are going to use the mid-value as an estimate for each, which we can find
by averaging the upper and lower class boundaries of each group. When calculating these, it
is important to first consider whether the data is discrete or continuous and how the
values were rounded up or down. Now the values of L represent distance, which is a continuous
quantity and we are told it has been rounded to the nearest km. So the first group 10-12
actually represents all values of L between 9.5 and 12.5 km. So the average of these is
9.5 + 12.5 divided by 2, which gives us 11. Now notice in this case we get the same result
as if we had just used 10 and 12, but this will not always be the case and you will need
to consider boundaries carefully whenever dealing with grouped data.
OK, applying the same logic to our other groups we get estimated values of L of 11, 14, 18,
and 25.5, which we can now type into the Calculator, along with the frequencies 1, 13, 20 and 6.
So the hard work done, all we need to do now is ask the calculator to show us the stats. Press “Calc”, and then press “F6”
to make sure the calculator is SET right for a frequency table. 1-Var frequency needs to
be set to “LIST2” so that the calculator uses these values rather than assume we only
have 1 of each value. That done, we can “EXIT” , and press “F1” for 1-variable calculations.
The calculator will now happily churns out lots of values for us, scrolling down we can
see min, median, mode, quartiles and max values, which will be very handy for other questions,
but for this one we need these values at the top of the list.
X bar is the mean, so that’s the value I’m going to write down over here. 17.65. Then
we’ve got all the various totals down here, including the values for standard deviation.
It would be nice if I could just write it down and collect all the marks, but this is
A level and we need to show a bit of method. The first value I’m going to write down is
sigma f, the sum of the frequencies. Now on the graphical calculator that’s given by n,
the number of elements. So sigma f is 40. Now sigma fx is given by the value below,
sigma x, equal to 706. I’ll also need Sigma fx squared, which is the next one down, 13050.5.
I want to show enough method to make sure I get all those marks for this question, so
I’m just going to sub the 3 values I’ve written down into the standard deviation formula.
So 13050.5 divided by sigma f, which is 40, minus the square of the mean, 17.65 squared.
No need to type this into my calculator because it’s already been done for me. The next value
in the list is Standard deviation, so can just write down this one as my answer. 3.84
to 3 significant figures. Now our values for mean and standard deviation
are only going to be estimates as we have used the mid values rather than the actual
guesses to calculate with, so lets write that down in a sentence.
Taking a quick look at the markscheme, we get a B1, or independent of method mark for
the correct midvalues, a method mark and an accuracy mark for finding the mean, an implied
method mark for the total, a method mark for the substitution and an accuracy mark our
answer rounded to an appropriate degree of accuracy. A final B1 mark for realising that
the use of mid values means these are estimates only So RAFA and BEN, I hope you found this video useful. Please keep the requests coming, subscribe,
and check back regularly for new videos. Thanks for watching and see you next time ## More videos on Statistics available from MrTompkinsEdTech Channel ##

When calculating standard deviation and
variance, it is much easier to do it on a calculator than it is by hand. I already
have some numbers in my calculator that I want to find the standard deviation
and variance for, and so I’m going to begin by first pressing the STAT button.
Next I press the over arrow to highlight CALC at the top of the screen and I’m going
to look for one variable stats and make sure it’s highlighted. Next I’m going to
press the ENTER button and again look for this summary on the screen. I’m going
to make sure that the list I want to find to the standard deviation and
variance for is showing here and I use the down arrow to highlight calculate
and then press Enter. So when looking for standard deviation
there are two options that will show up on your calculator, and they show as Sx
and sigma X. Sx is your sample standard deviation. Sigma x is your population
standard deviation. Your calculator will not show you variance, but you can
calculate variance from your two standard deviations. So to find variance
you take each of your standard deviation values and you square them. So to find
sample variance I’m going to take my sample standard deviation which is seven,
and square it. So as you can see all of that previous information disappears
and I’m just typing up here on the screen. So to finding variance I just
hit ENTER. Now you can either write those numbers down on a separate piece of
paper to know what you have or you can always go back to STAT, go over to CALC,
and go back through the screens to find a value for population standard deviation,
to then be able to calculate population variance. So we don’t need to take this
whole number you can round it off to say 6.599….6.6
wherever your instructor wants you to round it to. So you could use 6.6 and then square it. Hit ENTER for population variance. So this is how to
find standard deviation and variance in your graphing calculator.

Hello everyone, my name is Garrick with SIRS-E and I’m here to talk a little bit about UL and what UL actually is. As a purchaser or installer of LED lighting you may wonder what is UL? What does it even mean? and why does SIRS-E utilize it? Well UL, or Underwriters’ Laboratory is a non-profit organization That tests, audits and inspects the manufacturing process of many products throughout many industries. It’s not the only certification company out there but being founded in 1894, it’s definitely one of the most prestigious and well-known. In regards to its relationship with SIRS-E, we’re interested with the requirements for low-voltage luminaires such as our LED strips and the accessories that go along with them such as power supplies and controllers. So what does UL actually mean? It’s important to understand that UL is a safety standard that may or may not be required by certain state or city ordinances. While it’s an important standard, it’s imperative to understand that UL does not necessarily identify a product as a high quality product or even the fact that it even works. UL is only concerned with safety implications and that means you shouldn’t expect all UL products to be top notch. That still falls on the manufacturer and for us this is key. We think about quality and output. UL will take care of the safety standards. So what do we need to know from you? When contacting SIRS-E about an installation, we just need to know your requirements. Some installations may require no UL certifications, others just need to be recognized, listed, or a listed class 2 installation. Regardless of any of those factors, we can definitely help you out. Remember, if you have any questions you can leave your comments down below we’ll get back to you as soon as possible. Also you can look up our personal UL information on our resources tab at sirs-e.com. Also, don’t forget to like and subscribe, and thanks again for watching.

The next big thing when it comes to home entertainment
is 4K TVs. And they’re stupid. Now if you didn’t figure this out from my
self-driving cars video, I’m just taking a holy grail of reddit and deconstructing
it in order to talk about vision – and maybe flirt a little bit with color finally. 4K TVs will happen eventually, but they’re
kind of wasted on most people. So let’s get started. Now, this video is currently being filmed
in 1080p at 30 frames a second – actually 29.97 frames per second but… 30, okay? And this is pretty much the current standard
format for most media, including Youtube. So let’s step back in time a bit and see
how we got here. This is 480i. But this is clearly too small so let’s uh… There we go. If you’re older than 20, you should recognize
this. This is what home television was for most
of its history. Now, there were lower resolutions, but we
have to start somewhere okay? The resolution is 640 by 480, which is where
the 480 in 480i comes from, the vertical resolution… this becomes important later. But let’s talk about the I, this stands
for interlaced. There is a difference between the field rate
and the frame rate. The field rate or refresh rate is 60 Hz, while
the actual frame rate is still 30. So you’re getting half a frame, interlaced,
each time. It may not be obvious with this video, but
you’ve likely seen something like this in lower quality videos… this is called combing
and now you know why. This is also why old CRT monitors and TVs
would flicker or have that rolling bar when you filmed them, because the camera frame
rate and the screen frame rate didn’t match up. And this is the format which VHS tapes were
in. Home video and VHS tapes weren’t really
a thing until Top Gun in 1987. That was the “must have” VHS tape and
the one that basically started the whole home theater industry… that’s just a funny
side note re- actually, you know why? VHS tapes used to cost upwards of a hundred
dollars, but Top Gun brought the price way down by having a Diet Pepsi ad in the beginning… You remember the ad. Anyway, VHS was a horrible format. It was just a magnetic tape. Not only did it degrade over time, but it
also degraded with each viewing. So the hundredth time you watched it, it would
be noticeably worse than the first time. So it needed to be replaced. This is 480p, the format of DVDs, you probably
didn’t notice much of a difference though. DVDs are to VHS tapes what CDs were to Audio
cassettes. The only difference is that the storage medium
was far more durable and resistant to degradation and the p. That stands for progressive, which unlike
interlaced, means you’re getting a full frame every single time without and combing. Now, a common saying among the non-techno
elite is that porn decides what the next video format will be. And that’s only been true once, during the
VHS and Betamax war of the 80s. But ever since then, it’s been video games. Most peoples’ first DVD player was the Playstation
2… and the must-have DVD was the Matrix, which came out in 1999. Every single person in high school right now
was born after the Matrix came out. Feel old yet? So the transition from VHS to DVD was fairly
quick because it was necessary and film studios finally stopped releasing VHS tapes in 2006. That really feels like it should have been
longer ago. Anyway, by 2006, people were starting to transition
to… High Definition (HD). You’ve probably noticed that we’re in
widescreen now. This ratio is known as 16 by 9, as opposed
to 4 by 3 which is known as fullscreen. Remember when old movies would say “This
film has been modified from its original version. It has been formatted to fit this screen?” What they’re saying is that they cut the
sides off to make it 4 by 3. So widescreen is the actual movie, not – as
I stupidly thought when I was a kid – the movie with black bars on the top and bottom. So HD not only made the resolution better
by making it 1280 by 720, which is one and a half times the size of 480, but also standardized
widescreen… which is far more accurate to what you actually see since you have two horizontally
placed eyes, making your horizontal viewing angle almost double your vertical. 720p is kind of forgotten middle child because
it came out at the same time as 1080i, and very shortly after, 1080
p… also known as Full High Definition There, that’s more like what you’re used to I
hope. It’s 1.5 times the size of 720p, so 2 and
a quarter the size of of 480p, at 1920 by 1080, and still 30 frames a second. Much like in the 80s, from 2006 to 2008 was
the Bluray vs. HD-DVD war, spearheaded by the video game consoles, the Playstation 3
and the Xbox 360. They were both the pretty much the same format,
1080p, with slightly different compression. So they were only competing to see who could
get the most sales, which Bluray won partially because the Playstation 3 came with a bluray
player built-in, unlike the 360’s HD-DVD which you had to buy… separately… that
was so dumb. There were no “must-haves” or memorable
“firsts” when it came to Bluray like with the previous formats, but the first bluray
movies came out in June 2006. 50 First Dates, for f… So here we are, in the current mainstream
format. Why did I just talk you through the history
to the next formats, yet again spearheaded by the gaming consoles, the PS4 and Xbox One. Before we get into the resolution changes,
let’s talk about framerate. As I said, this video is being filmed and
shown to you in 30 frames per second or fps. But there’s been a recent shift to 60 frames
per second. Yeah, I know, we round up, I don’t know
why that is. Now, framerate is a sacred cow in the gaming
community and on reddit, and they will defend their framerate more angrily than the second
amendment people, so I have to tread lightly. Let me start this off by saying that the average
person watching my video, whether you’re a subscriber or you found this on reddit,
is not the average consumer. You’re probably an early-adopter… you
are the techno elite. Not the average consumer. Remember when you thought 3D TV, Google Glass,
and VR were going to be the next big thing? Pepperidge Farm remembers… Now… the human eye doesn’t see in frames
– you see pretty much continuously – But. Beyond a certain speed, things can move too
fast for you to notice. Now depending on the source, at that seems
to be about 45 to 72 frames per second. Let’s go with 72. That means, just sitting there on your couch
eating doritos, if something appears on screen for 1/72nd of a second, odds are you’ll
miss it. Unless you know where to look and you’re
waiting for it. That’s at rest though. Your perceived framerate changes based on
your arousal level. If you just went for a run, or are being chased
by a dinosaur, or more likely, you’re hopped up on caffeine, you can see up to about 120
frames per second. And if you’re a super human, like a fighter
pilot, or you’re on cocaine or something, you might be able to see up to 240, but nobody
has been able to do it reliably beyond that. If you still think you can, you belong in
a lab because you’re some sort of mutant. So again, you don’t really see in frames
per second, but if something appears and disappears above a certain frame rate, you probably won’t
notice. 30 frames a second was established as the
standard decades ago, and I’ll get to why in a moment. But 60 frames seems to be where economic use
of energy and human perception meet. PC Gaming has been at or above 60 frames a
second for decades, and most computer screens are 60 Hz, so they top out at 60 frames a
Hz screen well… I won’t ruin the illusion for you I guess. For a while after HD came out, they started
pushing different framerates. When we’re talking about screens, they call
them hertz, but hertz is framerate. First it was 60, then 120, and then 240…
and then they stopped because the average consumer was complaining. Why would that be if we don’t really see
in frames per second? Because of the Soap Opera Effect. The Soap Opera Effect is when things are too
crisp and too fluid for real life, giving it an eerie look and causing motion sickness. Move your hand in front of your face. There was a significant blur, wasn’t there? This isn’t set to film in 60fps so let me…
there we go. So the soap opera effect makes things look
like they’re moving in slow motion, but at regular speed. I know, it’s weird which is why it gives
people motion sickness. The Soap Opera Effect doesn’t affect video
games, because a) it’s not real life so nothing really looks strange, and b) they
program in motion blur. So they’ve kind of stopped with the 240
and are only pushing 120 and 60, 60 being the likely new standard. However, framerate isn’t uniform across
your entire field of vision, which I’ll get to in a moment. The next big format shift is to 4K or Ultra
HD, which is a stupid name by the way – it’s just something they came up with in a marketing
meeting to make it sound more epic. Remember the naming conventions from before? 480, 720, 1080, there’s a nice pattern going
there. But 4K is four times the size of 1080p, so
you would think it would be called 4X. But it’s only twice the width and height,
so if we go by the same naming convention, it’s 2160p. So where does 4K come from? The horizontal measurement, 3840, rounded
up… to 4k. If we go by that naming convention, regular
1080p is actually 2K. I told you it’s dumb. Anyway, HD was a huge jump from regular D.
Most people can easily tell the difference. But HD to 4K? Most people can’t. Again, you are not the average consumer. And remember, you’re usually sitting about
10 feet away from your TV, or at least you should be. Actually, the myth that if you sit too close
to the TV, you’ll damage your eyes, is kinda true, but not for the reasons you were told
as a kid. It has nothing to do with the flickering or
the pixels or anything. It has to do with the fact that you’re not
changing your depth perception or focal length any. While you’re watching TV or playing a game,
your brain is perceiving distance, but everything, whether it’s the guy in the background or
your own character, are the same distance away. So your eyes never really have to adjust and
they get strained and fatigued. You won’t really damage your eyes, but they
will hurt. This would happen whether you’re watching
TV or you go outside and stare at the same tree for three hours straight. Anyway, 4K is 3840 by 2160, which means there
are 8 million 294 thousand 400 pixels, or just 8.3 megapixels for short. For a 60 inch TV, that means an individual
pixel is a third of a millimeter wide. Put a dot on a piece of paper only a third
of a millimeter wide and then put it ten feet away. Okay you probably still see it because it’s
a black dot on a white piece of paper but… okay? You know what I’m getting at. But you know what? There’s been a single black pixel right
here for the least few seconds. Go back and watch it again, you probably didn’t
notice. And this is 1080p, do you really think you
would have seen it if it was a quarter the size? Now get this, there are 8.3 million pixels
on that TV…. And there are only 6 million cones in your
eye… Yeah. But that isn’t even the whole story because
each pixel is actually three pixels in one, red, green, and blue… I hope you know that those are the primary
colors of light. But we only think that because we’re human. If you were to ask an alien what the three
primary colors are, they might say “Three? Silly Human, there are fifteen!” Though that’s pretty unlikely because- wait,
this isn’t the color episode stop! Anyway, the cones in your eye are ONLY red,
green, OR blue. And while the ratio isn’t exactly a third,
if we matched them all up to make a pixel, that means there are only 2 million “pixels”
in your eye. Before you say anything, rods don’t matter,
if cones are the pixels of your eye, rods are the backlight – you can’t see with
only rods but… stop trying to sidetrack me! Anyway, cones aren’t evenly spread across
your retina. Cones are concentrated in an area called the
fovea, which is only a third of a millimeter wide in the center of your retina. So while you’re looking at this screen and
think you see this… you actually see this. Now you have to take into account the fact
that we’re squishing about 210 degrees of your visual field down to maybe 15. But I’m actually still being generous. Of your visual field, your focal area is only
about 1 degree wide. Hold out your hand and look at one fingernail
– the other fingernails aren’t in focus. So as you can – hey! My eyes are up here! Actually, sidenote, if you’re talking to
someone you have a crush on, watch their mouth while they’re talking, for some reason,
they’ll pick up on that and start to like you more. Just a little tip on how to get the ladies
from Knowing Better *The more you know* But since most of your cones are concentrated
in the fovea, that also means that as you get out to the periphery, there’s less color
perception. The fovea is also where you get the highest
framerate, by the way, as I mentioned earlier. It’s the most important part of your vision,
and it’s the only thing that’s really tested when we figure out if you have 20/20
vision. Another sidenote, there’s no such thing
as “perfect vision” What 20/20 means is that at 20 feet away, you can read what most
other people can read at 20 feet away. If you have 20/100 vision, that means while
you’re reading it from 20 feet away, the average person can see it from 100 feet away. You have bad vision. But it’s okay because we all kinda do. Because while we do have some of the best
general purpose vision in the animal kingdom, our eyes are really poorly designed. All of your cones and rods are on your retina
in the back of your eye, and all those cells need blood… guess where all the blood vessels
are… Yeah, in front of the retina. So at all times, you are looking through a
field of blood, which your brain usually filters out but looks something like this. But all of those blood vessels have to get
back out of your eye somehow… which they do through a hole in the retina. Which results in a blind spot. Close your left eye… actually, remind me
right eye on the cross to the left. And move either your head or your phone closer
or further away – once you hit the sweet spot, the circle will disappear. It will be different distance depending on
what size monitor you’re on, but if you’re watching this on a computer, it’s about
3 feet. Your brain fills in that spot with whatever
is surrounding it. It’s kind of cool when you think about it. So not only do you not see this, you see this…
but you also have this going on. And of course, that’s not the end of the
story, because if you close one – oh yeah. Okay. What do you see when you close one eye? If you think it’s this, you’re wrong. When you close your… left eye, your brain
receives a “no input” signal, and turns off all information coming from that retina. So you don’t see half-black, you see this. Don’t believe me? Close your left eye. Now cover your left eye. Now open it. See? There’s a huge difference. Kinda cool that your brain just shuts off
incoming information like that. Anyway, so again, you’re seeing this. With the addition of this fun mess… which
can be bigger or smaller depending on how lucky or unlucky you are. So you really think you need a massive TV
with pixels literally the size of dust mites with all of this going on? Again, 4k will happen, mostly because they’re
just going to stop making HDTVs, but not anytime soon. There’s virtually no content for 4k right
now. Anything before last year will never be in
true 4k because it wasn’t filmed in 4k. The current generation of bluray disc, the
triple layer, holds 125 gigabytes of data. Do you know how big a 90 minute 4k video is?
477 gigabytes. So okay, it probably won’t be on physical
media anytime soon. So streaming, obviously. Yeah, well, unless you live in a big city
and not somewhere rural or like, Australia, you- better ge- used to that happening a lot. The major hurdle for 4k right now is the file
size, it’s just too large. And there are virtually no games in 4k right
now because of how much processing power that would take. As of May 2017, only 0.82% of steam players
are even able to play in 4k… and Steam players are the PC Gaming elite… so yeah. And in terms of TVs, in 2016 only 25% of all
new TVs sold were 4k. If I were a betting man – which I am – I
would say that 4k is going to take another 5 to 10 years to catch on for the mainstream. Much like cars, most people don’t buy a
new TV until their current one breaks. 8k on the other hand, will never happen…
it’s just too much for too little payoff. If we look at video formats like soap. 480p, or DVD, is regular old soap. It was fine for most people for a long time,
and many people still use it. 1080p is a big antimicrobial step up, it’s
obviously better and if people can get it, they will. 4k is like, super mega antibacterial, kills
99.99% of everything soap. And 8k is massive overkill, 99.9999 – like
who cares, okay. There’s an upper limit to what is necessary,
and 8k has 16 times the pixel density as HD… that’s too much. That’s fives times as many pixels as cones
in your eye. You’re never going to get a TV with pixels
the size of atoms, and at a certain point, it’s just not an economical use of energy,
storage, or bandwidth. If you don’t have better than 20/20 vision,
this is lost on you, and most people don’t see or care about the difference. And if you don’t believe me, they still
make DVDs, and still sell them by the millions. Last week I posted a poll on twitter – shameless
plug to follow me on there – asking people if they were to buy a movie today what format
would they prefer. Not what could they afford, not what setup
do they have, which would they prefer. And here were the results. Again, my average subscriber is not the average
consumer, so if anything, this poll is skewed in 4k’s favor. Think of all the people out there who don’t