In article ,
John Walliker wrote:
On Tuesday, 9 February 2021 at 12:54:27 UTC, JohnP wrote:
I am not sure, but I THOUGHT that the replay head moved along with
the film, in jerks...

The sound head is a distance away from the fim gate and the head is
where the film is moving steadily through a capstan. There is a loop
in the film to absorb the jerking.
BBC Research Dept produced a progressive scan digital telecine machine
in the early 1970s which moved the film in a continuous motion
everywhere. There was a CCD line sensor feeding a digital field store to
generate an interlaced signal.

Yes - you could run it up from a still frame. Rank made a commercial
version. Only snag being the sound still took several seconds to become
stable.

--
*The severity of the itch is proportional to the reach *

Dave Plowman London SW
To e-mail, change noise into sound.

On 22/02/2021 11:05 am, Dave Plowman (News) wrote:
In article ,
JNugent wrote:
On 08/02/2021 02:18 pm, Dave Plowman (News) wrote:
In article ,
Chris J Dixon wrote:
Caecilius wrote:

On Sun, 07 Feb 2021 18:21:33 GMT, JohnP wrote:

A couple of things intrugue me about TV production:

[snip]

2. When cutting from one scene (in a drama) do they often cut to the new
sound - ahead of the picture? I suppose it is for some artistic reason -
but I can't appreciate it.

It's a video/film editing technique called a "J cut". See he
https://en.wikipedia.org/wiki/J_cut

I believe on traditional film, the sound signal is displaced from
the image, as it needs to run smoothly whilst the image jerks
through the gate.

Is it the case that a well-chosen film splice could have just the
effect described?

That would be more of a repair than edit. In the pro field, sound and
pictures have always been able to edit separately. Except, perhaps, the
early days of videotape.

As I understand it, editing of videotaped material has always involved
copying, rather than physical cutting and assembly.

Not so, although electronic editing (copying to another tape) was the
norm. But you could do it with a razor blade. Involved 'developing' the
tape with magnetic powder so you could see the pulses. But tape was very
expensive and cutting it made it no longer re-usable, so not used a great
deal except in a sort of emergency.

All interesting stuff.

Thanks.

On 22/02/2021 11:05, Dave Plowman (News) wrote:
Not so, although electronic editing (copying to another tape) was the
norm. But you could do it with a razor blade. Involved 'developing' the
tape with magnetic powder so you could see the pulses. But tape was very
expensive and cutting it made it no longer re-usable, so not used a great
deal except in a sort of emergency.

Many many years ago I got the loan of a little gadget for computer
tapes. It was basically a little jar with a flat bottom and a suspension
of iron oxide. It would settle quite nicely onto the old half-inch tapes.

That was when I was writing backup software for mainframes.

Andy