[timonoko]

Black&White-tv was almost HD, 625x625. Then they added 3Mhz color-carrier in 1966 and it was 300x300 with this color-furze on top. This sucked so much. There was nothing I wanted see in living color. Especially winter-sports were mostly BW.

I remember that color movies sucked also in 1950s. Technicolor has annoying fuzziness around objects. See Wizard of Oz.

[briantw]

You're confusing the analogue horizontal resolution, with the high bandwidth of up to 5 MHz, with the digital number of vertical lines, which is fixed at 625 per frame, or the low bandwidth of 15 625 lines per second. No amount of chroma noise will change the latter. And as for the former, the analogue horizontal resolution, the higest horizontal resolution you could get, even at 6 MHz bandwidth, would have been 380 analogue lines - nowhere near 625. So, that's 625 lines down, and that's fixed - you couldn't change it. And only about 380 across, and yes, that could be affected by noise, chroma subcarrier, etc.

And speaking of chroma subcarrier, yes, you will often see crappy chroma fuzz on a black-and-white image, but the reason for that is that the TV set did not have a chroma filter (exactly what they are talking about in this thread). In fact, as I'm answering that, I'm realising that THAT was probably the reason they had to filter out the colour - because it would look crappy on older black-and-white sets that did not have a chroma filter installed. Bingo!

But I have a couple of circuits from like 30 years ago that converted NTSC or PAL to RGB, and yes, they have the required filter, or you did indeed see the little blockies from NTSC or diagonal fringing on PAL colour transients.

Interesting discussion!

[avian]

> Black&White-tv was almost HD, 625x625. Then they added 3Mhz color-carrier in 1966 and it was 300x300

Maybe adding color did decrease the luma bandwidth and hence the horizontal resolution. I'm not sure about that. I think bw signals just used less bandwidth overall.

But in no way did color decrease the number of lines in the image. Those are defined by the scanning raster and remained the same in color and bw television.

[Taniwha]

It's more obvious in US NTSC that the PAL being discussed here .... essentially the colour subcarrier was put way out in the high freq part of the luma signal - display - anything with too high a bandwidth and it stomps on the colour - you've all seen this happen on analog TV ... and it has had profound effects on fashion .... let me explain ...

So what does "high frequency luma" mean? it means that the brightness of a signal horizontally along a line goes rapidly from dark to bright and back again - if that happens it stomps on the colour sub carrier and the colour goes wonky.

S-video is just a cable that puts the 2 signals on different wires so this doesn't happen.

So it turns out that the things that are the worst for this are things like checked or p;laid shirts/ties/dresses, tartans, houndstooth jackets etc etc - Think about what happened to fashion in the 70s/80s as colour TV became ubiquitous, people on TV started wearing solid colours, they didn't want to be the person who's whole body was a crawling mess - and people in the rest of the world started wearing the same sorts of styles - all those 50s/early 60s styles with checks and plaids you see on old game shows, all gone, not because of some big change in fashion - but because they could no longer be represented in popular culture.

[stuaxo]

I remember going to the US in 1998 and being shocked at how bad NTSC TV looked compared to PAL, the colours just looked wrong.

[lb1lf]

Back when I used to moonlight in video production, the quip was that NTSC was an acronym for 'Never Twice the Same Colour'.

The French SECAM system? 'Something Essentially Contrary to the American Method'

I'll lead myself out.

[cf100clunk]

SECAM was also jokingly called "Système Électronique pour Confondre les AMéricains"

[cf100clunk]

For technical reasons inherent in the chosen standard, NTSC TV sets required hue and color knobs, unlike PAL and SECAM. This effectively left it up to the consumer to adjust those values, with no accounting for variances in eyesight or taste. Unfortunately it meant that entire households had to endure the choices of whomever (Dad?) controlled the TV. On visits to others' homes it was painful to see how apallingly bad some peoples' preferences were. With PAL and SECAM the hue and colors were set to a standard, and that was that. Having said all that, the 29.97fps frame rate of NTSC was much easier on the eyes than the flickering 25fps of PAL and SECAM.

[Aloha]

NTSC adopted the color system it did because the cost of delay lines was considered to be too high, PAL also was more technically complex and probably would have delayed the adoption of Color TV, which was unacceptable to RCA.

The US oft has this problem, we tend to be early adopters of technology on a wide scale, so by the time a thing comes along that solves most of the inherent problems in the v1, we already have a wide scale implementation of the thing. This happened with TV color, phones (24 Channel T1 vs 32 channel E1 and aLaw/uLaw), credit cards (mag stripes), and all sorts of other things.

SECAM had some real advantages, but made working with composite signals hard, because of their FM nature. PAL and NTSC are reasonably close conceptually, and frankly so is PAL, you can easily encode PAL into SECAM, because it's mostly the composite signals that are different.

NTSC was originally 525 lines/60 fields per second (odd/even lines) giving an effective refresh of 30 fps, the 525 lines itself was dictated by our 6MHz channel width, and the field refresh by our 60Hz power. When they added color, they dropped the field refresh down to 59.97 to deal with a beat frequency issue between the color subcarrier and the audio subcarrier.

[Taniwha]

I'm guessing that watching PAL/SECAM requires slightly slower phosphors that NTSC and you'd see flicker on a modern computer monitor designed for 60-75 HZ ....

[briantw]

Did you try and adjust the hue? That was a necessary step in getting the colours right over in NTSC land. If you didn't adjust it, yes, you got pictures that were too magenta or too green. That said, I have an NTSC LaserDisc player still plugged in today, and if the hue is appropriately set, the colours are perfectly fine.

[Aloha]

NTSC and PAL had very very different color gamuts.

[Taniwha]

Yes - in the US HDTV was a revelation for many people because of the much larger colour gamut, it was just so much better, in Europe is was mostly just bigger

[avian]

None of this supports the parent's claim that TV went "from black&white 625x625 to color 300x300", which is just wrong on several levels.

[fortran77]

But there's some truth in this statement!

The "Luma" resolution is, in theory 625x625, but the "chroma" resolution is approximately 1/4 of that. That's OK, because the way our eyes work.

So "detail" remains at the 625x625 resolution, but the color information isn't that high. And our brains fill in the rest.

[tialaramex]

Digital video chroma sub-sampling literally has quarter chroma resolution in 4:2:0 video which is or at least was fairly common for live action stuff. It's obviously not going to be great for recording output from a computer, with sharp coloured edges, but live action scenes look fine.

I don't think anybody would claim that their 4:2:0 Blu ray has "low resolution" because it used chroma sub-sampling.

[timonoko]

> None of this supports the parent's claim that TV went "from black&white 625x625 to color 300x300", which is just wrong on several levels.

Obviously no one here has experienced pure crystal-clear BW-tv and what happened when they turned the color-carrier on. You had to adjust the focus so that horizontal resolution was below 320. And of course the vertical focus was similarly affected, as there was no separate screws for that.

[mhalle]

Crosstalk between luminance and chrominance signals are called dot crawl (chominance signal interfering with the luminance signal causing spatial artifacts) and chroma crawl (luminance signal stepping on the chrominance signal causing color artifacts).

I believe chroma crawl was generally more of an issue with NTSC, if the luminance signal wasn't sufficiently band limited.

[timonoko]

> But in no way did color decrease the number of lines in the image.

But it did. If you did not want to see the annoying 3Mhz color-carrier on your BW-TV, you had adjust the focus to 300 horizontal lines, which affected the vertical focus too.

[timonoko]

Had to correct numbers:

Super-good BW-TV was 625 x 625 x 25 = 10 Mhz. The color-carrier was 4.3 Mhz. So if you did not want to see the color-shit on your BW-TV, you had adjust the focus so that less than 625 x (4.3e6/(625 x 625 x 25)) == 275 horizontal lines were visible. TVs did not had separate adjustement for vertical focus. So all you really had was 270x270 TV.

Except of course there never was 10Mhz TV-channels. It was below 8 Mhz, which was needed for full color. So there was moment of time, when we could enjoy 8Mhz black and white for a year. Almost 600 horizontal lines. And then they turned the color on and party was over.

[adrian_b]

Actually in the 625-line TV standard there are only 576 visible lines.

The other lines are for the vertical retrace, when the video signal is blanked.

With square pixels, the B&W image would have been 576 x 768, which requires a 7.5 MHz analog video bandwidth (@ 50 Hz vertical & 15625 Hz horizontal frequencies).

Most 625-line B&W TV sets could display 576 x 768 images very well and some of the early personal computers with video outputs for TV used this format.

Nevertheless the broadcast TV signal was limited by a low-pass filter to lower horizontal resolutions, corresponding to 5 MHz analog video bandwidth in Western Europe and to 6 MHz analog video bandwidth in Eastern Europe. The reason was to provide space in the TV frequency channel for the audio signal, which used a carrier offset from the video carrier by 5.5 MHz in Western Europe and by 6.5 MHz in Eastern Europe.

So the broadcast B&W signal was worse than what the B&W TV sets could display, corresponding to 576 vertical pixels by about 510 to 620 horizontal pixels (depending on the country).

[hilbert42]

"Technicolor has annoying fuzziness around objects. See Wizard of Oz."

This happens with Technicolor only when it's processed badly and the registration isn't done with sufficient precision. I agree, this has happened from time to time.

Moreover, you also have to consider where the source material for the Technicolor process originated from. Tri-separated B&W negatives were used in the late 1930s, Wizard of Oz being one and the other major notable Gone With The Wind.

Prints from tri-separations can be quite excellent, in fact brilliant as the colour can be precisely adjusted. Also colour 'compromises' don't have to be made in the printing as is intrinsically the case with film that use colour couplers - Eastmancolor (Eastman color negative, its internegative and theatre release/print stock) to name just a few.

(Colour couplers in film emulsions are at best compromises as they have to be compatible with the processing chemistry and many of the best colour dyes and pigments are not. Processes that do not use colour couplers such as Kodachrome and Technicolor are much superior in this regard as stable dyes with the correct (or best) colour can be used. Colour couplers also lower the resolution of an emulsion although in many modern emulsions this isn't a significant problem.)

Nevertheless, if tri-separated B&W originals are used after being stored a long time then shrinkage differences in the three negatives can pose printing/registration issues.

It would be interesting to know the source of your Wizard of Oz, - as some years back the DVD version took this into account when the film was remastered. Every frame of the tri-separated B&W printing masters was resized to ensure its geometry was identical to all others. I've seen that remastered copy and its registration is excellent.

Incidentally, the very last version of the Technicolor processes of the 1950s was the best colour film system for movies ever devised before they went digital. However, one needs to bear in mind that many so-called Technicolor films are only hybrids, as they use Eastmancolor (or other) film stock for both the original source and for later dupes from earlier Technicolor theatre release prints. They, along with multigeneration copies, often create many issues including low (fuzzy) resolution and muddy cross-colour effects.

When making a claim like you have it's imperative you first check a film's manufacturing/printing methods. Tracing its manufacturing provenance is absolutely essential.

Edit: FYI, pre-WWII B&W film emulsions as used in the Wizard of Oz were never as grain-free or as sharp as modern-day equivalents are. You also need to ensure that you aren't drawing any comparison to these much newer products. The Technicolor process should not be blamed for limitations in the source material.