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Topic: Help - can anybody here record on 35mm mag (cs format)?

Stephen Furley
Film God

Posts: 3059
From: Coulsdon, Croydon, England
Registered: May 2002

posted 06-13-2004 04:34 AM

I have 35mm 4-track tone and pink loops, but the stripe is breaking up. Is there anybody here who could record new ones for me? I have a just about long enough length of striped blank stock that I could send, I know that this stuff is just about impossible to get hold of now.

Many thanks if anybody is able to help.

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Scott Norwood
Film God

Posts: 8146
From: Boston, MA. USA (1774.21 miles northeast of Dallas)
Registered: Jun 99

posted 06-13-2004 07:36 AM

I have single-track tone and pink-noise loops (and some unlabeled mag stuff as well). They are kind of old (I'm guessing '80s vintage), but I'll send them along if you want them.

Edit: oh, wait, mine are for dubbers, not CS format. Never mind.

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Gordon McLeod
Film God

Posts: 9532
From: Toronto Ontario Canada
Registered: Jun 99

posted 06-13-2004 09:44 AM

I have been trying for a long time to get a set of erase and recording heads for 4 track for either the westrex or magnatech dubbers I have to do just that
Then finding the CS perf magstripped stock is the next issue

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

posted 06-13-2004 11:26 AM

Gord,
You might try Scott Sound in Burbank. They probably have 4 track CS type heads in stock. MAny places will also make the heads for you on special order. You don't need the erase head anyway just bulk erase the stock, you'll hvae better S/N if you do. The mag stock is really the problem at hand... I wonder if John P. knows whan the last time was that Kodak even made CS perforated stock?

Mark @ CLACO

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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999

posted 06-13-2004 11:50 AM

You can actually cheat the striped 4-track with full coat...the perforations will muck with the surround calibration, as I recall. You also have a fringing effect (exaggerated bass).

Some of the easternblock Euro countries were still using striped 4-track film rather late in the game...found this out doing embassy work.

Steve

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Frank Angel
Film God

Posts: 5305
From: Brooklyn NY USA
Registered: Dec 1999

posted 06-13-2004 03:54 PM

Stephen,

I think I have some 4trk tone, but will have to check. I can't remember if it is sweep or just 1k ref or what, but I can let you have enough for a couple of loops. Let me check. email me in a few days and I will let you know what it is. I am almost sure it is not pink noise, which is what would really be nice.

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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999

posted 06-13-2004 04:25 PM

FANTASIA and YENTLE were the only two features where I laid my hands on actual Pink Noise on 4-track striped film. Now 1K tone was available from SMPTE, primarly for balancing projectors in a 2-projector system and channel balance...being pre-Dolby the level was less regulated. So everything was balanced but you were expected to use your projector gain controls to set auditorium levels.

Steve

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John Pytlak
Film God

Posts: 9987
From: Rochester, NY 14650-1922
Registered: Jan 2000

posted 06-14-2004 08:36 AM

In the May 2004 SMPTE Journal:

SMPTE Journal May 2004 (Membership Required)

quote:
50 Years Ago in the Journal

The May 1954 Journal reported in “Progress Committee Report” by Charles R. Daily: “...The four magnetic stripes used on CinemaScope tremendously expanded the use of striped magnetic sound films. Reeves Soundcraft produced a new striping machine for Twentieth Century-Fox Film which applies the four magnetic soundtracks to the color release prints at 150 ft/min. The machine uses the familiar method of flowing a suspension of magnetic oxide onto the film from a properly shaped and calibrated orifice. Reeves Soundcraft have made available pre-striped raw stock in a variety of combinations including 35mm and 16mm sound-recording negative, Panchromatic and certain reversal color films. The sound recording material is used by Columbia and others to record simultaneously an optical track and a magnetic track on the same film. The optical track is then used in editing and the final mix is made from the magnetic stripe, thus preserving the quality advantage of the magnetic system for the final mix.”

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David Graham Rose
Expert Film Handler

Posts: 187
From: Cambridge, UK
Registered: Sep 2002

posted 06-14-2004 02:02 PM

Greetings to you Stephen

Not entirely sure where one would go for his type of service in the UK, but one could try Bell Theatre Services. They seem to have a great deal of equipment available whenever I need any specialist loops recorded. They can be found at 9b Chester Road, Borehamwood, England, WD6 1LT. Tel 020 8238 6000.

I'm sure that if Graham there can't assist then he will inevitably know someone who does, or will tell you in detail about facilities that were able to offer this service in the past.

From a warm Summers Eve in Cambridge, I bid you Good Evening

David

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Michael Schaffer
"Where is the
Boardwalk Hotel?"

Posts: 4143
From: Boston, MA
Registered: Apr 2002

posted 06-14-2004 03:28 PM

Somebody told me that they can`t make magnetic striped film in california anymore for environmental reasons, but I don`t recall the details. Am I confusing this or is it true?

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John Pytlak
Film God

Posts: 9987
From: Rochester, NY 14650-1922
Registered: Jan 2000

posted 06-14-2004 04:05 PM

It's not that you can't, it's just that the cost of recovering the solvent vapors to meet current environmental standards is cost-prohibitive, and the small volumes of striping just didn't justify the capital investment required.

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Frank Angel
Film God

Posts: 5305
From: Brooklyn NY USA
Registered: Dec 1999

posted 06-14-2004 07:49 PM

Steve is right, the ref tones on mag test film were really to balance everything out, not to actually eq anything as is done with the Dolby 1/3rd eq Cats in the analog CP playback.

Which brings up another question: am I correct in saying that the 1/3rd octave eq on the analog CPs is only applied to the optical sync sound? So this would mean that the mag tracks that are passed through the CPs are not 3rd octave eq-ed? Wouldn't this put the mag tracks at a decided disadvantage? Couldn't an outboard 1/3rd octave eq be employed to do what the 1/3rd octave eq does for the optical tracks?

In our house the system is already 1/3rd octave eq-ed for the B-chain as the projection system is only a subsystem of the entire audio system. The CP 1/3rd octave eq is only used to compensate for the optical playback anomalies in the A-Chain (very little is really needed -- almost all the controls except at the extremes wind up being pretty much at 0). The projection output is tweaked to flat for input to the main system and it is in the main system where the room is voiced at 1/6th octave digitally.

One of my friends was interested in getting pink noise into his mag system as he was using mag preamps from old Skully 4 track, 1in studio tape decks. They have high and low end eq as well as head-gap compensation. Without either a tone sweep test film or some pink noise film, there was no way to adjust these variables. What he did was, he took a unit designed to allow a portable CD to play in a car radio through its cassette deck.

Basically what it is, is a transducer head that the audio signal energizes and which is pressed up against the playback head of the cassette deck and thus the audio signal is induced into the head same as if the tape were inducing it. My friend used a regular pink noise generator to input the signal to this induction unit and then pressed the induction head against the mag playback heads, each in turn, in the penthouse. I wasn't there to actually see the results, but he was ecstatic and claimed it was a great help in adjusting the head levels and setting the mag preamp eqs. Steve, maybe could rig something like that. It might be easier than hunting around for old test film that probably isn't much more reliable for retaining accurate reference levels of flux across the tracks than your old stuff is. Magnetism is an elusive property....sometimes it sticks, sometimes it doesn't.

In the early days of CinemaScope 4trk mag prints, there were tales of prints getting their mag levels attenuated merely by shipping them back and forth across the Rockies; supposedly the earth's magnetism over a number of passes could actually act as a giant degausser. I don't know if this could actually happen or it was just a lab's excuse for sending out a print that had below spec low levels, but I heard this from a number of old timers. Seems to me tapes are sent back and forth cross country all the time without such dire consequences. But I repeat the story here because it was told to me as a green kid, and now that I am on the verge of old-foggie-ism, I get to tell these tall tails to the younguns.

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Rick Hunter
Master Film Handler

Posts: 452
From: Melbourne, Australia
Registered: Feb 2003

posted 06-14-2004 08:05 PM

There is the tale from the 'old days' where the projectionist managed to partly erase a mag print by transporting it from the exchange to the theatre here in Melbourne by tram.
The magnetic fields from the traction motors did the dastardly deed.
A lesson well learnt.

Regards,
Rick

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Steve Kraus
Film God

Posts: 4094
From: Chicago, IL, USA
Registered: May 2000

posted 06-15-2004 12:29 AM

Likely an urban legend. How many transit systems use mag stripe fare cards? What about all those credit cards with mag stripes in people's wallets? I think the frame structure of the motor would mostly contain the high strength field just as it does on a transformer. Close contact perhaps...but sitting meters away with intervening structure which is likely ferrous? Doesn't seem likely although one never says never.

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Rick Hunter
Master Film Handler

Posts: 452
From: Melbourne, Australia
Registered: Feb 2003

posted 06-15-2004 04:07 AM

Alas, Steve, it is true.
I am talking of the early sixties where we only had money, not credit cards, and with the film cans sitting on the wooden floor of the tram the motor is was only a foot or so away.
I am not talking of complete erasure but major loss on what were the outer layers of film on the 'motor' side of the reels.
The print had to be sent back to the states for re-recording.

Rick

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