IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner 1 Dietrich Schüller Recent Trends of Carrier Preservation IASA-TC 05 Handling and Storage of Audio and Video Carriers Co-Editor Albrecht Häfner A Preview Prepared for the Quinto Seminario Mexico City, November 2011

IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner 2 Publication follows concepts prepared for the IASA ICA-Seminar, Vienna 2004 TAPE tutorials Prepublication available at Architecture of the Publication 1 Introduction 2 Type of carriers 3 Environmental factors, handling 4 Storage facilities 5 Disaster preparedness: fire and water 6 Conclusion

IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner 3 1) Introduction Not a handbook of detailed knowledge in the field Structurally follows TC 04 Concentration on main carriers and main problems Points to special publications

IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner 4 2) Carriers Recording principles, composition and life expectancy, deterioration by replay, sizes and formats Mechanical Magnetic including HDD Optical Solid state carriers

IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner 5 3) Environmental factors, handling… Water / humidity Temperature Mechanical deformation Dust, foreign matter, (air) pollution Magnetic stray fields Light, ultraviolet radiation, x-rays Pest …across the carriers

IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner 6 4) Storage facilities Storage areas and their location Construction, materials, insulation Air conditioning Air quality and filtering Shelving Transport

IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner 7 5) Disaster preparedness General Fire Water

IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner 8 What is new compared to the last publications (Van Bogart, AES and ISO Standards, TAPE ? Absolute importance of relative humidity (RH) Relative importance of temperature Consequently, RH will be quoted first, temperature thereafter: e.g.: 35% RH, 20° C However: New insight in cellulose acetate deterioration suggests different RH values for AC tapes and lacquer discs: 50% RH as opposed to 40% and lower for other carriers

IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner 9 Stability of magnetic tape: Chemical composition important, but only smaller part Production process more important: success dependant from a number of variables Chemical analysis does not lead to conclusive results Batch related differences, explain often totally different behavior of tapes of same type of tapes

IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner 10 “Sticky Shed Syndrome”: Beyond hydrolysis of pigment binder probably several other reasons – most curable by elevated temperatures (“baking”) Empirical observation: SSS appears soon after production of tape, no reliable reports of appearance after 5-10 (?) years – not a general aging process (?) Consequently: research into life expectancy may not be of much use, specifically in view of unavailability of replay machines, their spare parts, and professional service

IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner 11 Consequently: Start digitisation as soon as possible Keep original carriers before digitisation under reasonable environmental conditions: dry cool clean Look on old standards…

IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner 12 Dry and cool: Theoretical ideal: keep temperature and humidity stable and low - Avoid (cyclic) changes of temperature and RH And: Temperature and humidity are interrelated: control both parameter simultaneously never cool storage area without dehumidification (humidity may raise excessively!) consequently...

IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner 13...split storage conditions: Audio and Video: Preservation storage: 25-30% RH  5%,  10°C  1° Access storage: 40% RH  5%,  20°C  3° Acclimatise when moving carriers from preservation to access store and relax tape based carriers Remember: New research suggest to keep cellulose acetate tapes and lacquer discs around 45-50% RH

IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner 14 Nota bene: any levels between 20 – 65% RH and °C (for photographic materials lower) are without immediate risk to AV carriers but: choice of storage conditions determines speed of degradation keeping to tight standards does not prevent degradation choose parameters which you can afford 24 h/day all year round And remember: RH is more important than temperature!

IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner 15 IASA-TC 05 images: a) Interlacing with text in the e-version b) Same in print version, if affordable - or DVD added?

IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner 16 Recording technology: DVD family read-out surface DS/SL DVD-ROM, DVD-RW printable surface read-out surface SS/DL DVD-ROM read-out surface DS/DL DVD-ROM SS=Single-Sided, DS=Double-Sided. SL=Single Layer, DL=Dual Layer clear polycarbonate substrate semi-reflective metal layer fully reflective metal layer adhesive protective layer laser beam SS/SL printable surface read-out surface DVD-ROM, DVD-R 1.2 mm

IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner 17 label (optional) label surface (top surface) 1.2 mm transparent polycarbonate substrate information layer transparent polycarbonate substrate NA = Numerical Aperture = 0,85 objective lens read-out surface (bottom) Scanning laser beam wavelength = 405 nm (blue-violet) focussing spot ca. 0,58  m Ø 0,1 mm cover layer (polycarbonate) Recording technology: Blu-ray

IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner µm CD 0.54 µm DVD 0.24µm BD Laser foci

IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner 19 track pitch 1.6 µm track width approx. 0.5 µm focussing spot approx. Ø 0.70 µm pit (or land) length min µm – max µm track pitch 0.74 µm track pitch 0.32 µm focussing spot 0.54 µm focussing spot 0.24 µm track width approx µm track width approx. 0.1 µm DVD BD

IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner 20 CD: Pits und Lands CD-ROM – replicated CD-R – burned Photo: Jean-Marc Fontaine

IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner 21 Pre-publication in TAPE Dietrich Schüller: Audio and video carriers. Recording principles, storage and handling, maintenance of equipment, format and equipment obsolescence. online.net/docs/audio_and_video_carriers.pdf

IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner 22 Announcement - Published August 2011: Dietrich Schüller: Audio and Video Materials in Tropical Countries. In: International Preservation News 54, def.pdf Third Version of an article originally published in IASA Journal 7/1996

IASA-TC 05 Handling and Storage of Audio and Video Carriers © 2011 Dietrich Schüller and Albrecht Häfner 23 Thank you !