standupmaths - 2016-10-03
I look at the historical quirks which gave us TV at 29.97 frames per second. In North America at least. It's a comfortable 25 fps in Europe. More on that thing I mentioned at the end of the video here: https://www.patreon.com/standupmaths Here is the spherical video I was making with Henry Segerman which made me research NTSC frame rates in the first place: https://www.youtube.com/watch?v=Yp12c3-IL-I Yes, technically, if you divide 4,500,000 by 286 you get a horizontal frequency of 15,734.26573 lines per second. That matches a frame rate of 29.97002997002997… and so old TVs used 30/1.001 = 29.97002997002997… CORRECTIONS: - A lot of people pointing out that increasing the number of horizontal lines without increasing the bandwidth would be a loss of resolution. Which is a good point. Music by Howard Carter Design by Simon Wright MATT PARKER: Stand-up Mathematician Website: http://standupmaths.com/ Patreon: https://www.patreon.com/standupmaths Nerdy maths toys: http://mathsgear.co.uk/
Great explanation. Me and my 2.97 friends thoroughly enjoyed it.
What happened to the other0.03 friends?
Bryan Vas cannibalism
@Mormon Freegan r/cursedcomments
Early television engineers were damned smart. Make the best out of a crappy situation due to the limitations of physics and find a solution. And they did it by using their brains and education with good old pencil and paper. Hat off to them!
Yes...and today there are no limits. Every method and material imaginable can be accessed and all formulas have already been discovered and set-up. Scientists today just plug in some numbers and new cool thing comes out.
Today we don't need brains, education or pen and paper. We jus use...well idk magic or something because that's all that's left when you toss out brains, education and pen & paper.
I like to know how much thought went into this comment
Not meant in a mean way or anything but im just puzzled
@Euzifyy No, we got the Apollo program from those Nazis.
First is almost certainly not the best in consumer goods and almost anything else. I still don't know how we managed so many moon launches without a fatality in space.
And who supplied the radio transmitter that Watson-Watt used to demonstrate radar in 1935? The BBC of course. ;-)
Hats
Next, can you do a video on why hotdog packages don’t match the number of buns in bun packages? I imagine it has something to do with the different resonate frequencies of the two foods.
>29.97 fps
>inches, feet, yards, miles
>month/day/year
>fahrenheit
>handegg
UNITED STATES OF MERICUH
@minh make us
that's ok mario, no one's perfect. that's brave of you to admit it
xD
oh cmon mario we all know i can't be wrong, i'm garet. it's a curse really. ;0
How stupid people are. All those units you mentioned just like electron volt, astronomical units are all derived from SI units. And it is just for easy calculations of large numbers. When you say light year, it is the distance travelled by light in one year, so it is (3*10^8) *1 year METERS. 1ev is 1.9*10^-19 JOULES. They are all SI units and has a BASE 10. So we can easily convert from one unit to another
And for the temperature, I can really tell how it is by knowing the temperature in degrees. Almost everyone can do it and it is practical that water freezes at 0 and boils at 100. It is an easy reference to find anything between it
https://youtu.be/rGjU8W4JmDQ
Watch this video and pause at 2:06
That's a good explanation except for fact that it's not 100% technically accurate. 29.97fps * 525 lines * 286 is actually equal to 4,499,995.5. Although we nominally refer to the NTSC framerate as 29.97, that's actually just an aproximation. The true framerate is actually 30/1.001, or about 29.97002997002997... When you plug 30/1.001 into your equation, you get EXACTLY 4,500,000Hz.
r/iamverysmart
Well, thought exactly the same :D Also.. Japan has some kind of weird mixup, that they use an effective framerate of 23,976023... (24/1,001). I think to convert the 25FPS to 30FPS. Because in much material even today, they just double every forth frame, which would result in a framerate of 29.97... FPS technically, but not effectivly.
@SlideRSB Thank you! The video creator immediately went off on tangents about how CRTs work and scanlines, and bandwidth, all of which had ZERO to do with why they changed from 30 in the black-and-white system to 30/1.001 in the colour system.
@Bud The Cyborg Analogue video has always been hard for people. Every new "expert" screws up horribly :-D
Ok dork
Unfortunately, changing the number of horizontal lines in a North American TV picture from 525 to 625 would have destroyed backwards compatibility with the existing black and white sets.
Adrian Bergqvist - This is not the 1950's.
@Adrian Bergqvist We're talking about the 1950s, when electronics were very expensive. Being forced to buy new TV or converter box would've been quite a financial setback.
@Tiberian Fiend Exactly! That's like saying "we have just invented the electric car, so next year we are replacing all gas stations with charging stations and everyone has to buy a new car. And your old car is worthless so you can't even sell it.
People get upset when their stuff gets made redundant overnight.
Legacy compatibility was the major factor.
In Europe we just made it incompatible, and switched to PAL, a much better system designed with colour in place from the start - previous systems used various standards e.g. UK 405/25
"Almost noone would notice" - *b*oi they're switching to color television. Who the hell wouldn't notice that?
It's a parker square framerate.
"There is infinite many of me, that's pretty good value for money..." Some infinities are larger than others... I feel robbed! Where's my upgrade?
"Standards have to be continuous . . . for some definition of continuous."
Gotta remember that one.
Be careful and responsible: upvotes must stop at 29.970 for this video.
They did not just take 60 Hz to match the electricity outlet, since synchronization could be set to anything, they did it to avoid interference-flicker with studio lamps and lights that are also connected to 60 Hz outlets.
I'm pretty sure that most TVs had their electron beam deflected by the environmental 60Hz electromagnetic noise, this would cause the screen to move vertically at the beat frequency between 60Hz and vertical scan rate. That would be quite annoying though I'm guessing 29.97 is close enough that a movement that takes 30 seconds to complete would not be noticeable.
Can you tell me why they didn't just rectify 60hz AC into DC? Seems like a lot of trouble for something that has such a simple solution.
@CS Ghost Animation - Yes, Thomas Edison's plan of transmitting power as DC instead of AC would solve the problem. It would also create far bigger problems.
The problem is the current that's not inside your TV set. It creates a magnetic field that deflects the CRT electron beam. The frequency difference between the external magnetic field and the vertical scan rate is what you see as motion on the tube.
@CS Ghost Animation DC has no Hertz
@CS Ghost Animation They did, but the filtering of the ripple wasn't perfect. Plus they didn't use voltage regulation like we do today.
why the hell is this video 50fps
Its 49.9700748431454768900656320621434464722659695338458797890976400113456778766778335 FPS u mean
@whenwillmakeupagoodname - Yup.
The modern European standard for electrical appliances is that they must handle 230V, with a margin of (I think) 10% either way. The situation before that was that the UK specified 240V, plus or minus 5%, and most of mainland Europe had 220V, plus or minus... whatever it was, bit probably also around 5%. Manufacturers found it easier to build equipment that could handle both ranges, rather than have to ship separate ones, and eventually then the standard for what any electrical item sold in Europe should be able to hanld was unified... But in fact mainly Europe's generators are still churning out (plus or vinus variations due to loading) 220V, while ours are still producing 240V (on a good day with a fair tail-wind). =;o}
More recently still, very clever power supplies have been developed that can auto-switch between the 230-ish range of Europe and the 120-ish range of other places, without either overheating or sacrificing efficiency. Designing things to run on specific supply voltages is becoming a thing of the past, except for the cheapest and most basic items (e.g. light bulbs).
@therealpbristow yeah, but in rural areas you can have the voltage dip below the spec or go far beyond it, especially during storms when trees and branches touch the land lines or when everyone suddenly turns on the heaters, and then the difference between 220 and 240 starts to really matter. Meaning manufacturers are forced to support much, MUCH larger tolerances if they don't want their devices fried en masse with subsequent warranty/customer service headaches.
This isn't really related to switching between 110 and 230, even the most universal and smart devices usually don't support voltages around 140-160 volts - where it's too far from the base voltage, but too close to switch.
I cannot resist anything below 50.000075 FPS .he should really make a updated version
@marzcorp Not PAL, video on computers is progressively scanned, so this is 50p, which is technically (sort of but not really) the same visual frame rate as PAL, as PAL is 25 fps at 2 fields = 50 fields. Interlaced footage at 25fps gives roughly the same visual sensation of motion as progressive at 50fps. But its not PAL, PAL is only for analog broadcast and reproduction.
Always knew NTSC as "Never Twice the Same Color"... must be my european PALs that taught me this ;-]
As a curiosity, Brazil used a NTSC-PAL hybrid called PAL-M, which featured 525 lines, exact 30 fps, and the PAL color encoding scheme with almost the same chroma carrier frequency as NTSC.
Exactly! It would be great if Matt made a video about it. PAL-M merged 30 FPS with perfect colour reproduction.
This was explained beautifully; I understood everything he said. Well done!
The BIG MYSTERY is why, despite:
• The death of CRTs
• The death of NTSC
• The death of analogue broadcasting
• The death of "standard definition" video
• The introduction of 720p, 720i, 1080p, 1080i, 4K and 8K
• The death of VCRs
• The death of tape-based systems in video/TV production
...this ridiculous frame rate still exists. I beg EVERYONE in TV/video production, please ditch 29.97! It'd be exactly like a musician of today never recording a song over 4.5 minutes because otherwise it wouldn't fit on a 7" 45rpm single!
"What the hell am I looking at!?" "When does this happen in the movie"
Something to note is that while NTSC is 525 lines, only 486 lines were actually used to visually show the image. The other 26 lines were used for vertical synchronization and retrace. Thats why SD digital is 480p, as thats equal to the actual visual representation of NTSC. PAL was about 600 lines of visible footage, so if you ever have on your hands a master tape of a European TV show, from BetaCam or something else, it makes more sense to up-convert it to 4:3 720p HD, or else you will be losing a bunch of quality.
Real SD digital is 486. DV is 480.
I failed to obtain an idea of what the young man was speaking about
I love how you used an altered CRT to present your points visually as opposed to mainly graphics in post-production. You really don't see this amount of creativity on a regular basis.
And im watching this on my 144 fps gaming monitor.
@yotubewatcherhalo console gaming is better than PC gaming
Human eyes can only see 29.97 fps.
yet this video is 30fps
@gigi gigiotto and u get screen tearing and your monitor still can only display 60 frames per second. vsync just means ur gpu waits for the monitor to finish displaying frames before loading the rest of the frames, where as with it off it skips frames etc.
@Olterior i know i'm not stupid :) but if you disable vsync you will improve latency
Hmm. I always thought NTSC stood for "Never Twice Same Color"
4:45 "I don't understound how that works."
The problem is that this should have fixed with ATSC, by using a 30FPS frame rate and converters to analogue would keep a 1 frame buffer, dropping that frame after 99 to resync to the TV.
I always assumed it was a rounding problem when converting from imperial time to metric time.
@Jim DeCamp "Transmission loss inside a building is negligible. Conductors are sized to control heat loss, more from fire concerns than economic."
Well, I sure appreciate your tenacity. ^^
Let me preface the following calculations with: I agree that the fire hazard is the #1 concern by far.
So here's some more electrical data: A typical European 230V wall plug uses 2.5mm^2 wires and may be fused (according to spec) to 16A (max. wire length about 28m). An American 120V[1] wall plug with 14 gauge wire (corresponds to 2.08mm^2) may be fused to 15A. Yes, that's almost the same amperage, and they (to me) surprisingly use less copper in this case (12 gauge, rated to 20A, is also used and requires more copper, see below). BUT, because of the lower voltage, the maximum power rating does come down to about a half (since power = voltage * current). Here's a quick summary:
– 14 gauge: 17% less copper, 51% less max. power (than 2.5mm^2 @ 230V)
– 12 gauge: 20% more copper, 35% less max. power
Again, I was admittedly surprised that American electrical wires are not necessarily thicker, but instead have a significantly lower power rating even when they are.
Next, I'll calculate thermal losses. Let's use a power that works under both limits, e.g. a 1600W electric kettle (or do you say water boiler?), and 10m of cable (that's about 33 ft). For fairness, let's assume 12 gauge wire in the US setup, which has about 3mm^2. Sorry about the metric units, but I find them much more convenient for physical calculations. This gives about 115mΩ (US) and 138mΩ (European) for the two wires of 10m each (phase and neutral) based on the specific resistance of copper. In the US, the kettle needs 13.3A for full power. P=I^2 * R, doing this calculation for the wire resistance gives about 20W. In Europe, a kettle with the same power needs ca. 7.0A, and P=ca. 6.7W. As mentioned above, I disregard the voltage drop on the wires in the power calculation as a simplification, but, just for reference, at the given currents, it's about 1.53V and 0.96V rsp., which means I'd actually have to go a bit above both mentioned currents (and more in the US case) to arrive at an appliance power of 1600W.
Even 20W thermal loss compared to the 1600W for the appliance certainly isn't much from an economic perspective, the main issue is that any generated heat must be dissipated to prevent equipment damage (fire in the worst case). Unfortunately, the maximum thermal load that a building's cabling can handle depends on a variety of factors such as whether cables go through thermal insulation, the number of wires per cable, the materials used – and I'm getting a little exhausted as well. (We can safely assume that, for most installations, the safety margins may appear exaggerated.)
"The Eighth Air Force, Army Artillery Corps and Waffen SS Sappers pursued a very thorough programme of urban renewal in the years 1943-45."
3.6 million or 20% of German homes were destroyed in WWII, a large number undoubtedly, but how much "urban renewal" that alone has caused is up to debate especially given that the war is over 70 years ago as well.
[1] I switched to the actual voltages used nowadays since both the 110V and 220V numbers are rather outdated.
@TruthNerds
I congratulate you on winning the internet. As expected, Jim DeCamp wasn't available for a come back it seems.
Kaleb Bruwer but who says if the horse is fed properly? Is it an Indian or African elephant? What breed of horse?
CraftQueenJr depends on if you’re a dem or a repub. lol
@Jim DeCamp Screw that, in South Africa, we use a more efficient 240V :-D How about them Japanese, where half the island was 50Hz and half was 60Hz, yet their TV standard was NTSC like America. That I stil haven't figured out!
a schooming
love how he talks.
The problem with 25 fps is that it flickers like hell, specially in CRT monitors. It was impossible not to notice it back then.
Curiously enough, Telefunken developed the PAL-M back in the 70s. It has 60fps (not 59.97) and also features the phase alternating line (aka PAL) that made the European PAL famous for its color fidelity.
The system was only adopted by Brazil and worked pretty well.
Even older movies didn't scan so their was no flicker. Fps in the theater is the whole frame at once. You only have 1 line between frames that interrupts the image. You don't have half of the image being scanned in at once then the other half.
No, that's not right. You cannot show a frame in theatres for a complete 1/24th second, because the film stock had to be pulled in place and then advanced to the next frame. The film transport would cause immense vertical motion blur (for regular 35mm projection). Theatres always used rotating shutters to hide the film transport motion. That was also done with the cameras. To make this rotation smooth, each of the 24 frames was interrupted twice. During one of the interruptions the frame was transported. This resulted in 48Hz for 24 frames :)
Later projectors used higher speeds, such as 72Hz or 96Hz (probably why nobody noticed flickering in the last decades).
@samusthpf Yes, the film had to be continuously pulled through the gate, but a rotating prism was used to redirect the light at the same time, eliminating most of the motion blur you're talking about... But it could still only do that for about half of a frame period Eventually the prism rotates 'til it's almost edge-on to the film, and the picture breaks up, so of course a spinning shutter was still needed to blank the screen at that point.
Testing showed that blanking the screen twice per frame gave people fewer headaches than blanking it only once per frame. Nobody knew why at the time, but it turns out it's due to the details of the way the eye sends signals to the brain: The more frequent the flash rate of the image (and the shorter the flash), the fewer photoreceptors you have all trying to send new information to the brain at once, so less signal congestion.
(I once owned a really cheap-and-nasty 18fps cine projector that didn't use a shutter: It had a piston-like system that would yank the film foward by one whole frame as quickly as possible, then leave it stationary in the gate for as long as possible while it swung upward to re-engage the sprockets one frame further up. The wear on the sprocket holes was horrendous, and of course there was this ghostly vertical smear that constantly tracked any horizontal movements in the image!)
Also the conversion of film to NTSC was smooth using a 3:2 pulldown but PAL simple played 24 fps film at 25 fps which speeds up the movie by about 4%.
@therealpbristow I've only seen rotating prisms on film editing desks and high speed cameras.
600hz is best refresh rate :^)
because 24, 25, 30, 50, and 60 are common factors
of course if you want to watch the hobbit you would need 1200hz to stay compatible
but there is a new technology called variable refresh rate so my argument is obsolete... if you only watch 1 video source.
In that case a variable refresh rate of 24-120hz would be ideal
48fps is the smoothest frame rate from 24fps, though.
I want a 600 hz display to watch 24 fps, 25fps and 30 fps videos without stutter.
The 29.27 issue tho
It amazes me how perfectly the "NTSC" abbreviation can be interpreted as "Not The Smartest Choice".
That ending though :D
But that aside, great job seeing the beauty in math and making it interesting. /subbed
Matt's wrong about what NTSC stands for. It's actually "Never The Same Color" because images looked wildly different from display to display and no two ever looked the same.
I have to know...how did he edit in his scanning line effect on the TV set using his live camera shot?
Because the TV screen was the live camera shot, it doesn't seem possible to produce this effect in post editing.
Any ideas??
1:30
12:37 No, I'm just procrastinating, thanks though.
NTSC stood for Never Twice the Same Color.
SECAM was System Essentially Contrary to the American Method
PAL is Perfection At Last
Ha-ha, I just posted the Never Twice the Same Color comment before I read yours.
HA! I'd never heard the SECAM one before. =:oD
and framerate*horizontal lines=frequency of that high-pitched noise
whoa, this guy's accent is so sexy. when he announced "COLOUR!" i gasped. so delicious.
also: cool animations! i loved this "guy talking in front of retro-looking animations on a tv screen" look; didn't get boring for any of the video!
It's called 0.1% "pull down"
10:50, well said. Thank you for your content.
Thing is, NTSC never used "line-by-line phase reversal", which was at the heart of PAL.
I always thought ntsc was a bit laggy compared to PAL, when I started watching anime in 2007, fansubs were from japan tv in 60hz ntsc and it was 23.98 fps 480i via Xvid and I used to watch tv at 50hz 25 fps 576i. 29.97 seems shitty and americans used it a lot apparently, japan too but for live action, ntsc is so weird
I stopped the video when you said "announcement". Sorry mate.
in germany we got a quote for this: "never change a running system"
but in this case it would be like saying "never change a mistake that already exists"
The most amazing thing in this video was seeing a CRT television........
@Ertytheqwerty: COUGH COUGH, good CRT has even 160Hz and 0ms lag. BTW BenQ is a crap.
Csgo pros still use crt's because there are some rare'r ones that are so damn good for gaming to this day.
People have too much money nowadays..
+SaintedPlacebo. Many film graders still use CRTs, since Trinitron is still regarded as the standard for colour.
I always play NES, SNES and N64 games on a CRT television.
I refuse to play those consoles on modern flatscreen televisions, it never looks any good and the controllers always have delays and crap.
CRT is the way to go.
10:46 is almost the Futurama God quote: “when you do things right, people won’t be sure you’ve done anything at all.”
Another constraint on NTSC television was that the color signal had to be viewable on black and white TVs, which were the vast majority of receivers in use at the time. So they could not change the number of lines. Changing the frame rate by 0.1% was within the tolerance of what the existing receivers could accept. So it wasn't a bad choice, it was a very clever choice that met all constraints.
Far from dumping on the engineers of the 40s and 50s, I admire their ingenuity. Modern digital techniques are much easier and far less constrained by physical and mathematical laws.
13:34 Best fix technique ever. I still use it on almost everything. It's like magic.
The editing is outstanding! I would love to see the tech used.
NTSC= 'never the same color'
Great irony - line by line phase reversal is also known as Phase Alternating Line - its what makes PAL PAL, NTSC doesnt use it
An old joke that became obsolete in the late 60s when transistor TV sets came around. What is really funny, is that most of the people who make fun about the color problem NTSC system had in its early years, are from countries that back in those days did not even have color broadcasting.
Quite correct - im an Australian technician - we didnt adopt PAL til '75ish - even so the colour accuracy of PAL was just better unless you had some way to correct phase drift, it just stopped being green faces
Lol
"Never Twice Same Color"
Daren Wilson - 2016-10-08
So many weird standards in the U.S. Sometimes I wonder if a dozen eggs isn't really 11.951 of them.
Blue - 2020-01-22
@donkmeister I would argue that provided the metric system was used for height in north america more, people would have an easier time understanding it (and would probably express their height in centimetres, not metres).
Not to ignore your example - I agree with that, although one could argue that a half of beer means "half the usual amount", which just happens to be a pint whereever you ordered beer. Equally, if you asked for a half of beer somewhere where the usual amount of beer happened to be a litre, you'd be unlikely to get half a pint (You'd get half a litre.)
Blue - 2020-01-22
this is the funniest comment i've seen
just
ever
you win
congrats
ObiTrev - 2020-02-17
It would be 11.951 if we counted eggs by their circumference using the Metric system.
Xnoob Speakable - 2020-02-23
@MoViesDProductions I WILL FIND THAT AND TRY TO USE IT
ChrJahnsen - 2020-02-24
@Wintermute It's just that it's simply too much trouble to convert. Every American is used to those standards.