On Sun, 26 Dec 2021 22:24:48 +0000, Scott
<newsgroups@gefion.myzen.co.uk> wrote:

>On Sun, 26 Dec 2021 16:40:27 -0000, "NY" <me@privacy.invalid> wrote:
>
>>"Max Demian" <max_demian@bigfoot.com> wrote in message
>>news:zq2dnQA2LJLYCFX8nZ2dnUU78T2dnZ2d@brightview.co.uk...
>>>> I am assuming that the monochrome 405 line signal was derived on the fly
>>>> from the 625 line material.
>>>
>>> In general, how did they do that?
>>
>>I've heard it said that some 405-line output was produced by pointing a 405
>>camera at a TV screen displaying the 625 version ;-) A TV version of film
>>recording.
>>
>>I wonder how it was done analogue-electronically, in the days before
>>digitisation and mathematical adding of varying proportions of corresponding
>>pixels on adjacent (*) 625 lines.
>>
>>ITN had DICE "Digital Intercontinental Conversion Equipment"
>>https://collection.sciencemuseumgroup.org.uk/objects/co34403/dice-digital-field-store-standards-converter
>>in 1973 so I imagine similar technology (without the extra hassle of
>>frame-rate interpolation) could have been used for 625->405 conversion.
>>
>>(*) Having de-interlaced so you were combing adjacent lines rather the
>>adjacent-odd or adjacent-even, and then re-interlaced afterwards.
>
>Why not use the archive film rather than the 625 line tape? How would
>the quality compare. (I realise this would not work for the news and
>other live broadcasts.)

Not every programme was made on film. If it was, then that could give
the best quality, but if the only surviving copy was a film recording
of something originated on videotape, then it would be monochrome, and
usually looked awful. Best quality is always derived from original
material, film or video - if it can be found.

Rod.

In article <pevisgdacig05oom4tb1lauqak6mgioemu@4ax.com>,
Roderick Stewart <rjfs@escapetime.myzen.co.uk> wrote:
> On Sun, 26 Dec 2021 22:24:48 +0000, Scott
> <newsgroups@gefion.myzen.co.uk> wrote:

> >On Sun, 26 Dec 2021 16:40:27 -0000, "NY" <me@privacy.invalid> wrote:
> >
> >>"Max Demian" <max_demian@bigfoot.com> wrote in message
> >>news:zq2dnQA2LJLYCFX8nZ2dnUU78T2dnZ2d@brightview.co.uk...
> >>>> I am assuming that the monochrome 405 line signal was derived on the fly
> >>>> from the 625 line material.
> >>>
> >>> In general, how did they do that?
> >>
> >>I've heard it said that some 405-line output was produced by pointing a 405
> >>camera at a TV screen displaying the 625 version ;-) A TV version of film
> >>recording.
> >>
> >>I wonder how it was done analogue-electronically, in the days before
> >>digitisation and mathematical adding of varying proportions of corresponding
> >>pixels on adjacent (*) 625 lines.
> >>
> >>ITN had DICE "Digital Intercontinental Conversion Equipment"
> >>https://collection.sciencemuseumgroup.org.uk/objects/co34403/dice-digital-field-store-standards-converter
> >>in 1973 so I imagine similar technology (without the extra hassle of
> >>frame-rate interpolation) could have been used for 625->405 conversion.
> >>
> >>(*) Having de-interlaced so you were combing adjacent lines rather the
> >>adjacent-odd or adjacent-even, and then re-interlaced afterwards.
> >
> >Why not use the archive film rather than the 625 line tape? How would
> >the quality compare. (I realise this would not work for the news and
> >other live broadcasts.)

> Not every programme was made on film.

If it was made in a TV Studio, it would be on video tape. Film copies were
made, in general, for the export market. Before the arrival of portable
recorders, outside (location) material was film which was played back into
the video recording.

> If it was, then that could give the best quality, but if the only
> surviving copy was a film recording of something originated on videotape,
> then it would be monochrome, and usually looked awful. Best quality is
> always derived from original material, film or video - if it can be
> found.

> Rod.

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

On 26/12/2021 17:10, charles wrote:
>
>> Did BBC2 get colour before the UHF versions of BBC1 and ITV? I thought
>> all channels were upgraded to colour at the same time for any given
>> transmitter.
> At source BBC2 (1 July 1967) got colour before BBC1/ITV (November 1969).
> The relay station building programmes was in full swing (70 sites per year)
> so some areas might well have got all 3 at the same time, if served by a
> relay.
>
Most of the 1960s built relays were quite late getting BBC 1 and ITV.

The first ever UHF relay Hertford, opened in Oct 1965 for BBC 2. BBC 1
was added April 71, ITV March 72

Sheffield/Crosspool opened with BBC 2 UHF Feb 1969 (just before Emley
collapsed !) BBC 1 UHF July 71, ITV UHF Jan 72, (so broadly the same
time that Hertford has added BBC 1/ITV)

Lancaster opened in Jan 72 for BBC 1/2, and ITV in Jun 72.

After mid 1972, then new relays seemed to have all three channels
launching at the same time.

In the early 70s the IBA had equipment supply problems for relays, with
the TWT based devices not working very well, which may explain why ITV
lagged behind BBC 1 introduction at most sites.

By about 1972, it was the same situation with new main UHF stations,
again BBC 1/ITV UHF lagged behind the 1960s BBC 2 transmitters up until
then.
Only four UHF stations carried BBC 1 and ITV from the launch of
625/colour for the two channels on Nov 15th 69.
CP, Sutton C, Winter H, and Emley (And Emley was a close call, because
of the collapse. Not even that week's YTV edition of the TV Times
mentioned colour (Unlike the other three regions)

On 27/12/2021 09:13 am, charles wrote:
> In article <pevisgdacig05oom4tb1lauqak6mgioemu@4ax.com>,
> Roderick Stewart <rjfs@escapetime.myzen.co.uk> wrote:
>> On Sun, 26 Dec 2021 22:24:48 +0000, Scott
>> <newsgroups@gefion.myzen.co.uk> wrote:
>
>>> On Sun, 26 Dec 2021 16:40:27 -0000, "NY" <me@privacy.invalid> wrote:
>>>
>>>> "Max Demian" <max_demian@bigfoot.com> wrote in message
>>>> news:zq2dnQA2LJLYCFX8nZ2dnUU78T2dnZ2d@brightview.co.uk...
>>>>>> I am assuming that the monochrome 405 line signal was derived on the fly
>>>>>> from the 625 line material.
>>>>>
>>>>> In general, how did they do that?
>>>>
>>>> I've heard it said that some 405-line output was produced by pointing a 405
>>>> camera at a TV screen displaying the 625 version ;-) A TV version of film
>>>> recording.
>>>>
>>>> I wonder how it was done analogue-electronically, in the days before
>>>> digitisation and mathematical adding of varying proportions of corresponding
>>>> pixels on adjacent (*) 625 lines.
>>>>
>>>> ITN had DICE "Digital Intercontinental Conversion Equipment"
>>>> https://collection.sciencemuseumgroup.org.uk/objects/co34403/dice-digital-field-store-standards-converter
>>>> in 1973 so I imagine similar technology (without the extra hassle of
>>>> frame-rate interpolation) could have been used for 625->405 conversion.
>>>>
>>>> (*) Having de-interlaced so you were combing adjacent lines rather the
>>>> adjacent-odd or adjacent-even, and then re-interlaced afterwards.
>>>
>>> Why not use the archive film rather than the 625 line tape? How would
>>> the quality compare. (I realise this would not work for the news and
>>> other live broadcasts.)
>
>> Not every programme was made on film.
>
> If it was made in a TV Studio, it would be on video tape. Film copies were
> made, in general, for the export market. Before the arrival of portable
> recorders, outside (location) material was film which was played back into
> the video recording.

Ah yes... Blakes 7 and their "teleported down to planet surface"
sequences. Planets always looked like gravel pits.
>
>> If it was, then that could give the best quality, but if the only
>> surviving copy was a film recording of something originated on videotape,
>> then it would be monochrome, and usually looked awful. Best quality is
>> always derived from original material, film or video - if it can be
>> found.
>
>> Rod.
>

On 26/12/2021 23:24, NY wrote:
> "R. Mark Clayton" <notyalckram@gmail.com> wrote in message
> news:783e60a2-2ee1-4816-8f2d-02ca35521dben@googlegroups.com...
>> On Friday, 24 December 2021 at 10:46:23 UTC, Scott wrote:
>>> On Fri, 24 Dec 2021 08:24:54 -0000, "Brian Gaff \(Sofa\)"
>>> <bri...@blueyonder.co.uk> wrote:
>>>
>>> >That would seem to be a daft thing to do if they had been recorded
>>> on >tape
>>> >to start with. Some very old recordings from that time will still
>>> play >as
>>> >long as somebody still has the working machines somewhere.
>>> > Brian
>>> I think it was the cost of the tape that was prohibitive.
>>
>> Sony did reel to reel recorders and I remember using one (probably CV
>> series with 1/2" tape) during training in 1978, but AIUI the BBC
>> mostly used Sony https://en.wikipedia.org/wiki/U-matic.
>
> I thought broadcasters tended to regard U-Matic as an ENG format for
> portable cameras and camcorders, but never used it for static
> stupid/location recording when the higher quality of 2" Quad or the
> various helical 1" formats was needed.

That's right U-Matic was only permitted by the BBC and IBA to be used
for news acquisition [1]. All other VT had to be Quad or 1 inch.

Even when component based BetaCam came out early 80s, its use was still
restricted to news. It wasn't until the late 80s when BetaSP (and MII)
came along that it was used for promos.
Full use of cassettte based tape for all programmes didn't happen until
the digital tape formats DigiBeta and D2 (Sony) and D3, and D5 (Panny)
came along in the early 90s.

[1] The only UK exception was Channel TV, who had special dispensation
to timeshift their mainland off-air recording of Crossroads from 5:20 to
6:30 using U-Matic (Because they simply couldn't afford to own or
operate Quad or 1 Inch VTRs)

On Sunday, 26 December 2021 at 17:14:17 UTC, charles wrote:
> In article <sqa5ts$thm$1...@dont-email.me>, NY <m...@privacy.invalid> wrote:
> > "Scott" <newsg...@gefion.myzen.co.uk> wrote in message

SNIP

>
> > Did BBC2 get colour before the UHF versions of BBC1 and ITV? I thought
> > all channels were upgraded to colour at the same time for any given
> > transmitter.
> At source BBC2 (1 July 1967) got colour before BBC1/ITV (November 1969).
> The relay station building programmes was in full swing (70 sites per year)
> so some areas might well have got all 3 at the same time, if served by a
> relay.

My recollection too - BBC2 also started in 625 lines.

Before our transmitter [Blackhill] switched my dad bought a Bush dual standard TV, only for me to discover when transmission started that there was no UHF tuner in it!

A very rich family were acquainted with (indoor swimming pool etc.) bought one of the first colour sets for IIRC £1,000 (~=£17k now) for which one could have purchased a decent car [of the time]

On Mon, 27 Dec 2021 04:51:51 -0800 (PST), "R. Mark Clayton"
<notyalckram@gmail.com> wrote:

>On Sunday, 26 December 2021 at 17:14:17 UTC, charles wrote:
>> In article <sqa5ts$thm$1...@dont-email.me>, NY <m...@privacy.invalid> wrote:
>> > "Scott" <newsg...@gefion.myzen.co.uk> wrote in message
>
>SNIP
>
>>
>> > Did BBC2 get colour before the UHF versions of BBC1 and ITV? I thought
>> > all channels were upgraded to colour at the same time for any given
>> > transmitter.
>> At source BBC2 (1 July 1967) got colour before BBC1/ITV (November 1969).
>> The relay station building programmes was in full swing (70 sites per year)
>> so some areas might well have got all 3 at the same time, if served by a
>> relay.
>
>My recollection too - BBC2 also started in 625 lines.
>
>Before our transmitter [Blackhill] switched my dad bought a Bush dual standard TV, only for me to discover when transmission started that there was no UHF tuner in it!
>
>A very rich family were acquainted with (indoor swimming pool etc.) bought one of the first colour sets for IIRC £1,000 (~=£17k now) for which one could have purchased a decent car [of the time]

Mark - were you interested in some piece of equipment earlier in the
year? I remember your contact but I cannot remember the outcome.
Scott

"Mark Carver" <mark.carver@invalid.invalid> wrote in message
news:j2tmvmFnnl5U1@mid.individual.net...
>> I thought broadcasters tended to regard U-Matic as an ENG format for
>> portable cameras and camcorders, but never used it for static
>> stupid/location recording when the higher quality of 2" Quad or the
>> various helical 1" formats was needed.

My brain said "studio". My fingers typed "stupid" ;-)

"JNugent" <jennings&co@fastmail.fm> wrote in message
news:j2sfolFgn5oU1@mid.individual.net...
> The lost & recovered 1970 edition didn't have an original (C) date (it
> wasn't the custom at the time), but added captions credited the
> restoration technical people and added a (C) date of MMXXI.

When did broadcasters start adding a copyright year (either in Arabic or
Roman numerals) in the end credits? Probably wasn't long after 1970, so the
M&W programmes probably only just missed having it.

On 27/12/2021 03:34 pm, NY wrote:

> "JNugent" <jennings&co@fastmail.fm> wrote:

>> The lost & recovered 1970 edition didn't have an original (C) date (it
>> wasn't the custom at the time), but added captions credited the
>> restoration technical people and added a (C) date of MMXXI.

> When did broadcasters start adding a copyright year (either in Arabic or
> Roman numerals) in the end credits? Probably wasn't long after 1970, so
> the M&W programmes probably only just missed having it.

I'm not sure when the inclusion of the (C) year became de rigeur.

There's no date on, for instance, Episode 1 of "Emmerdale Farm" (October
1972) and neither is it included on the first ep of Thames' "Harriet's
Back In Town" (same sort of date). Both were part of the clutch of new
ITV lunchtime soaps from late 1972 when broadcasting hour controls were
scrapped.

But the date is there by June 1974, when Thames showed the pilot for
"The Sweeney".

All of the above are present in complete form, on YouTube.

On Mon, 27 Dec 2021 17:04:11 +0000, JNugent <jennings&co@fastmail.fm>
wrote:

>On 27/12/2021 03:34 pm, NY wrote:
>
>> "JNugent" <jennings&co@fastmail.fm> wrote:
>
>>> The lost & recovered 1970 edition didn't have an original (C) date (it
>>> wasn't the custom at the time), but added captions credited the
>>> restoration technical people and added a (C) date of MMXXI.
>
>> When did broadcasters start adding a copyright year (either in Arabic or
>> Roman numerals) in the end credits? Probably wasn't long after 1970, so
>> the M&W programmes probably only just missed having it.
>
>I'm not sure when the inclusion of the (C) year became de rigeur.
>
>There's no date on, for instance, Episode 1 of "Emmerdale Farm" (October
>1972) and neither is it included on the first ep of Thames' "Harriet's
>Back In Town" (same sort of date). Both were part of the clutch of new
>ITV lunchtime soaps from late 1972 when broadcasting hour controls were
>scrapped.
>
>But the date is there by June 1974, when Thames showed the pilot for
>"The Sweeney".
>
>All of the above are present in complete form, on YouTube.

I know someone who played a part in Crossroads. I have gone through
many credits on YouTube episodes without success. I tried writing
to the company that now owns the rights (Local TV, I think). No
reply. I don't expect ITV plc would be interested. Any ideas how to
search further? Is there any public archive?

On 27/12/2021 17:12, Scott wrote:
> On Mon, 27 Dec 2021 17:04:11 +0000, JNugent <jennings&co@fastmail.fm>
> wrote:
>
>> On 27/12/2021 03:34 pm, NY wrote:
>>
>>> "JNugent" <jennings&co@fastmail.fm> wrote:
>>>> The lost & recovered 1970 edition didn't have an original (C) date (it
>>>> wasn't the custom at the time), but added captions credited the
>>>> restoration technical people and added a (C) date of MMXXI.
>>> When did broadcasters start adding a copyright year (either in Arabic or
>>> Roman numerals) in the end credits? Probably wasn't long after 1970, so
>>> the M&W programmes probably only just missed having it.
>> I'm not sure when the inclusion of the (C) year became de rigeur.
>>
>> There's no date on, for instance, Episode 1 of "Emmerdale Farm" (October
>> 1972) and neither is it included on the first ep of Thames' "Harriet's
>> Back In Town" (same sort of date). Both were part of the clutch of new
>> ITV lunchtime soaps from late 1972 when broadcasting hour controls were
>> scrapped.
>>
>> But the date is there by June 1974, when Thames showed the pilot for
>> "The Sweeney".
>>
>> All of the above are present in complete form, on YouTube.
> I know someone who played a part in Crossroads. I have gone through
> many credits on YouTube episodes without success. I tried writing
> to the company that now owns the rights (Local TV, I think). No
> reply. I don't expect ITV plc would be interested. Any ideas how to
> search further? Is there any public archive?
 The rights started off being owned by the makers, ATV/Central TV.
Central were bought by Carlton in the 90s, who then merged with Granada,
to form the present 'ITV Ltd' company. I think the archive for most of
the 'acquired' ITV programmes due to the 90s mergers and buy outs  is
now physically housed at YTV in Leeds

The local TV Birmingham TV station bought the rights to show the
episodes, but I think the actual rights still sit with ITV in Leeds

Start here
https://www.itvcontentdelivery.com/contact-us

"Mark Carver" <mark.carver@invalid.invalid> wrote in message
news:j2udn2Fs022U1@mid.individual.net...
> Start here
> https://www.itvcontentdelivery.com/contact-us

"Scott" <newsgroups@gefion.myzen.co.uk> wrote in message
news:2psjsglf9ia82j50b6r8q6th3b5kb90d6t@4ax.com...
> I know someone who played a part in Crossroads. I have gone through
> many credits on YouTube episodes without success. I tried writing
> to the company that now owns the rights (Local TV, I think). No
> reply. I don't expect ITV plc would be interested. Any ideas how to
> search further? Is there any public archive?

Have you looked at https://www.imdb.com/title/tt0057741/reference and/or
searched for their name on IMDB to see if they are listed and which episodes
they were in. That might help with tracking down recordings (Youtube or
official): date or episode number should help with searches.

On Mon, 27 Dec 2021 18:07:29 +0000, Mark Carver
<mark.carver@invalid.invalid> wrote:

>On 27/12/2021 17:12, Scott wrote:
>> On Mon, 27 Dec 2021 17:04:11 +0000, JNugent <jennings&co@fastmail.fm>
>> wrote:
>>
>>> On 27/12/2021 03:34 pm, NY wrote:
>>>
>>>> "JNugent" <jennings&co@fastmail.fm> wrote:
>>>>> The lost & recovered 1970 edition didn't have an original (C) date (it
>>>>> wasn't the custom at the time), but added captions credited the
>>>>> restoration technical people and added a (C) date of MMXXI.
>>>> When did broadcasters start adding a copyright year (either in Arabic or
>>>> Roman numerals) in the end credits? Probably wasn't long after 1970, so
>>>> the M&W programmes probably only just missed having it.
>>> I'm not sure when the inclusion of the (C) year became de rigeur.
>>>
>>> There's no date on, for instance, Episode 1 of "Emmerdale Farm" (October
>>> 1972) and neither is it included on the first ep of Thames' "Harriet's
>>> Back In Town" (same sort of date). Both were part of the clutch of new
>>> ITV lunchtime soaps from late 1972 when broadcasting hour controls were
>>> scrapped.
>>>
>>> But the date is there by June 1974, when Thames showed the pilot for
>>> "The Sweeney".
>>>
>>> All of the above are present in complete form, on YouTube.
>> I know someone who played a part in Crossroads. I have gone through
>> many credits on YouTube episodes without success. I tried writing
>> to the company that now owns the rights (Local TV, I think). No
>> reply. I don't expect ITV plc would be interested. Any ideas how to
>> search further? Is there any public archive?
>  The rights started off being owned by the makers, ATV/Central TV.
>Central were bought by Carlton in the 90s, who then merged with Granada,
>to form the present 'ITV Ltd' company. I think the archive for most of
>the 'acquired' ITV programmes due to the 90s mergers and buy outs  is
>now physically housed at YTV in Leeds
>
>The local TV Birmingham TV station bought the rights to show the
>episodes, but I think the actual rights still sit with ITV in Leeds
>
>Start here
>https://www.itvcontentdelivery.com/contact-us

Thanks very much to both of you. Two good leads.

On Mon, 27 Dec 2021 21:01:10 -0000, "NY" <me@privacy.invalid> wrote:

>"Scott" <newsgroups@gefion.myzen.co.uk> wrote in message
>news:2psjsglf9ia82j50b6r8q6th3b5kb90d6t@4ax.com...
>> I know someone who played a part in Crossroads. I have gone through
>> many credits on YouTube episodes without success. I tried writing
>> to the company that now owns the rights (Local TV, I think). No
>> reply. I don't expect ITV plc would be interested. Any ideas how to
>> search further? Is there any public archive?
>
>Have you looked at https://www.imdb.com/title/tt0057741/reference and/or
>searched for their name on IMDB to see if they are listed and which episodes
>they were in. That might help with tracking down recordings (Youtube or
>official): date or episode number should help with searches.

Thanks very much to both of you. Two good leads.

On 24/12/2021 00:16, JNugent wrote:
>
>> Did film recording of a programme that had filmed inserts take any
>> precautions to make sure that the change from one film frame to the
>> next in the film recording occurred in sync with the film insert as
>> it was originally telecined for the programme, rather than happening
>> to be one field adrift?
>
> I seem to remember mention of "station sync", which meant that all
> video being transmitted was locked to a station-wide time-signal,
> presumably to avoid the problem of which you speak.

It still is, it's the bedrock of all TV broadcast systems. Yes, it keeps
f1 and f2 in step for all sources locked to it. Up until the mid to late
60s, not all vision mixers (the equipment, not the operators of the same
name !) didn't always cut between sources during the vertical blanking
interval, and you'd so the image 'slice' at the cut point

On 29/12/2021 17:42, Mark Carver wrote:
> On 24/12/2021 00:16, JNugent wrote:
>>
>>> Did film recording of a programme that had filmed inserts take any
>>> precautions to make sure that the change from one film frame to the
>>> next in the film recording occurred in sync with the film insert as
>>> it was originally telecined for the programme, rather than happening
>>> to be one field adrift?
>>
>> I seem to remember mention of "station sync", which meant that all
>> video being transmitted was locked to a station-wide time-signal,
>> presumably to avoid the problem of which you speak.
>
> It still is, it's the bedrock of all TV broadcast systems. Yes, it keeps
> f1 and f2 in step for all sources locked to it. Up until the mid to late
> 60s, not all vision mixers (the equipment, not the operators of the same
> name !) didn't always cut between sources during the vertical blanking
> interval, and you'd so the image 'slice' at the cut point

Back long ago here in London in the 80s, it was entertaining watching
the sync lost and sound glitches, when they twice weekly switched
between the LWT and Thames companies that provided London ITV.

--
Adrian C

"Mark Carver" <mark.carver@invalid.invalid> wrote in message
news:j33l05FrsbtU1@mid.individual.net...
> On 24/12/2021 00:16, JNugent wrote:
>>
>>> Did film recording of a programme that had filmed inserts take any
>>> precautions to make sure that the change from one film frame to the next
>>> in the film recording occurred in sync with the film insert as it was
>>> originally telecined for the programme, rather than happening to be one
>>> field adrift?
>>
>> I seem to remember mention of "station sync", which meant that all video
>> being transmitted was locked to a station-wide time-signal, presumably to
>> avoid the problem of which you speak.
>
> It still is, it's the bedrock of all TV broadcast systems. Yes, it keeps
> f1 and f2 in step for all sources locked to it. Up until the mid to late
> 60s, not all vision mixers (the equipment, not the operators of the same
> name !) didn't always cut between sources during the vertical blanking
> interval, and you'd so the image 'slice' at the cut point.

I've seen a lot of older TV programmes repeated on Talking Pictures TV,
Drama, Yesterday where the digital TV frame consists of one field from one
source frame and one field from an adjacent frame. This is not apparent for
studio video, but it is very obvious for film if there is movement because
you get two fairly sharp images (sharper because of shorter shutter speed
than 1/25 sec) of adjacent film frames on each DVD frame, when you should
get both fields of the DVD showing different parts of the *same* film frame
and therefore no movement between fields of the same DVD frame.

The first series of Boon (so as late as 1986) had this problem on the DVD
set of the first series. When I later bought a box set of all seven series,
S1's film inserts were fine so someone had corrected the problem.

My analogue TV capture card randomly synchronises either correctly or
wrongly, so when I was copying programmes off VHS or other analogue source I
would check just after starting a recording to MPG, by single-stepping
through movement of a film insert; if it was there was a double image I'd
wind back and start again - rinse and repeat until it gets it right.

I've seen some recordings of very old TV programmes where the cuts between
studio cameras didn't look quite right, and single-stepping showed that the
cut had taken place during a field (not in VBI) so you got image slices.
There was one programme, broadcast from film recording, where I saw a cut
that had occurred during a line, so not even during line flyback. I was
rather surprised to learn that some early vision mixing equipment used
physical switches (relays) rather than transistor switches, so there was
plenty of opportunity for image corruption due to contact bounce, which
would be invisible if the cut occurred during VBI or line flyback but would
be very obvious at any other time.

"Adrian Caspersz" <email@here.invalid> wrote in message
news:j35iclF8chfU1@mid.individual.net...
> On 29/12/2021 17:42, Mark Carver wrote:
>> On 24/12/2021 00:16, JNugent wrote:
>>>
>>>> Did film recording of a programme that had filmed inserts take any
>>>> precautions to make sure that the change from one film frame to the
>>>> next in the film recording occurred in sync with the film insert as it
>>>> was originally telecined for the programme, rather than happening to be
>>>> one field adrift?
>>>
>>> I seem to remember mention of "station sync", which meant that all video
>>> being transmitted was locked to a station-wide time-signal, presumably
>>> to avoid the problem of which you speak.
>>
>> It still is, it's the bedrock of all TV broadcast systems. Yes, it keeps
>> f1 and f2 in step for all sources locked to it. Up until the mid to late
>> 60s, not all vision mixers (the equipment, not the operators of the same
>> name !) didn't always cut between sources during the vertical blanking
>> interval, and you'd so the image 'slice' at the cut point
>
> Back long ago here in London in the 80s, it was entertaining watching the
> sync lost and sound glitches, when they twice weekly switched between the
> LWT and Thames companies that provided London ITV.

I remember that - a picture that rolled or nudged, with coloured patches -
like a bad VHS edit.

Was there a fundamental reason why LWT and Thames couldn't synchronise their
feeds to the ITV network, either by feeding from a shared clock source, or
else by a suitable delay in the video (which is a lot easier once there is
digital framestore technology to do this, instead of having to use a
glass-block delay line). I presume the master clocks for Thames and LWT
would be at Euston and at Teddington respectively, so there isn't much
distance between them for signal propagation delays.

I remember that the changeover was more visible on some TVs than others,
depending on how long it took their line/frame sync oscillators to lock onto
a slightly early/late sync pulse. VHS recordings tended to magnify the
effect...

In article <sqk54i$p2j$1@dont-email.me>, NY <me@privacy.invalid> wrote:
> "Adrian Caspersz" <email@here.invalid> wrote in message
> news:j35iclF8chfU1@mid.individual.net...
> > On 29/12/2021 17:42, Mark Carver wrote:
> >> On 24/12/2021 00:16, JNugent wrote:
> >>>
> >>>> Did film recording of a programme that had filmed inserts take any
> >>>> precautions to make sure that the change from one film frame to the
> >>>> next in the film recording occurred in sync with the film insert as
> >>>> it was originally telecined for the programme, rather than
> >>>> happening to be one field adrift?
> >>>
> >>> I seem to remember mention of "station sync", which meant that all
> >>> video being transmitted was locked to a station-wide time-signal,
> >>> presumably to avoid the problem of which you speak.
> >>
> >> It still is, it's the bedrock of all TV broadcast systems. Yes, it
> >> keeps f1 and f2 in step for all sources locked to it. Up until the
> >> mid to late 60s, not all vision mixers (the equipment, not the
> >> operators of the same name !) didn't always cut between sources
> >> during the vertical blanking interval, and you'd so the image 'slice'
> >> at the cut point
> >
> > Back long ago here in London in the 80s, it was entertaining watching
> > the sync lost and sound glitches, when they twice weekly switched
> > between the LWT and Thames companies that provided London ITV.

> I remember that - a picture that rolled or nudged, with coloured patches
> - like a bad VHS edit.

> Was there a fundamental reason why LWT and Thames couldn't synchronise
> their feeds to the ITV network, either by feeding from a shared clock
> source, or else by a suitable delay in the video (which is a lot easier
> once there is digital framestore technology to do this, instead of
> having to use a glass-block delay line). I presume the master clocks for
> Thames and LWT would be at Euston and at Teddington respectively, so
> there isn't much distance between them for signal propagation delays.

Switching would be done by BT at the Tower. (Y-TOW). Euston is almost on
the doorstep, Teddington quite a few mile away.

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

charles <charles@candehope.me.uk> wrote:
> In article <sqk54i$p2j$1@dont-email.me>, NY <me@privacy.invalid> wrote:
>> "Adrian Caspersz" <email@here.invalid> wrote in message
>> news:j35iclF8chfU1@mid.individual.net...
>>> On 29/12/2021 17:42, Mark Carver wrote:
>>>> On 24/12/2021 00:16, JNugent wrote:
>>>>>
>>>>>> Did film recording of a programme that had filmed inserts take any
>>>>>> precautions to make sure that the change from one film frame to the
>>>>>> next in the film recording occurred in sync with the film insert as
>>>>>> it was originally telecined for the programme, rather than
>>>>>> happening to be one field adrift?
>>>>>
>>>>> I seem to remember mention of "station sync", which meant that all
>>>>> video being transmitted was locked to a station-wide time-signal,
>>>>> presumably to avoid the problem of which you speak.
>>>>
>>>> It still is, it's the bedrock of all TV broadcast systems. Yes, it
>>>> keeps f1 and f2 in step for all sources locked to it. Up until the
>>>> mid to late 60s, not all vision mixers (the equipment, not the
>>>> operators of the same name !) didn't always cut between sources
>>>> during the vertical blanking interval, and you'd so the image 'slice'
>>>> at the cut point
>>>
>>> Back long ago here in London in the 80s, it was entertaining watching
>>> the sync lost and sound glitches, when they twice weekly switched
>>> between the LWT and Thames companies that provided London ITV.
>
>> I remember that - a picture that rolled or nudged, with coloured patches
>> - like a bad VHS edit.
>
>> Was there a fundamental reason why LWT and Thames couldn't synchronise
>> their feeds to the ITV network, either by feeding from a shared clock
>> source, or else by a suitable delay in the video (which is a lot easier
>> once there is digital framestore technology to do this, instead of
>> having to use a glass-block delay line). I presume the master clocks for
>> Thames and LWT would be at Euston and at Teddington respectively, so
>> there isn't much distance between them for signal propagation delays.
>
> Switching would be done by BT at the Tower. (Y-TOW). Euston is almost on
> the doorstep, Teddington quite a few mile away.
>

We used to have a picture roll when East Midlands news switched in and out
of Breakfast.

On Thu, 30 Dec 2021 11:10:13 +0000, Adrian Caspersz
<email@here.invalid> wrote:
[snip]
>
>Back long ago here in London in the 80s, it was entertaining watching
>the sync lost and sound glitches, when they twice weekly switched
>between the LWT and Thames companies that provided London ITV.

Why would this be any more of an issue than switching between local
and network programmes at the individual francises? Surely STV in
particular would have lot of switching to do and I don't recall this
being problematic.

On 30/12/2021 11:28, NY wrote:
>
> Was there a fundamental reason why LWT and Thames couldn't synchronise
> their feeds to the ITV network, either by feeding from a shared clock
> source, or else by a suitable delay in the video (which is a lot
> easier once there is digital framestore technology to do this, instead
> of having to use a glass-block delay line). I presume the master
> clocks for Thames and LWT would be at Euston and at Teddington
> respectively, so there isn't much distance between them for signal
> propagation delays.
 You're thinking the wrong way. Thames and LWT were each running their
own Master SPGs, so were not in phase with each other. (Unless they were
both locked to a common reference such as the then NPL atomic clock then
they wouldn't have been in sync either)

As said, the 2 x1 switch between them and Crystal Palace was at the BT
Tower. The only way to have got a clean switch was for BT to have
'talked in' LWT to swing their SPG such that it was in phase with
Thames's (as compared at the BT Tower). Not worth the bother (and
expence) for a once per week switch.

Of course in later years the same thing also happened UK wide at 09:25
when each regional BT switching centre reconfigured the ITV distribution
network from being fed directly from TV-am, to back to having the
network 'tromboned' through each regional company.

BTW Thames's playout was Euston, LWT's was Kent House on The South Bank.
When Carlton took over the Mon-Friday franchise for London in 1993, they
collaborated with LWT, and shared the same playout control room at Kent
House, so the Friday 5:15 BT switch ceased.

On 30/12/2021 13:27, Scott wrote:
> On Thu, 30 Dec 2021 11:10:13 +0000, Adrian Caspersz
> <email@here.invalid> wrote:
> [snip]
>> Back long ago here in London in the 80s, it was entertaining watching
>> the sync lost and sound glitches, when they twice weekly switched
>> between the LWT and Thames companies that provided London ITV.
> Why would this be any more of an issue than switching between local
> and network programmes at the individual francises? Surely STV in
> particular would have lot of switching to do and I don't recall this
> being problematic.
See my other post.

As far as network programmes being in sync with local ITV company, that
was quite a different arrangement

Up until the early 80s, your local ITV station would in the 10-15
seconds or so before cutting to the network programme
adjust the phase  of the master SPG such that it drifted into sync with
the network feed. Normally done by adding or subtracting one line per field.
This had a drawback, that during this period any VTR or Telecine machine
servos would go bananas because they were receiving no standard syncs.

That's why the introduction into the programme was either a camera shot
of the announcer, or a caption (such as a clock)

When Frame Store Synchronisers appeared in the 80s, the ITV companies
adopted those, so whatever was stuffed into the input of a Frame Store
would be locked on its output to the local sync. That also liberated the
companies to be able use VT derived logos etc into programmes.