If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Variable Density Greyscale Film for audio
Hi:
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 |
#2
|
|||
|
|||
Variable Density Greyscale Film for audio
On 2006-09-20 20:27:41 -0700, "Radium" 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. 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. |
#3
|
|||
|
|||
Variable Density Greyscale Film for audio
peterh5322 wrote:
On 2006-09-20 20:27:41 -0700, "Radium" 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." |
#4
|
|||
|
|||
Variable Density Greyscale Film for audio
|
#5
|
|||
|
|||
Variable Density Greyscale Film for audio
peterh5322 wrote: On 2006-09-20 20:27:41 -0700, "Radium" 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. 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. |
#6
|
|||
|
|||
Variable Density Greyscale Film for audio
mono and VD.
That bears repeating. |
#7
|
|||
|
|||
Variable Density Greyscale Film for audio
mono and VD. That bears repeating. Yep. Those 2 are "fidelity" problems. |
#8
|
|||
|
|||
Variable Density Greyscale Film for audio
In article mNoRg.806$KK.532@trnddc08,
"Morgan Montague" wrote: mono and VD. That bears repeating. Yep. Those 2 are "fidelity" problems. Boo. Go to your room. P.S. -- verrry good..... |
#9
|
|||
|
|||
Variable Density Greyscale Film for audio
peterh5322 wrote:
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. |
#10
|
|||
|
|||
Variable Density Greyscale Film for audio
peterh5322 wrote:
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? --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Variable Density Greyscale Film for audio | Radium | In The Darkroom | 3 | September 26th 06 12:03 AM |
Pyro & selenium toning of negatives | Lew | In The Darkroom | 12 | September 21st 06 10:49 PM |
Focal plane vs. leaf shutters in MF SLRs | KM | Medium Format Photography Equipment | 724 | December 7th 04 10:58 AM |
Is it Copal or copal? Then what is it? | Nick Zentena | Large Format Photography Equipment | 14 | July 27th 04 03:31 AM |