Variable Density Greyscale Film for audio
Radium
I like using variable-density analog B&W negative film optical tracks
for audio. The audio characteristics of the film make my mouth-water.
Yes, for some wierd reason, the film's audio makes me hungry.
Audio signal, in the form of light changing its intensity in a
analogous manner to the sound, is shined onto a negative film. The film
is developed and playback is accomplished by shining light of a
constant intensity onto the developed film. As the light goes through
the film, the patterns on the film will change the intensity of the
light that is received by a photoelectric cell. The change in light
intensity results in a changing electric current which is sent into an
amplifier and then to a loudspeaker.
http://www.mtsu.edu/~smpte/twenties.html
"The Tri Ergon Process uses a technology known as variable density,
which differed from a later process known as variable area. The Tri
Ergon process had a pattented flywheel mechanism on a sprocket which
prevented variations in film speed. This flywheel helped prevent
distortion of the audio. Tri Ergon relied on the use of a
photo-electric cell to transduce mechanicalsound vibrations into
electrical waveforms and then convert the electrical waveforms into
light waves. These light waves could then be optically recorded onto
the edge of the film through a photographic process. Another
photo-electric cell could then be used to tranduce the waveform on the
film into an electrical waveform during projection. This waveform
could then be amplified and played to the audience in the Theater. The
Fox Film Corporation acquired the rights to the Tri Ergon technology in
1927. "
The ERPI system, Fox-Case's Movietone, and De Forest's Phonofilm use
variable-density recording film audio
Regards,
Radium
peterh5322
> The ERPI system, Fox-Case's Movietone, and De Forest's Phonofilm use
> variable-density recording film audio
But, no one makes variable density sound recoding film, nor do the labs
know how to process VD properly.
And, I'd bet nearly every WECo RA-1231 ever made has been converted
from its original VD mode to VA mode, and to Stereo Variable-Area, at
that.
RA-1231s are still in new production, and are pretty much as WECo
designed them in 1947, and with the valve as WECo designed in 1937, but
changed for SV-A.
Scott Dorsey
>On 2006-09-20 20:27:41 -0700, "Radium" <gluc...@excite.com> said:
>
>> The ERPI system, Fox-Case's Movietone, and De Forest's Phonofilm use
>> variable-density recording film audio
>
>But, no one makes variable density sound recoding film, nor do the labs
>know how to process VD properly.
7302 will work acceptably well. I have run it through an Auricon
sound recorder and just processed in neg chemistry for a gamma of around .6
and it didn't sound all that good, but it was okay.
>And, I'd bet nearly every WECo RA-1231 ever made has been converted
>from its original VD mode to VA mode, and to Stereo Variable-Area, at
>that.
I would not be surprised if there are some folks with the WECO and RCA
sound cameras that still had a VD mode to them. Quite honestly, if
you just stick a diffuser behind the slit, you get VD.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
peterh5322
> I would not be surprised if there are some folks with the WECO and RCA
> sound cameras that still had a VD mode to them. Quite honestly, if
> you just stick a diffuser behind the slit, you get VD.
The optical path is the same, but differs by one lens element.
Only Marurer had a path which was selectable by the user.
With the others, you interchaged the valve and its optical system.
Radium
peterh5322 wrote:
> On 2006-09-20 20:27:41 -0700, "Radium" <gluc...@excite.com> said:
>
> > The ERPI system, Fox-Case's Movietone, and De Forest's Phonofilm use
> > variable-density recording film audio
>
> But, no one makes variable density sound recoding film, nor do the labs
> know how to process VD properly.
>
> And, I'd bet nearly every WECo RA-1231 ever made has been converted
> from its original VD mode to VA mode, and to Stereo Variable-Area, at
> that.
>
I prefer mine to be mono and VD.
Steve Kraus
That bears repeating. ;)
Morgan Montague
>> mono and VD.
>
> That bears repeating. ;)
Yep. Those 2 are "fidelity" problems.
Josiah Gluck
"Morgan Montague" <cine...@verizon.net> wrote:
Boo.
Go to your room.
P.S. -- verrry good.....
EarlyFilm
> But, no one makes variable density sound recoding film,
Yup! But if you can get enough light, 2234 dupe negative stock will
work. If you can't get enough light to expose D/N stock then finegrain
stock will work better than print stock, but the contrast is higher than
ideal.
> nor do the labs know how to process VD properly.
A few still do, but it is a dying skill.
Earl.
Scott Dorsey
>
>> But, no one makes variable density sound recoding film,
>
>Yup! But if you can get enough light, 2234 dupe negative stock will
>work. If you can't get enough light to expose D/N stock then finegrain
>stock will work better than print stock, but the contrast is higher than
>ideal.
5378 can be made pretty wide tone if processed in a super-low contrast
developer. In Technidol, I can get the gamma down to 0.65 but the ASA
rating drops down to 40.
2234 is SLOW. Grain structure is good, and the gamma is very low but
easily controlled. What's the approximate ASA or photorecording sensitivity
on that stuff? It's got to be insane. Less than 5366 even.
>> nor do the labs know how to process VD properly.
>
>A few still do, but it is a dying skill.
Which ones, out of curiosity?
EarlyFilm
> 2234 is SLOW. Grain structure is good, and the gamma is very low but
> easily controlled. What's the approximate ASA or photorecording sensitivity
> on that stuff? It's got to be insane. Less than 5366 even.
At 60 gamma, 5234/2234 has an ASA of between 5 and 10 tungsten,
depending on the exact mixture and temperature of the chemistry.
J. Theakston
Scott Dorsey wrote:
> Which ones, out of curiosity?
Not sure who still does b/w VD, but Triage and John E. Allen are the
last that I can think of that do excellent density tracks on color
stock.
J. Theakston
Scott Dorsey
And I should expect to gain about half a stop if I run it through the
reversal machine, I hope.
EarlyFilm
>>Scott Dorsey asks:
>>>2234 is SLOW. Grain structure is good, and the gamma is very low but
>>>easily controlled. What's the approximate ASA or photorecording sensitivity
>>>on that stuff? It's got to be insane. Less than 5366 even.
>> Early film replied:
>>At 60 gamma, 5234/2234 has an ASA of between 5 and 10 tungsten,
>>depending on the exact mixture and temperature of the chemistry.
Scott states:
> And I should expect to gain about half a stop if I run it through the
> reversal machine, I hope.
Scott, If you plan on printing it, a reversal "negative" will sound like
crap. If you project the original, it might sound OK but all direct
recording that I've heard sounds greatly inferior to properly exposed
negative-to-positive track.
Where, may I ask, will you get it processed reversal since the EPA has
come down on the chemicals formerly used?
It has been 25 years since I reversed any 7234 and I don't remember the
speed shift, just that it was a pain in the arse to get consistent
results -- and that was for picture use. When you are making a burn
matt and a holdback matt at the same time, if you screw either one up,
you must do both over again to achieve perfect alignment. I only used
7234 D/N stock when the job forced me to use a panchromatic stock for
the matts. (The specialty stocks used for 35mm matts were not made in
16mm. For matts, I preferred to use either sound recording stock or
7366 finegrain stock, both of which are ortho.)
Earl.
Scott Dorsey
>
>Scott, If you plan on printing it, a reversal "negative" will sound like
>crap. If you project the original, it might sound OK but all direct
>recording that I've heard sounds greatly inferior to properly exposed
>negative-to-positive track.
That makes sense, although it allows me to save a step.
>Where, may I ask, will you get it processed reversal since the EPA has
>come down on the chemicals formerly used?
I get it done at A-1 in Manhattan. Kodak basically dropped the old reversal
chemistry and replaced the bleach with one that is less environmentally
nasty but more corrosive. They then replaced Tri-X and Plus-X reversal
last year with finer-grain versions that are tuned for use with the new
chemistry. The stuff looks good.
I have been running variable area tracks on 7378 through the reversal
chemistry and getting pretty decent results. Cross-modulation tests come
out with similar numbers as the negative, and of course you can make
prints from reversal originals without an intermediate.
>It has been 25 years since I reversed any 7234 and I don't remember the
>speed shift, just that it was a pain in the arse to get consistent
>results -- and that was for picture use. When you are making a burn
>matt and a holdback matt at the same time, if you screw either one up,
>you must do both over again to achieve perfect alignment. I only used
>7234 D/N stock when the job forced me to use a panchromatic stock for
>the matts. (The specialty stocks used for 35mm matts were not made in
>16mm. For matts, I preferred to use either sound recording stock or
>7366 finegrain stock, both of which are ortho.)
The modern 7378 sound recording stock is WAY higher contrast and finer grain
than the pre-EXR stock from a decade ago. It's made that sort of work
a good bit easier.
A short film that I shot mostly on 7366 which was processed in reversal
by A-1 can be seen this week at http://www.countgore.com/NewBlood.htm. Note
that the transfer was done by pointing a video camera at the flatbed
and you're listening to the optical track, so don't expect the best
possible quality....
EarlyFilm
> I have been running variable area tracks on 7378 through the reversal
> chemistry and getting pretty decent results.
VA tracks don't mush up as fast as VD in direct positive.
> A short film that I shot mostly on 7366 which was processed in reversal
> by A-1 can be seen this week at http://www.countgore.com/NewBlood.htm. Note
> that the transfer was done by pointing a video camera at the flatbed
> and you're listening to the optical track, so don't expect the best
> possible quality....
Scott,
You shot a flame on extremely slow ortho finegrain master positive stock
which you had reversal processed?????
I'm impressed, but how and why?
Flames are hard enough to shoot and make look good with the faster
stocks intended for camera.
Estar base 3366 might be OK for projection, but the acetate base 7366
stock tends to warp and/or cup under the heat of the projection lamp.
A few years ago, the base in 7302 and 7366 were slightly different in
chemistry and only the print stock resisted heat warp. I assume, but am
not sure, if this is still the case.
Earl.
Scott Dorsey
>Scott Dorsey wrote:
>> A short film that I shot mostly on 7366 which was processed in reversal
>> by A-1 can be seen this week at http://www.countgore.com/NewBlood.htm. Note
>> that the transfer was done by pointing a video camera at the flatbed
>> and you're listening to the optical track, so don't expect the best
>> possible quality....
>
>which you had reversal processed?????
>
>I'm impressed, but how and why?
Because I had a couple cans of it lying around that were going to be pitched
and I thought I'd put it in the camera and see what happens. I shot a test
, then I shot some more stuff, and next thing I knew I had most of a short
movie.
Some of the indoor stuff was done on 7207 Tri-X RP film, which was an RAR
film for rapid processing. Also sitting in the lab junk closet for years.
You can see it has occasional splotches on it from condensation due to the
cans not being very well-sealed.
>Flames are hard enough to shoot and make look good with the faster
>stocks intended for camera.
The color section with the flames was shot on 7239 that was about fifteen
years out of date. That section actually has a dye soundtrack (printed
from a 7378 master sound positive that was run through the reversal machine),
and the sound level is about 12 dB lower than the B&W sections that were
printed on standard B&W reversal print stock. I cranked it up in the transfer
which is why the noise level is so much higher.
>Estar base 3366 might be OK for projection, but the acetate base 7366
>stock tends to warp and/or cup under the heat of the projection lamp.
>
>A few years ago, the base in 7302 and 7366 were slightly different in
>chemistry and only the print stock resisted heat warp. I assume, but am
> not sure, if this is still the case.
It would be interesting to see. The standard B&W reversal print stock has
been discontinued as part of the new chemistry, and I have been playing
around trying the various other stocks for printing reversal originals in
the past six months. 7366 is okay but the gamma is a little high... but
to be honest I did not try particularly heavy runs through projectors to
see how rugged it would be. 7302 is way, way too high gamma. Even if I
preflash and pull back a stop, 7302 in the reversal machine gives me
a gamma greater than .70. It's a shame since we have a fridge full of
7302 around here that's getting older every day.
What is REALLY weird is that I recently got a TV print that had been made
on 7340. And... it actually had a decent D-max and some detail in the
shadows! It wasn't wonderful, but it was entirely acceptable and I am
really curious how they managed that.
nicep...@gmail.com
That's funny--I thought one got VD from toilet seats...I'll have to
tell my mom, she obviously had it wrong!
Radium
Forget the reversal or the positive. I prefer to use the original
negative film.
Radium
Not for me. I think mono and VD are better in quality. I don't like
stereo or VA. But then, "quality" is highly subjective. One's worst
enemy can be another's best friend.
Radium
Speaking of flames, I'd like the light in my equipment to be powered by
an anthracite-fueled fire.
Radium
And maybe -- or maybe not -- some fire fueled by bituminous coal.
J. Theakston
Radium wrote:
> Forget the reversal or the positive. I prefer to use the original
> negative film.
THIRD BASE!!!
J. Theakston
Radium
What do you mean?
el...@no.spam
Radium <gluc...@excite.com> wrote:
>> THIRD BASE!!!
>>
>> J. Theakston
>What do you mean?
No, What's on second.
Scott Dorsey
>J. Theakston wrote:
>> Radium wrote:
>> > Forget the reversal or the positive. I prefer to use the original
>> > negative film.
>>
>> THIRD BASE!!!
>
Russian spy on phone: Hello, Uncle Joe? Yeah... They got a base in Cuba, they got a
base in Japan... now they got a base in Turkey. Just wanted you to know. Thanks!
<hangs up>
Lou Costello: I heard you talking about bases, and I just wanted to ask what...
Russian spy: What's on second...