Caring for Audiovisual Material: Webinar 10/23/13 3 Videotape and Optical What Will be Covered Media Identification and Preservation Physical properties of media Preservation issues Webinar October 23, 2013 Formats and identification Linda Tadic Audiovisual Archive Network [email protected] 1 2 What Will Not be Covered Additional Resources Digitization (that’s the webinar on Bibliography of web-based readings October 30) Archival video preservation labs vendor list Cataloging and metadata (USA) List of current video formats 3 4 Videotape in Brief VIDEO If it has sprockets, it’s film – not video. 5 6 Heritage Preservation: Caring for Yesterday's Treasures--Today 1 Caring for Audiovisual Material: Webinar 10/23/13 3 Videotape in Brief Primary Concerns Like audiotape, videotape is magnetic Multitude of formats (identification can be media. difficult) Format obsolescence Video can come in reel or cassette form – Short Life Expectancy (LE) like audiotape. Environmental, organic, and human factors contributing to signal degradation It can carry both analog and digital signals – like audiotape. 7 8 How Videotape Started How Videotape Started Thank Bing Crosby. Original market/users: broadcasting First funded Like other time-based media, formats for development of audiotape. In 1950 the consumer market quickly followed. gave $50,000 to a start-up called Ampex NEVER intended as a preservation medium. to develop magnetic videotape. 9 10 Over … and unluckily for you, most are 60 formats have been introduced since 1956!!! 11 12 Heritage Preservation: Caring for Yesterday's Treasures--Today 2 Caring for Audiovisual Material: Webinar 10/23/13 3 Before Delving Into Formats Let’s understand the general preservation concerns based on videotape’s physical properties. …… obsolete 13 14 Videotape Properties Videotape Properties Van Bogart. Magnetic Tape Storage and Handling: A Guide for Libraries and Archives binder lubricant Backcoat: thin carbon-black ribbon (since Magnetic particle late 1960s). Magnetic coating: holds binder, magnetic Top coat particles, lubricant substrate Backcoat 15 16 Problem Areas Binder Of the 6 components making up videotape, Holds the magnetic particles. This is the four can contribute to signal degradation: weakest link. Binder Moisture in the air (high humidity) Lubricant contributes to hydrolysis (“sticky shed Metal Particles syndrome”). The binder starts breaking Substrate apart, and magnetic particles can be “shed” when tape is played. 17 18 Heritage Preservation: Caring for Yesterday's Treasures--Today 3 Caring for Audiovisual Material: Webinar 10/23/13 3 Binder Binder Shedding tapes can leave debris on video Moisture can also create mold on tapes. deck heads, damaging subsequent tapes. Losing magnetic particles from shedding causes drop-outs in the signal. Example: http://preservation.bavc.org/artifactatlas/ index.php/Video_Dropout Photo from Quad Tape Transfer: http://www.quadtapexfer.com/Moldex5.php 19 20 Treating Hydrolysis Treating Mold Once the binder starts breaking down, it The mold must be carefully removed from can’t be permanently stopped. the tapes and the tapes immediately transferred. Baking tapes at 122°F (50°C) for 3 days will Have a professional working with proper stabilize the binder long enough to equipment perform the cleaning. transfer the content. Transfer within 1-2 Breathing mold can endanger your health. weeks. ***SEEK EXPERT ADVICE*** 21 22 Lubricant Treating Lubricant Loss Lubricant helps the tape move through the Tapes can be re-lubricated, but should be decks. It will dry out over time; hot and done by a professional. dry environments will accelerate this natural process. Over-lubrication can cause signal loss. Dry tapes become brittle, and can get stuck in playback decks, damaging the tape. 23 24 Heritage Preservation: Caring for Yesterday's Treasures--Today 4 Caring for Audiovisual Material: Webinar 10/23/13 3 Magnetic Particles Magnetic Particles Magnetic particles store the information. Iron oxide. 2” Quad (earliest formats) They are held in the binder. Cobalt-doped iron oxide. Started with 1” Type C. Any magnetic particle loss is irretrievable. Chromium Oxide (CrO2). Small format cassettes and some VHS. Magnetic particle degradation evidence: diminished hue/color, reduced sound. cf. Wheeler, Videotape Preservation Handbook 25 26 Magnetic Particles and Oxidation Magnetic Particles Moisture + oxide = rust Barium ferrite (BaFe). Used in VHS tapes in mid-1990s and Betacam. BaFe has longer LE than MP, but not as efficient for recording. “Oxide”-based magnetic particles can degrade in high humidity environments. Metal particulate (MP). Used from BetaSP to the present. Particles are coated for protection against moisture in the air, but not effective when water-damaged. 27 28 Magnetic Particles Avoiding Particle Loss Metal evaporated (ME). ME tapes do not have a When it’s gone, it’s gone. binder. Magnetic particles are laid down directly to the tape substrate. Found in small-format Keep tapes cool and dry to slow down loss. cassettes (Hi8, Digital8, DVCAM, MiniDV). Transfer content from ME tapes as soon as Thinner magnetic coating, so tapes more fragile. possible. ’ Repeated plays and leaving tapes in “pause” can Don t leave tapes in pause. damage the tape, resulting in particle loss. Don’t play ME tapes more than 5 times before transferring. Archivists follow “5 play rule,” then must Transfer content from tapes with evidence of transfer. metal particle loss. 29 30 Heritage Preservation: Caring for Yesterday's Treasures--Today 5 Caring for Audiovisual Material: Webinar 10/23/13 3 Substrate (basefilm or carrier) Control Track Not a physical property, but impacts the Made of polyester of varying thickness. Supports readability of an analog signal. the magnetic coating. Pulse to drive the tape through the VTR Chemically stable, but can stretch. Stretching can according to the speed recorded on the be caused by: poor tape pack and high control track. Recorded at the edge of the humidity/temperature. tape. (Similar to film’s “sprockets”) If damaged, there can be drop-outs, If stretches, control track can be damaged and freezes, and “glitches” as the tape and tape won’t run through the deck. VTR lose sync. 31 32 Avoid Substrate Deformation Videotape Conservation Store tapes in a cool Videotape Life Expectancy (LE): between 5 to 50 and dry environment years, depending on format, tape stock, and storage environment. Make sure the tape has an even BAD! “pack” (no popped “LE” does not mean total signal loss, but the point strands) where the signal is obviously deteriorating and the content should be transferred. What can be done to extend LE? 33 34 Micro Steps Micro Steps DVCAM Set tape cassette to Store standing up (like books). If stored SAVE (e.g., not flat, gravity will loosen tightness of tape RECORD). For pack. U-matics, this means removing the red Tapes should have an even, flat wind with button in the back. no popped strands. U-matic 35 36 Heritage Preservation: Caring for Yesterday's Treasures--Today 6 Caring for Audiovisual Material: Webinar 10/23/13 3 Micro Steps Micro Steps Re-house tapes to inert plastic containers. Prioritize re-housing tapes in cardboard containers; cardboard/paper accelerates BAD! hydrolysis and mold. Remove any paper inserts from inside Wind to head or end; never leave the tape cases to diminish hydrolysis. exposed. 37 38 Macro Environment (Storage) ANSI IT9.23-1996 Do not store tapes in non-archival or stock USE TEMP RH boxes. short-term storage (content used 68° F 20-30% daily) Use metal shelves – definitely not wood. medium-term storage (content 59° F 20-40% used up to 10 years before Cool and dry environments will slow down moved or discarded) deterioration. long-term storage 50° F 20-50% Magnetic media need not be stored in as cold an environment as film. 39 40 Storage General Tips Storage General Tips Videotape should never be stored A higher temperature must be balanced by above 65% RH. At that rate, fungal lower humidity. growth will occur. Fluctuations of +/- 5% RH or 7°F within a Videotape should not be stored below 24-hour period can cause more damage 45°F. Storage below this can result in than consistently high temperature or binder break-down. humidity. 41 42 Heritage Preservation: Caring for Yesterday's Treasures--Today 7 Caring for Audiovisual Material: Webinar 10/23/13 3 Prioritization How Would You Prioritize? 2” videoreel ¾” U-matic MiniDV on ME stock The oldest tapes should not necessarily be preserved first. Recorded 1969 (44 y/o) Recorded 1975 (38y/o) Recorded 1998 (15 y/o) Stored at 65 °F / 35% RH since Stored at 55° F / 50% RH Stored at 78° F / 45% RH 1969 past 10 years; at 80° for past 5 years; Besides age, also consider: F / 60% RH previous unknown before 28 years Condition Used a few times in first 5 years, Heavily used first 15 Heavily used first year; then put in deep storage years occasional use since Inherent format stability Storage environment over a tape’s life Obsolete format, but a few vendors Obsolete format, but old Active format, equipment available equipment and some available Active use vendors available 43 44 Format Obsolescence What does “obsolete” mean? Questions on conservation actions? Stock is no longer manufactured Playback equipment is no longer manufactured and old decks are in limited supply 45 46 Endangered Wake-up Call A format can be “endangered” rather than obsolete if there is an adequate supply of Review the handout “Video stock and decks operating playback decks. manufactured as of October 2013” 47 48 Heritage Preservation: Caring for Yesterday's Treasures--Today 8 Caring for Audiovisual Material: Webinar 10/23/13 3 Digitization as Preservation Before Transferring You MUST digitize videotapes for Know the format preservation. Identify the tape’s maximum running time to help estimate transfer costs and digital Do NOT transfer video to video – the storage.