This is topic Red (not cyan) soundtracks in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Peter Hall (Member # 695) on 07-01-2002, 12:45 PM:
Does anyone have experience with red soundtracks ? We've seen a few, mailny from Eastern Europe - looks like a standard SVA track but it's RED ! On playback (through a Kinoton FP20 with a standard tungsten exciter lamp and a normal stereo cell) sound is noisy and low level. Surely if the site had a red LED or laser reader, red light through a red track would make the track indefinable ? Assuming that the ideal wavelength of light source for playing a red track is half way between that of yellow and magenta (I guess around 490nm) this would give the worst possible reproduction ..Does anyone know if red tracks are in widespread use anywhere, and if so what results these territories get with LED or Laser readers ?
PS - shamless plug - if any cyan conversion kit can do this, our laser can ! Replaces the slit lens, can fit almost any projector, priced less than a good night out (in London, anyway !).
www.fproj.com/cyan
Cheers
Peter
Posted by Steve Guttag (Member # 268) on 07-01-2002, 12:51 PM:
If it is recent, I'd be more likely to suspect it was a High-Magenta track that didn't get it's application.Steve
------------------
"Old projectionists never die, they just changeover!"
Posted by John Pytlak (Member # 331) on 07-01-2002, 01:07 PM:
I'll second Steve's hypothesis that any recent "red" track is probably high magenta where the lab accidently did not redevelop the silver. Today, analog tracks are either the traditional cyan+magenta+silver, or the "high magenta" magenta+silver. There is no current practice of a magenta dye only track, much less a magenta+yellow (red) dye track.------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
e-mail: john.pytlak@kodak.com
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Posted by Ken McFall (Member # 845) on 07-01-2002, 01:24 PM:
Shameless plug right enough....
Posted by Bernard Tonks (Member # 809) on 07-01-2002, 01:32 PM:
As I mentioned in another thread sometime ago, the soundtrack had the same problem but was towards pink in colour. Needless to say that the sound reproduction was dreadful. Film was Message In A Bottle.
Posted by Leo Enticknap (Member # 534) on 07-01-2002, 03:08 PM:
Hi Peter:A misdeveloped hi-magenta track seems to me very likely if this is a recent film. If these are older prints, one other possibility springs to mind. There was recently a thread on the AMIA Internet list about discoloured optical tracks (both VA and VD) with the offending tracks being described as 'yellow', 'orange' and variants thereof. José Llufrío of the Cuban Film Institute offered the following explanation:
quote:
A sulphide track was used before efficient re-developers of Hidroquinone came into use. This was usual until well into the late 60's early 70's, as far as I remember from AGFA technical brochures I read around 1972.Sodium sulphide was mixed with a thickening agent, so it could be applied upon the sound track and not spread to the rest of the film. It acted very fast, providing a yellowish sound track, which would not change much in time (at least not within the time a print was supposed to last for release), and would be opaque enough for the photocell in the projector.
Given that Agfa, together with Orwo, virutally had the Eastern Bloc market in release print stock sewn up between them in those days, I guess this might be a possible explanation for the tracks you're coming across. But apparently this method of development is no longer in regular use, so if these are new(ish) prints, that wouldn't explain it.
Posted by Ray Derrick (Member # 1001) on 07-02-2002, 06:54 AM:
Peter, what you need is a cyan LED 
Or if it IS un-redeveloped magenta then a green LED 
------------------
Ray Derrick
President/Chief Engineer
Panalogic Corporation Sydney, Australia
Phone: 61 (0)2 9894 6655 Fax: 61 (0)2 9894 6935
Posted by Michael Brown (Member # 890) on 01-26-2003, 06:46 AM:
So if a Hi-Magenta track is printed correctly what colour does it appear to the eye?
Posted by Steve Kraus (Member # 476) on 01-26-2003, 10:31 AM:
Black just like the older cyan + magenta + silver tracks. The only easily visible difference is that there is sometimes a tiny sliver of a magenta line beyond the redeveloped area much as the other tracks sometimes showed a bit of purple there.
Posted by John Pytlak (Member # 331) on 01-27-2003, 11:04 AM:
The older exposure recommendation for analog soundtracks on color print film restricted exposure of the track to the sharp and fine-grained magenta and cyan dye layers. Without silver redevelopment, the track appeared dark blue. Redevelopment converted the silver halide back to silver, so the applicated area appeared dark gray, with a sliver of blue along the edges. These tracks had a slight difference in cross-modulation optimization density between white light and red LED readers:
http://www.kodak.com/US/en/motion/support/h44/
It was found that restricting the exposure to only the magenta layer ("high magenta") made the tracks more compatible with BOTH white light and red LED readers. Without silver redevelopment, the tracks are magenta colored. With silver redeveloped, the track appears dark magenta-gray, with magenta edges.
Cyan dye tracks REQUIRE a red LED reader, and will have only cyan dye and no silver, so they will look cyan in color:
http://www.kodak.com/US/en/motion/support/dyetrack.shtml
http://www.dyetracks.org