From Newsgroup: uk.tech.broadcast

Is there a name for the video effect in the music video for the Cliff
Richard song "Devil Woman"? -

https://www.youtube.com/watch?v=IgomTOOgl8M

How was it generated with the technology of the time (50 years ago)?
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From Newsgroup: uk.tech.broadcast

On 07/01/2026 01:22, Colin Earl wrote:

Is there a name for the video effect in the music video for the Cliff
Richard song "Devil Woman"? -

https://www.youtube.com/watch?v=IgomTOOgl8M

How was it generated with the technology of the time (50 years ago)?

Basically, by pointing a camera at the image on a screen and feeding
that back into the signal feeding the screen. If you look, you will see
that the definition gets worse as the image recedes, due to the extra generations. At the time, it really pushed the boundaries. In the '80s,
I found a video titler by Sony that could do the trick, and was being
chucked out by a studio. It used a mono camera to superimpose the titles
and even gave a choice of colours.
--
Tciao for Now!

John.

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From Newsgroup: uk.tech.broadcast

On Wed, 7 Jan 2026 07:54:29 +0000, John Williamson <johnwilliamson@btinternet.com> wrote:

On 07/01/2026 01:22, Colin Earl wrote:

Is there a name for the video effect in the music video for the Cliff
Richard song "Devil Woman"? -

https://www.youtube.com/watch?v=IgomTOOgl8M

How was it generated with the technology of the time (50 years ago)?

Basically, by pointing a camera at the image on a screen and feeding
that back into the signal feeding the screen. If you look, you will see
that the definition gets worse as the image recedes, due to the extra >generations. At the time, it really pushed the boundaries. In the '80s,
I found a video titler by Sony that could do the trick, and was being >chucked out by a studio. It used a mono camera to superimpose the titles
and even gave a choice of colours.

I thought of that trick, but couldn't get my head around how the
feedback is established. I have however since noticed that in the
shots where the number of images might smoothly transition from say 7
to 3, the width of the main image is constant. Is it a case of just
showing the performer in say the left quarter of the screen and
switching to the camera output for the rest? Or does the camera output
have to be delayed by (say) a quarter of a line to have the second
image in the right place when the transition is made?

Another well executed video is this one with lots of cleverly placed
chroma keying:
https://youtu.be/V5zcBJPSoqk?si=g3mINmOw03s-qvMg
It's not _perfect_ (e.g. the sax player's arm escapes the intended
frame at 0:51), but the planning must have been a real brain bender.
What's going on at the 2:30 mark? It looks like one camera's output is
scaled to fit the small keying area, but I wouldn't have thought the
70's technology would be capable.

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From Newsgroup: uk.tech.broadcast

On 07/01/2026 11:40, Colin Earl wrote:

On Wed, 7 Jan 2026 07:54:29 +0000, John Williamson <johnwilliamson@btinternet.com> wrote:

On 07/01/2026 01:22, Colin Earl wrote:

Is there a name for the video effect in the music video for the Cliff
Richard song "Devil Woman"? -

https://www.youtube.com/watch?v=IgomTOOgl8M

How was it generated with the technology of the time (50 years ago)?

Basically, by pointing a camera at the image on a screen and feeding
that back into the signal feeding the screen. If you look, you will see
that the definition gets worse as the image recedes, due to the extra
generations. At the time, it really pushed the boundaries. In the '80s,
I found a video titler by Sony that could do the trick, and was being
chucked out by a studio. It used a mono camera to superimpose the titles
and even gave a choice of colours.

I thought of that trick, but couldn't get my head around how the
feedback is established. I have however since noticed that in the
shots where the number of images might smoothly transition from say 7
to 3, the width of the main image is constant. Is it a case of just
showing the performer in say the left quarter of the screen and
switching to the camera output for the rest? Or does the camera output
have to be delayed by (say) a quarter of a line to have the second
image in the right place when the transition is made?

It is almost half a Century since I played with mine, and I didn't have
the facility to do that exact effect anyway, so I'm not sure of the
details. But it might have been as simple as a black surface in the
field of view of the camera taking the master image while using both
camera zooms.

Another well executed video is this one with lots of cleverly placed
chroma keying:
https://youtu.be/V5zcBJPSoqk?si=g3mINmOw03s-qvMg
It's not _perfect_ (e.g. the sax player's arm escapes the intended
frame at 0:51), but the planning must have been a real brain bender.
What's going on at the 2:30 mark? It looks like one camera's output is
scaled to fit the small keying area, but I wouldn't have thought the
70's technology would be capable.

That one is easy. In all the chromakey shots, the inserted camera zoom
and pan was used and synchronised with the pan and zoom on the view
which included the blue screen. There will have been a monitor showing
the output feed on the camera to let the operator control it as needed.
Very skilled boys playing with their (then) new toys. ;-)
--
Tciao for Now!

John.
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From Newsgroup: uk.tech.broadcast

On 07/01/2026 11:40, Colin Earl wrote:

It's not _perfect_ (e.g. the sax player's arm escapes the intended
frame at 0:51), but the planning must have been a real brain bender.
What's going on at the 2:30 mark? It looks like one camera's output is
scaled to fit the small keying area, but I wouldn't have thought the
70's technology would be capable.

Very impressive with the technology available at the time.

Notice at 2:26 a camera is pointed down at the ground, looking at a
mirror to give low-angle shots. I presume it needed a frame store to be
able to play in a signal that has its lines scanned from left to right,
and then be able to play them out in reverse order to give a mirror-image.


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From Newsgroup: uk.tech.broadcast

On 07/01/2026 14:31, NY wrote:

On 07/01/2026 11:40, Colin Earl wrote:

It's not _perfect_ (e.g. the sax player's arm escapes the intended
frame at 0:51), but the planning must have been a real brain bender.
What's going on at the 2:30 mark? It looks like one camera's output is
scaled to fit the small keying area, but I wouldn't have thought the
70's technology would be capable.

Very impressive with the technology available at the time.

Notice at 2:26 a camera is pointed down at the ground, looking at a
mirror to give low-angle shots. I presume it needed a frame store to be
able to play in a signal that has its lines scanned from left to right,
and then be able to play them out in reverse order to give a mirror-image.

Depending on the tech, it might have been easier to switch the scan
polarity? Did they have solid state cameras then or were they all 3 tubes??
--
Tciao for Now!

John.
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From Newsgroup: uk.tech.broadcast

On 07/01/2026 15:13, John Williamson wrote:

On 07/01/2026 14:31, NY wrote:

Notice at 2:26 a camera is pointed down at the ground, looking at a
mirror to give low-angle shots. I presume it needed a frame store to be
able to play in a signal that has its lines scanned from left to right,
and then be able to play them out in reverse order to give a mirror-
image.

Depending on the tech, it-a might have been easier to switch the scan polarity?-a Did they have solid state cameras then or were they all 3 tubes??

I wasn't sure how easy it was to switch scan polarity in a tube camera.
Is it just a case of swapping the connections on the horizontal
deflection coil for each of the tubes, or is there a lot more to it than
that?
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From Newsgroup: uk.tech.broadcast

On 2026/1/7 22:47:23, NY wrote:

On 07/01/2026 15:13, John Williamson wrote:

On 07/01/2026 14:31, NY wrote:

Notice at 2:26 a camera is pointed down at the ground, looking at a
mirror to give low-angle shots. I presume it needed a frame store to be
able to play in a signal that has its lines scanned from left to right,
and then be able to play them out in reverse order to give a mirror-
image.

Depending on the tech, it-a might have been easier to switch the scan
polarity?-a Did they have solid state cameras then or were they all 3
tubes??

I wasn't sure how easy it was to switch scan polarity in a tube camera.
Is it just a case of swapping the connections on the horizontal
deflection coil for each of the tubes, or is there a lot more to it than that?

Can't speak for cameras, but I once did it for a monitor - I can't
remember the details, but it was used by some apprentices with a camera,
and they had some reason to want to invert the image. Other than making
sure it was a break-before-make switch so that the drive was never even momentarily shorted, there was no problem.

I would imagine for a camera, though - quite apart from needing a very multi-pole switch to do three lots at once - it wouldn't surprise me at
all if reversing the scan direction caused alignment problems.
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G()ALIS-Ch++(p)Ar++T+H+Sh0!:`)DNAf

Worst programme ever made? I was in hospital once having a knee
operation and I watched a whole episode of "EastEnders". Ugh! I suppose
it's true to life. But so is diarrhoea - and I don't want to see that
on television. - Patrick Moore, in Radio Times 12-18 May 2007.
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From Newsgroup: uk.tech.broadcast

On 07/01/2026 22:47, NY wrote:

On 07/01/2026 15:13, John Williamson wrote:

On 07/01/2026 14:31, NY wrote:

Notice at 2:26 a camera is pointed down at the ground, looking at a
mirror to give low-angle shots. I presume it needed a frame store to be
able to play in a signal that has its lines scanned from left to right,
and then be able to play them out in reverse order to give a mirror-
image.

Depending on the tech, it might have been easier to switch the scan
polarity? Did they have solid state cameras then or were they all 3
tubes??

I wasn't sure how easy it was to switch scan polarity in a tube camera.
Is it just a case of swapping the connections on the horizontal
deflection coil for each of the tubes, or is there a lot more to it than that?

The alignments may alter when the polarity is switched, so you may get
colour fringes.
--
Tciao for Now!

John.
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From Newsgroup: uk.tech.broadcast

On Thu, 8 Jan 2026 05:25:42 +0000, "J. P. Gilliver" <G6JPG@255soft.uk>
wrote:

I wasn't sure how easy it was to switch scan polarity in a tube camera.
Is it just a case of swapping the connections on the horizontal
deflection coil for each of the tubes, or is there a lot more to it than
that?

Can't speak for cameras, but I once did it for a monitor - I can't
remember the details, but it was used by some apprentices with a camera,
and they had some reason to want to invert the image. Other than making
sure it was a break-before-make switch so that the drive was never even >momentarily shorted, there was no problem.

I would imagine for a camera, though - quite apart from needing a very >multi-pole switch to do three lots at once - it wouldn't surprise me at
all if reversing the scan direction caused alignment problems.

It did. It would have required a full scan lineup with a test chart to
make a colour camera usable after reversing the scans. Some of the old
image orthicon (monochrome) cameras had actually been modified to
include a switch to reverse the scans (inside of course, only
operable by engineers who would remember to switch off the beam
current first) but I never saw this on any colour camera.

Rod.
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From Newsgroup: uk.tech.broadcast

On 08/01/2026 07:27, John Williamson wrote:

The alignments may alter when the polarity is switched, so you may get colour fringes.

As an aside, I noticed when the Tour de Yorkshire came through my
village the other year, some of the motorbike cameras that "filmed" the cyclists had the cameraman sitting facing backwards (which is fairly
common) but others had the cameraman facing forwards (like the rider)
but using a mirror in front of the lens which must have required an
extra skill in composing the shot.

The difference between the two was very obvious: the mirror shots had
coloured fringes which were probably an *optical* artefact (chromatic aberration in the mirror) rather than an electronic registration given
that modern cameras use solid-state sensors which can be read out from
either direction with equal ease and which may have a single sensor
(like mobile phones and DSLRs) rather than three optically-aligned single-colour sensors; in either case, scanning in the opposite
direction would have been trivial.


I'm wondering with the floor mirror in TOTP, whether the image would
also have had to be scanned upside-down as well as left-to-right: my
brain hurts trying to work out whether that would have been needed. So
much easier nowadays when occasional low-angle shots could have been
done with a mini camera such as a GoPro at floor level - something that
was the stuff of dreams in the 1970s and 80s.
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From Newsgroup: uk.tech.broadcast

On 08/01/2026 15:38, NY wrote:
I'm wondering with the floor mirror in TOTP, whether the image would

also have had to be scanned upside-down as well as left-to-right: my
brain hurts trying to work out whether that would have been needed. So
much easier nowadays when occasional low-angle shots could have been
done with a mini camera such as a GoPro at floor level - something that
was the stuff of dreams in the 1970s and 80s.

The reversal is actually only in the horizontal direction, otherwise
shaving would be a lot more dangerous than it it. ;-)

It is actually a 3D reversal, with objects further away from the mirror
also looking further away in the refection, as if you had an
horizontally inverted 3D copy of the solid scene behind you hidden
behind the mirror.

Not used here, but if you make a periscope, using two mirrors, you get
an image which is the right way round. The mirror at low level is aimed
as needed, as is another in front of the lens, looking down at the other
one. This also works upside down for high level views where you can't
use a camera crane.

Just checked, and at 2:30 that is not a mirror, just a chromakey plate,
and the shot where it is used shows an eye level view in the "mirror",
not a reflection. The view in the "mirror" at 2:30 is a small part of
the main output.
--
Tciao for Now!

John.
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From Newsgroup: uk.tech.broadcast

Roderick Stewart <rjfs@escapetime.myzen.co.uk> wrote:

On Thu, 8 Jan 2026 05:25:42 +0000, "J. P. Gilliver" <G6JPG@255soft.uk>
wrote:

I wasn't sure how easy it was to switch scan polarity in a tube camera. >>> Is it just a case of swapping the connections on the horizontal
deflection coil for each of the tubes, or is there a lot more to it than >>> that?

Can't speak for cameras, but I once did it for a monitor - I can't
remember the details, but it was used by some apprentices with a camera,
and they had some reason to want to invert the image. Other than making
sure it was a break-before-make switch so that the drive was never even
momentarily shorted, there was no problem.

I would imagine for a camera, though - quite apart from needing a very
multi-pole switch to do three lots at once - it wouldn't surprise me at
all if reversing the scan direction caused alignment problems.

It did. It would have required a full scan lineup with a test chart to
make a colour camera usable after reversing the scans. Some of the old
image orthicon (monochrome) cameras had actually been modified to
include a switch to reverse the scans (inside of course, only
operable by engineers who would remember to switch off the beam
current first) but I never saw this on any colour camera.

Rod.

The Marconi MkVII has reverse switches for both H and V scans on the
camera control unit. It would need re-registering if you changed them.

Dave
--
This is a sig-free zone!
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