We’re always reformatting, and Physical Properties of … of Vinegar Syndrome •sour smell •Shrinkage •buckling of the emulsion •the appearance of crystals that obscure the

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Besser-Physical Properties of Film/Video, 9/6/05 1

Physical Properties ofFilm & Video

Howard Besser, DirectorMoving Image Archiving & Preservation Program

NYU’s Tisch School of the Artshttp://www.tisch.nyu.edu/preservation


We’re always reformatting, anddealing with wide variety of

formats• Nitrate• Super8• Cinemascope• 3-D• Cartridge• …


Technical Composition &Deterioration-

• Film• Video and Audio Tapes


Film LayersImage Permanance Institute


Film LayersScreenSound Film Preservation Handbook

• Topcoat• Emulsion (content)

• Subbing Layer (adhere)

• Base (cellulose triacetate,cellulose diacetate, cellulosenitrate, or polyester)

• Backing Layer


Surface Physical Damage

• Perforation• Scratches

• Water dropletdamage toemulsion

• ScreenSound Film PreservationHandbook

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Mold DamageScreenSound Film Preservation Handbook

• Usually in gelatin partof emulsion layer

• Interesting patterns


ShrinkageScreenSound Film Preservation Handbook


Vinegar Syndrome DeteriorationImage Permanance Institute


Signs of Vinegar Syndrome

• sour smell• Shrinkage• buckling of the emulsion• the appearance of crystals that obscure the image


Film--Acetate Decomposition cupping--Home Film Preservation Guide--filmforever.org


Film--Acetate Decompositionemulsion cracks--Home Film Preservation Guide--filmforever.org

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IPI A-D Strips


Acid Detection Strips at NYULibrary (Internship)


NYU University Archives Internship Project

Acid Detection results/autocatalyticpoint readings

0%0100%99Annette Weiner

87%3913%645Miscellaneous Films0%0100%1010Alice V. Keliher

0%0100%3737Abby Weed Grey0%0100%22External Affairs

71%1029%414Dept. of Athletics

1%199%100101Classics Dept. Tapes

0%0100%7575Brademas Papers23%2577%82107Audio Visual

19%7581%325400University Archives (in total)

% of 1.5– 3.0

1.5 – 3.0% of 0 – 1.00 – 1.0Total # ofitems

University ArchivesCollections


IPI Storage Guide


IPI Media StorageReference Guide


IPI Preservation Indextemperature/humidity, Years until noticeable deterioration

4713255010020080591630601252507061120408017535060714255010025050050

10183570150150

30070040122545902004009003016306012525060012502035º29º24º18º13º7º2º

Temperature Cº %

RH

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Improving storage inside the CanJean-Louis Bigourdan, AMIA 1998

• zeolites, silica gel, and low relative humiditypreconditioning help mostly by reducing moisturecontent

• acid adsorbents retard further decay• acid adsorbents do not reduce the acid content of

degraded film• the use of cardboard disks is not recommended


Improving storage outside the CanJean-Louis Bigourdan, AMIA 1998

• lowering temperature and/or relative humidity canhelp reduce the rate of acidification in degradingfilm

• trying to remove acid within the can does notoutweigh the benefits of low temperature andhumidity

• the greatest improvements in chemical stabilitycan be achieved with cold temperatures


Cineric Film Restoration (Internship)


Structure of TapeVan Bogart http://www.clir.org/pubs/reports/pub54

• Binder--Functions as a carrier for the recording material & Bonds it to the substrate

• Substrate--Base material on which the recording material is coated (eg. an aluminumplatter or a thin ribbon of polyester film)


Tape Substrate• Early tape used cellulose acetate

– Moisture/hydrolysis– Vinegar syndrome

• More recent tapes are polyester terephthalate(PET) or polyethylene napthalate (PEN)– Chemically stable– Resist hydrolysis and oxidation


Magnetic Particles• Store recorded information• Change in magnetic properties can

result in lossMagnetic remanence - ability to retain a

magnetic fieldCoercivity - ability to resist

demagnetizationMagnetic deterioration of the metal

particulate and chromium dioxidematerials

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Binder Layer

• Holds the magnetic particles to the base• Where the problems are likely to occur

binder-base adhesion oxide shedding dropoff hydrolysis

• sticky shed• magnetic head clog

• Tape baking as one solutionBesser-Physical Properties of Film/Video, 9/6/05 26

Video Cleaning Machine


Longitudinal RecordingVan Bogart http://www.clir.org/pubs/reports/pub54


Helical Scan RecordingVan Bogart http://www.clir.org/pubs/reports/pub54


Tape Pack ProblemsVan Bogart http://www.clir.org/pubs/reports/pub54


Tape Pack Problems

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Packing problems can lead toplayback problems

• Tracks for helical scan can be skewed


Storing Tapes

• Tapes should be stored fully wound in onedirection or the other

• Store tapes upright (like a book)• Do not store near potential magnetic fields• Storage cases should be opaque and kept

away from source of light and humidity• Do not store tapes in plastic bags• Exercise the tape every few years


Temperature & Humidity forTape Storage

• Variance of less than 2ºC and 5% RH per 24hours

• Ideally 8ºC and 25% RH• Other options

– 20°C (68°F) and 20-30% RH– 15°C (59°F) and 20-40% RH– 10°C (50°F) and 20-50% RH

• Never store below 8ºC

amianet.org 2003, & ISO 18923


VidiPax Video Preservation (Internship)


What can you do now?For both Film & Video

• Label elements as well as you can• Try to keep things at a low humidity and

temperature• Limit the number of formats as much as

possible• Save important production elements


Be concerned about ©• For preservation you may need to re-format, but with

recent changes in copyright laws, you may not have theright to re-format

• Intellectual property rights are very difficult, particularlyconsidering that most films and videos have extensiveunderlying rights that you could never get prior permissionfor (stock footage, historical footage, music composition,music performance, …) [“Eyes on the Prize”]

• And even if you have the right to re-format forpreservation, you might not have the right to show whatyou have preserved

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Physical Properties ofFilm & Video

Howard BesserNYU Moving Image Archiving & Preservation Program

http://www.tisch.nyu.edu/preservation

• http://www.amianet.org/• http://sunsite.berkeley.edu/Longevity/• http://www.imagepermanenceinstitute.org/• http://www.screensound.gov.au/screensound/screenso.nsf/

Documents

We’re always reformatting, and Physical Properties of … of Vinegar Syndrome •sour smell •Shrinkage •buckling of the emulsion •the appearance of crystals that obscure the