[Radium[_4_]]

re- and cross-posted to relevant NGs in hopes of receiving relevant
responses

Hi:

What audio artifacts are specific to the analog variable-density
optical audio tracks used in old B&W film - but don't occur in
magnetic audio tracks, in variable-area, in color tracks or digital
tracks?

Please respond with reasonable answers & keep out the jokes and
trivializations. I am really interested in this.


Thanks,

Radium

[Radium[_4_]]

On Jun 19, 4:14 am, Early Film wrote:
Radium asks:

What audio artifacts are specific to the analog variable-density
optical audio tracks used in old B&W film - but don't occur in
magnetic audio tracks, in variable-area, in color tracks or digital
tracks?

Absolutely none.

The difference is in degrees.

VD tracks on B&W stock, are just more sensitive to printing defects,
especially intermodulation distortion due to exposure errors, but they
did provide the best sound quality for any all-analog sound system when
done correctly.

Please note that almost all projection sound heads today are not
optimized for B&W VD tracks.

The only process more critical of correct exposure than VD on B&W was
VD on color stock. (Exception: IB Technicolor, where the track was B&W)

Color VD was used in the early days before Labs started applicating
tracks. I've seen applicated VD color tracks in 16mm, but they were too
exacting to do on a regular basis.

Earl.

Any artifacts caused by factors limited to the recording of the
negative?

[Early Film]

Radium asks:

Any artifacts caused by factors limited to the recording of the
negative?


I'll limit by reply to B&W VD and B&W VA neg to positive.

In recording, VA is more critical on exposure and gamma.

In printing from the negative, VD is more critical in exposure and gamma.

The artifacts are the same, it is just the degree with which they happen.

Different recording heads may produce different artifacts, but in many
cases the same head can record both VA and VD.

In color printing, I don't have enough experience to answer, since most
of the VD tracks for color that I've run across were done before my lab
time, although I did have to test to print a few old VD negatives on
modern color stock. (Lab time: 1963-1983 included recording, 1984 to
present QC)

Earl.

[peterh5322]

On 2007-06-20 03:33:41 -0700, Early Film said:

Different recording heads may produce different artifacts, but in many
cases the same head can record both VA and VD.

In one case the head is the same, the Maurer.

Now, the Western Electric RA-1231 used the same valve for VA as for VD,
but the valve's integral optical system was different, as one might
expect.

Also, the valve unit was different for 16mm as for 35mm, but the
principle was the same: same valve, 35/16mm; different optical systems:
35mm VA, 35mm VD, 16mm VA, 16mm VD; in one instantly interchangeable
unit.

The RA-1231 was a dual-gauge 35/16mm recorder, and was also the first
"Davis Loop" (AKA, "Davis tight loop") recorder.

The RA-1231 is easily the "exemplar" of all optical recorders. This
sixty-year-old machine is the basis of the Westrex/Nuoptix (now
Nuoptix/Photophone) stereo variable-area (S V-A) recorder, which, now,
records perhaps 99.44 percent of all optical tracks, produced
everywhere.

VD was abandoned primarily because of lab issues.

VA is now the de-facto standard not because of any presumed superiority
of VA over VD, but because 16mm is no longer an issue, in most cases,
and 35mm is now almost all stereo [ * ] , with the RA-1231's S V-A
valve being the only single-unit valve/optical system which is
implicitly time-aligned, and is eminently adaptable to stereo, two- or
four-channel.

[ * ] The RA-1231's dual-bilateral mono mode is simply a degenerate
case of its S V-A mode, but this fact was never fully appreciated by
industy researchers, although its capabilities were fully disclosed in
Frayne & Wolfe (1949), and elsewhere.

[Radium[_4_]]

On Jun 20, 9:14 am, peterh5322
wrote:
On 2007-06-20 03:33:41 -0700, Early Film said:

Different recording heads may produce different artifacts, but in many
cases the same head can record both VA and VD.

In one case the head is the same, the Maurer.

Now, the Western Electric RA-1231 used the same valve for VA as for VD,
but the valve's integral optical system was different, as one might
expect.

Also, the valve unit was different for 16mm as for 35mm, but the
principle was the same: same valve, 35/16mm; different optical systems:
35mm VA, 35mm VD, 16mm VA, 16mm VD; in one instantly interchangeable
unit.

The RA-1231 was a dual-gauge 35/16mm recorder, and was also the first
"Davis Loop" (AKA, "Davis tight loop") recorder.

The RA-1231 is easily the "exemplar" of all optical recorders. This
sixty-year-old machine is the basis of the Westrex/Nuoptix (now
Nuoptix/Photophone) stereo variable-area (S V-A) recorder, which, now,
records perhaps 99.44 percent of all optical tracks, produced
everywhere.

VD was abandoned primarily because of lab issues.

VA is now the de-facto standard not because of any presumed superiority
of VA over VD, but because 16mm is no longer an issue, in most cases,
and 35mm is now almost all stereo [ * ] , with the RA-1231's S V-A
valve being the only single-unit valve/optical system which is
implicitly time-aligned, and is eminently adaptable to stereo, two- or
four-channel.

[ * ] The RA-1231's dual-bilateral mono mode is simply a degenerate
case of its S V-A mode, but this fact was never fully appreciated by
industy researchers, although its capabilities were fully disclosed in
Frayne & Wolfe (1949), and elsewhere.


I strongly prefer VD over VA.

[peterh5322]

On 2007-06-20 09:51:41 -0700, Radium said:

I strongly prefer VD over VA.

And, I strongly prefer silver cars over any other color, especially red.

But, my preference reflects my prejudice, just as your immeasurable,
uninformed statement reflects your prejudice.

But, at least my prejudice has a measurable basis: silver cars get
significantly less ... very significantly less ... speeding tickets
than red cars.

[Radium[_4_]]

On Jun 20, 10:25 am, peterh5322
wrote:
On 2007-06-20 09:51:41 -0700, Radium said:

I strongly prefer VD over VA.

And, I strongly prefer silver cars over any other color, especially red.

But, my preference reflects my prejudice, just as your immeasurable,
uninformed statement reflects your prejudice.

But, at least my prejudice has a measurable basis:

The audio-artifacts specfic to an analog, VD, negative, B&W, optical
soundtrack are a mouth-watering, delicious, paradisiacal crackling
[due to black spots on the film] similar the baking of garlic bread in
a clay oven full of hot bituminous coals.

The fart of a magnetic, digital, VA, positive, and/or color soundtrack
is a hellish stink of stinky, thick, foamy, tickly, itchy, hissy,
terrifying, disgusting, and annoying human kakaa-gas of a human who
eats stale fat-free cheddar cheese, sticky fig newtons, cornstarch,
canned over-ripe mangoes, rotten lentils, and decaying cauliflower.

[[email protected]]

On Jun 20, 3:12 pm, Radium wrote:
On Jun 20, 10:25 am, peterh5322
wrote:

On 2007-06-20 09:51:41 -0700, Radium said:

I strongly prefer VD over VA.

And, I strongly prefer silver cars over any other color, especially red.

But, my preference reflects my prejudice, just as your immeasurable,
uninformed statement reflects your prejudice.

The audio-artifacts specfic to an analog, VD, negative, B&W, optical
soundtrack are a mouth-watering, delicious, paradisiacal crackling
[due to black spots on the film] similar the baking of garlic bread in
a clay oven full of hot bituminous coals.

The fart of a magnetic, digital, VA, positive, and/or color soundtrack
is a hellish stink of stinky, thick, foamy, tickly, itchy, hissy,
terrifying, disgusting, and annoying human kakaa-gas of a human who
eats stale fat-free cheddar cheese, sticky fig newtons, cornstarch,
canned over-ripe mangoes, rotten lentils, and decaying cauliflower.

You see what you get for feeding the village idiot?

[Early Film]

wrote:

You see what you get for feeding the village idiot?

Ugh! You're correct.

I assumed that Radium had a need to know.

Too bad he has never heard an original 1930s VD track negative printed
liquid gate, 'cause the hiss just goes bye-bye and the highs really pick up.

For the record:
I thought "galvo" or to use the more modern term, "light valve", but in
a senior moment, I wrote "head."

PeterH,
For some reason your posts did not propagate to my server. Your header
on google does not show commas between the groups. I haven't the
foggiest idea if this is the problem or not.

Earl.

[peterh5322]

On 2007-06-20 16:43:45 -0700, Early Film said:

For some reason your posts did not propagate to my server. Your header
on google does not show commas between the groups. I haven't the
foggiest idea if this is the problem or not.

Just as you use "Comedy", as an anti-spam measure for ".com", I use
"COMMINCH" (commander in chief) for the same purpose.

I have send the relevant post under separate cover.

[Radium[_4_]]

On Jun 20, 9:14 am, peterh5322
wrote:
On 2007-06-20 03:33:41 -0700, Early Film said:

Different recording heads may produce different artifacts, but in many
cases the same head can record both VA and VD.

In one case the head is the same, the Maurer.

Now, the Western Electric RA-1231 used the same valve for VA as for VD,
but the valve's integral optical system was different, as one might
expect.

Also, the valve unit was different for 16mm as for 35mm, but the
principle was the same: same valve, 35/16mm; different optical systems:
35mm VA, 35mm VD, 16mm VA, 16mm VD; in one instantly interchangeable
unit.

The RA-1231 was a dual-gauge 35/16mm recorder, and was also the first
"Davis Loop" (AKA, "Davis tight loop") recorder.

The RA-1231 is easily the "exemplar" of all optical recorders. This
sixty-year-old machine is the basis of the Westrex/Nuoptix (now
Nuoptix/Photophone) stereo variable-area (S V-A) recorder, which, now,
records perhaps 99.44 percent of all optical tracks, produced
everywhere.

VD was abandoned primarily because of lab issues.

VA is now the de-facto standard not because of any presumed superiority
of VA over VD, but because 16mm is no longer an issue, in most cases,
and 35mm is now almost all stereo [ * ] , with the RA-1231's S V-A
valve being the only single-unit valve/optical system which is
implicitly time-aligned, and is eminently adaptable to stereo, two- or
four-channel.

[ * ] The RA-1231's dual-bilateral mono mode is simply a degenerate
case of its S V-A mode, but this fact was never fully appreciated by
industy researchers, although its capabilities were fully disclosed in
Frayne & Wolfe (1949), and elsewhere.

No. I hate stereo. I want mono.

The audio-artifacts specfic to an analog, VD, negative, monoaural,
B&W, optical soundtrack are a mouth-watering, delicious, paradisiacal
crackling [due to black spots on the film prior to the recording] are
similar to the baking of garlic bread in a clay oven full of hot
bituminous coals.

[Karl Uppiano]

wrote in message
oups.com...
On Jun 20, 3:12 pm, Radium wrote:
On Jun 20, 10:25 am, peterh5322
wrote:

On 2007-06-20 09:51:41 -0700, Radium said:

I strongly prefer VD over VA.

And, I strongly prefer silver cars over any other color, especially
red.

But, my preference reflects my prejudice, just as your immeasurable,
uninformed statement reflects your prejudice.

The audio-artifacts specfic to an analog, VD, negative, B&W, optical
soundtrack are a mouth-watering, delicious, paradisiacal crackling
[due to black spots on the film] similar the baking of garlic bread in
a clay oven full of hot bituminous coals.

The fart of a magnetic, digital, VA, positive, and/or color soundtrack
is a hellish stink of stinky, thick, foamy, tickly, itchy, hissy,
terrifying, disgusting, and annoying human kakaa-gas of a human who
eats stale fat-free cheddar cheese, sticky fig newtons, cornstarch,
canned over-ripe mangoes, rotten lentils, and decaying cauliflower.

You see what you get for feeding the village idiot?

Too bad, too. Because by feigning real interest in the subject he got some
truly interesting, historical and technical responses. I wonder if he read
and understood them. I doubt it, although I got something out of it, so I
guess it wasn't a total loss (for me anyway).

[peterh5322]

On 2007-06-20 20:43:11 -0700, "Karl Uppiano" said:

Too bad, too.

Yup, as all the really "inside" stuff was discussed off-List, and
likely won't be posted here again in the next decade or two.


Because by feigning real interest in the subject he got some truly
interesting, historical and technical responses.


Well, if someone really wants to know, the best attitude is ask a
specfic question about who did what (or to whom), and await a response.

Expressing a prejudice which is not founded in reality is bound to
result in any relevant information being discussed off-List, if at all.


I wonder if he read and understood them.

Who cares.

[Steve Kraus]

Please note that almost all projection sound heads today are not
optimized for B&W VD tracks.

Are you talking about very currently (specifically reverse scan & red LED)
or just soundheads in general in recent times? If the latter in what way
were they lacking?

[peterh5322]

On 2007-06-21 20:31:12 -0700, Steve Kraus
said:

Please note that almost all projection sound heads today are not
optimized for B&W VD tracks.

Are you talking about very currently (specifically reverse scan & red
LED) or just soundheads in general in recent times? If the latter in
what way were they lacking?

I'm presuming reverse scan and red LED.

Kits are available for most good heads, even, I'm told, for the DP-70.

[Early Film]

I wrote:
Please note that almost all projection sound heads today are not
optimized for B&W VD tracks.

Steve Kraus asks:

Are you talking about very currently (specifically reverse scan & red LED)
or just soundheads in general in recent times? If the latter in what way
were they lacking?


Most new installations that were optimized for color non-applicated or
non-silver tracks, will distort slightly when a B&W VA track is played
and will distort rather badly when a B&W VD track is played. This is a
problem for theaters sometimes showing archive prints. Usually a
compromise can be reached where both can be played, but neither is at
optimum quality.

My experience has been with complains on the archive prints. I'd rather
some one who has more experience projecting non-applicated prints or
maintaining projectors comment on that part of the problem. We frankly
are not hearing about this problem as much now as we did a few years ago
and I assume that the Archive theaters have reached a compromise setting.

One other not very good solution has been to make the B&W VD tracks
slightly thiner (lighter), but this adds to the noise level. This was
done in testing, but I'm not aware of it being done in practice.

Earl

[Angelo Campanella]

Early Film wrote:
Radium asks:


Any artifacts caused by factors limited to the recording of the
negative?

Keep this stuff off of sci.acoustics

[Karl Uppiano]

"Early Film" wrote in message
...
Radium asks:

What audio artifacts are specific to the analog variable-density
optical audio tracks used in old B&W film - but don't occur in
magnetic audio tracks, in variable-area, in color tracks or digital
tracks?

Absolutely none.

The difference is in degrees.

VD tracks on B&W stock, are just more sensitive to printing defects,
especially intermodulation distortion due to exposure errors, but they did
provide the best sound quality for any all-analog sound system when done
correctly.

Please note that almost all projection sound heads today are not optimized
for B&W VD tracks.

The only process more critical of correct exposure than VD on B&W was VD
on color stock. (Exception: IB Technicolor, where the track was B&W)

Color VD was used in the early days before Labs started applicating
tracks. I've seen applicated VD color tracks in 16mm, but they were too
exacting to do on a regular basis.

How did they compensate for the non-linear characteristic of the emulsion in
VD tracks? It seems that VA would be more linear, since it is strictly a
geometric, not a photochemical transfer function. Am I missing something?

[Early Film]

Karl Uppiano wrote:

How did they compensate for the non-linear characteristic of the emulsion in
VD tracks?

By putting the exposure in the straight line portion of the H&D curve on
both the print and on the original negative, while keeping the print
thin enough to still play properly. The difficulty of getting this
correct was the reason for the demise of VD tracks. Most modern labs
simply don't want to waste time learning how to do this with sound,
although they do it with picture all the time.

It seems that VA would be more linear, since it is strictly a
geometric, not a photochemical transfer function. Am I missing something?

Yes, you are missing something.

In VA, you have image flare in the stock and that changes the shape of
the sound waveform. In VA, this happens in both width and in length.
In VD, it only happens only in length, so there is less likelihood of
that problem causing distortion, plus in VD you are recording a lower
contrast signal, so there is less flare to begin with.

In VA, since you have much more flare in the print stock than in the
negative stock, one has to greatly overexpose the negative to
intentionally get flare to cancel out the flare in the print.

Karl, I would have dropped the cross-posting, but I don't know which
group you are reading.

Earl in Rec.Arts.Movies.Tech

[Morgan Montague]

I, for one, find this an awesome thread here in RAMT. It is this sort of
minutea (meant in a good way) that keeps me coming back day after day. It's
the details that somehow always get f'd up in recording the history of
technology where you wind up with some of the most incredibly moronic press
releases, books, magazine articles and documentaries.

Thanks for all the serious questions and intelligent answers to this
discussion.

Morgan

"Early Film" wrote in message
...
Karl Uppiano wrote:

How did they compensate for the non-linear characteristic of the emulsion
in VD tracks?

By putting the exposure in the straight line portion of the H&D curve on
both the print and on the original negative, while keeping the print thin
enough to still play properly. The difficulty of getting this correct was
the reason for the demise of VD tracks. Most modern labs simply don't
want to waste time learning how to do this with sound, although they do it
with picture all the time.

It seems that VA would be more linear, since it is strictly a geometric,
not a photochemical transfer function. Am I missing something?

Yes, you are missing something.

In VA, you have image flare in the stock and that changes the shape of the
sound waveform. In VA, this happens in both width and in length. In VD,
it only happens only in length, so there is less likelihood of that
problem causing distortion, plus in VD you are recording a lower contrast
signal, so there is less flare to begin with.

In VA, since you have much more flare in the print stock than in the
negative stock, one has to greatly overexpose the negative to
intentionally get flare to cancel out the flare in the print.

Karl, I would have dropped the cross-posting, but I don't know which group
you are reading.

Earl in Rec.Arts.Movies.Tech