Why is TV 29.97 frames per second?

Would have been so much better had we not had the back ward compatibility requirement

I always thought NTSC meant Never Twice the Same Color

This video is great to watch 7 years later, so Matt surely did practice what he was preaching 😀

You ignored that the bandwitoh it self was the first limit, 625 lines means more data, and that would fit. In fact, PAL has more lines in Europe because it has less frames per second, in Brazil where PAL-M (PAL @ 30fps) was used, it has 525 lines

tldr: europeans smell bad

because 25

A slight clarification here - traditional analog television actually scans a complete new image per-field rather than per-frame, meaning that additional temporal information is sent with each pass of the raster beam from the top of the screen to the bottom.

As such, it’s approximately half the lines at double the rate - 262 lines at 59.94Hz, which would be assembled on the display side as a 525-line interlaced picture. (This trick is partially why retro video games display at ~240p at approximately 59.94Hz, which is often overclocked in emulation to 60Hz to sync with modern displays.)

This is also why PAL versions of retro video games are easier. The games run at 5/6 the speed and require 16.7% less reaction time. (Affected consoles include NES, SNES, N64, PS1, PS2, Sega Genesis, Sega Saturn, and more).

I was a video engineer throughout my career. The carry-forward of the weird 29.97 frames per second to digital monitors and video cards was infuriating. But the powers that be insisted on maintaining compatibility with 1960s video standards.

The constant behind those weird US frame rates is exactly 1.001. It is used everywhere to work out frame rates, clock rates, etc. For example: 30 frames per sec / 1.001 = 29.97 frames per sec.

excellent video

Fun fact: this difference between ntsc and pal is the reason video games ran ~16% slower on pal

Never the same colour. 😂 If only they had actually swapped the phase. Like pal did.

I love that fact you did the presentation side on an old CRT too

PAL owes its existence to NTSC. Saying NTSC is ridiculous downplays the fact that color was comparable with black and white standards. I respect your opinion but it lacks respect for the elegance of color solution.

nice video 👍

This is all well and good, but we now live in a digital age where TVs across the world are inter-compatible - why are we STILL shooting movies at 24fps?

It was somewhat ironic that the better resolution of PAL allowed widescreen broadcasts from the late 90s (pretty much every BBC show was widescreen from 2000) but when remastering old TV, most British shows were shot straight onto tape, with no more resolution possible, while the norm in American TV was 35mm film, hence a bunch of fancy HD remasters of shows that used to look pretty awful on TV.

ngl I zoned out after like 3 minutes

Awesome patreon support levels!! 🙂

if they change H lines, that mean everyone need to buy new TV?

NTSC had notoriously poor fidelity in color reproduction, the standard joke among electrical engineers was that NTSC stood for Never Twice the Same Color.

Standards have to be continuous - unless you’re Apple

I thought NTSC sands for Not the Same Color.

So how did the americans ensure the system clock frequency when it was no longer the same as the net frequency?

Well obviously they couldn't change anything else because of backward compatibility. Changing number of lines a little would work. But not by 15%. Some old TVs wouldn't manage to sync properly and / or to stretch the image on the screen properly. While changing FPS this little was 100% compatible.
That's beautiful about color TV. It's compatible both ways. Old BW TVs could without change receive and display newer color signal, and new color TVs could receive the old signal without special support for it, as it's just a subset of color signal.

With interlacing, the even rows don’t “fill in” a frame together with the odd rows, they are captured at a later moment in time. So moving objects are no longer in the same place on screen. That’s why deinterlacing isn’t trivial, you don’t have any full frames, only half frames all captured at different times.

You look just like John Cleese

NTSC also known as "Never Twice the Same Colour".

Incredible

One doesn't appreciate enough the impact of the IETF in the early internet. Up until then, there was Japan, EU and US, and most of their decisions were incompatible. Usually EU solutions were more elegant and US was... yeah, but no, because... no, really. Eg: metric versus imperial. This explanation is metric versus imperial all over it.

The US government mandated that the new color signals be compatible with the millions of existing black and white TVs in people's homes. That's why the resolution wasn't changed. It's all rather moot now.

retrocompatibility sucks!

But if the FPS was determined by the Hertz of the power supply, how were they able to change the FPS?

Actually it stands for "Never the Same Color"

PAL..Having the advantage as being tarted from scratch?...
The short answer is No..not the case.
625line 50hz 25fps was already a monochrome standard, used in most of Europe.
Post war...
625line was actually based on the then new 1940's USA 525 line 60hz 30fps monochrome standard.
(Being our electric is 50hz, we always had to go down the road of a lower 50hz 25fps).
This lesser frame rate, (and all things being sort of equal), gave us room to having 100 more lines per frame..). A sort of 'give & take' so to speak of.

PAL is really, ( as with its closely related cousin NTSC ) only a colour standard... made to be compatible with the existing black and white tvs already out there.
And weirdly:.........
Although at last, we had a monochrome picture standard at least, (at 625 line etc etc.)...within, there were a few different audio sub standards... within the standard...if you get what I mean

With this said, and along with the differing audio fiascos just mentioned , how we managed to avoid the need to make any weird frame rate adjustments, ( say 25.17 fps for example), when squeezing in colour,... I don't know.
It's all down to Maths, (or Math ), I guess...or luck maybe.

I know that this video is six years old and NTSC isn't online anymore but ask yourself this: Was NTSC a choice? It was the first colour broadcast standard on this planet. Of course there's going to be some kinks compared to PAL. PAL was made specifically to alleviate NTSC's bad stuff. And RCA was smart enough to do that, even though the colour isn't as good as PAL.

They should have reallocated the bandwidth. 2023 and we are still dealing with this shot! Mirrorless cameras still not doing True 30.0 fps.

Great explanation TKS

But: 525*29.97*286= 4499995.5

This hurts my head. I am stupid.

This hurts my head. I am stupid.

I could imagine that a major consideration was that old B/W TVs could just ignore the color signal and show a perfectly usable B/W picture using the same bandwidth. Changing the number of horizontal lines wouldn’t have accomplished that.

What a ripoff I can't believe color made my TV 0.1% slower smh

Electrons should be positive or electrical current should go the other way. The most stupid convention that has cost me a lot of points in tests.

That's the metric FPS vs the customary FPS.

Fun fact, a lot of the frequencies old analogue channels in the US used have been moved to other things like mobile networks. For example the Band 71 5G downlink on my phone is on 632 MHz (what was analogue tv channel 41) and the uplink is 678 MHz (channel 48). Apparently KSHB-TV (NBC affiliate) in Kansas City, KS used 41, and WAFF (also NBC) in Huntsville, AL used 48. Among others obviously, those were just what popped up first when googling 😆

The UK 625 line TV channel is 8MHz wide chosen in 1964. In North America, the TV channel is 6MHz wide chosen in 1936, first for 343 lines, then in 1938 441 lines and finally in 1941 525 lines. You could not increase in North America the number of lines without widening the channel! Furthermore, you render all the existing B&W TV's in service obsolete! That was the whole purpose of RCA's Compatible Color TV!!
As for the 4.5MHz, it is the spacing between the sound carrier and the video carrier. If it was widened by only a few hundred Hertz, yes the 30Hz frame rate could have remained. The problem was a invention in 1947 by Louis Parker called intercarrier sound. Intercarrier sound was the process of intentionally beating the sound carrier with the video carrier to create in the receiver a 4.5MHz Intermediate Frequency. Intercarrier. When NTSC color was developed in the early 1950's the engineers could not change the 4.5MHz sound video carrier spacing spacing otherwise the millions of intercarrier sets in service would have to be readjusted. So the only option left was to slightly change the scan rates.

And now none of these old Televisions are worth anything because they don't broadcast an Analog signal any more in the USA and you can't find Digital converters anmore.