Introduction

Digital Betacam was introduced by Sony in 1993. Commonly known as "DigiBeta," the format was a replacement for the analog Betacam SP format. Digital Betacam was superior to DVCAM and DVCPRO but cheaper than D1. Small cassettes were used in cameras and large cassettes were used in video recording and editing decks. It was a popular digital videocassette format for broadcast television use and was considered a low-risk preservation master format until very recently.

Digital Betacam records component video with 10-bit YUV 4:2:2 compression. The tape includes four audio channels (48 kHz / 20 bit PCM-encoded digital audio) plus a fifth analog audio track for cuing. The tape also includes a linear timecode track.

Digital Betacam decks implemented an SDI coaxial digital connection, which allowed video production facilities to transmit digital signals on existing coaxial wiring without having to commit to rewiring other equipment.

Identification

Image source

Maxell BD-40 40-Minute Digital Betacam Video Cassette in Album Case (Small). B&H Foto & Electronics Corp. Accessed February 22, 2021.

Image source

Maxell BD-40 40-Minute Digital Betacam Video Cassette in Album Case (Small). B&H Foto & Electronics Corp. Accessed February 22, 2021.

Physical characteristics

Tape width	1/2 inch
Tape composition	Metal particulate
Cassette dimensions	small cassette: 6⅛" × 3¾" × 1" large cassette: 9⅓" × 5⅔" × 1"
Container dimensions	Most common containers are the manufacturer's hard plastic snap-closure cases. Small cassette cases: 6¾" x 4⅜" x 1¼" Large cassette cases are 10⅝" x 6⅜" x 1¼"
Identifying features	Cassettes are usually labelled "Digital Betacam" in the upper right corner
Common manufacturers/brands	Sony
Playback	Requires camera or deck manufactured for Digital Betacam format. Some Digital Betcam equipment is backwards-compatible with Betacam and Betacam SP.

Technical characteristics

Record time	Small cassettes: up to 40 minutes Large cassettes: up to 124 minutes
Bitrate	90 Mbit/s
Bit depth	10 bit
Colour sampling	4:2:2
Resolution	NTSC: 720x480 PAL: 720x576
Compression	2.34-to-1 DCT compression

Storage

Storage environment: temperature	Ideal: 40–54°F (4.5–12°C) Acceptable: 55–60°F (13–15.5°C)
Storage environment: humidity	30-50% RH
Container	Digital Betacam containers should pass the Photographic Activity Test (PAT) as specified ISO Standard 18916:2007 Plastic: Polyethylene, polypropylene, or polyester (a.k.a. Mylar D or Melinex 516). No PVC or acetate Paper/Paperboard: If paper containers are necessary, they should be constructed from lignin-free, neutral pH paper/paperboard Containers are acceptable if they: Are clean and free of mould Protect the media from dust and other contaminants Are not introducing contaminants through degradation Unacceptable containers must be replaced with clean, inert containers.
Orientation of tape in storage	Vertical on its end (like books)

Types of damage and deterioration

Binder deterioration

Image source

"1.1.3. Inspect for damage / Look for chemical deterioration / Binder degradation". In Audio Tape Digitisation Workflow. Accessed February 22, 2021.

Description

Commonly known as "sticky shed syndrome." Affected records will have a visible gummy or powdery residue on the surface of the tape. This can damage both the recorded material and playback equipment. Back-coated tapes are most affected by this type of deterioration.

Cause

Polyester urethane is prone to moisture absorption which can cause the molecular structure of the binder to break down. This process is accelerated by high temperature and high humidity.

Remedy

Environmental conditioning: Moving the tape to a controlled storage environment (40°C / 20 to 25% Relative Humidity) may reverse the affects of hydrolysis over time.

Baking: Holding the tape at an elevated temperature (45°C to 55°C) for a brief period of time (up to 36 hours) can temporarily remove moisture and allow normal playback for a period of one to two weeks. Tapes should not be rewound before baking.

Drop-out

Image source

"1.1.3. Inspect for damage / Look for chemical deterioration / Binder degradation". In Audio Tape Digitisation Workflow. Accessed February 22, 2021.

Description

A brief signal loss caused by a tape head clog, missing magnetic oxide particles, tape defect, or debris on the tape or machine. These factors can reduce head-to-tape spacing and result in the appearance of white spots or streaks on playback. Multiple drop-outs per frame will result in a snowy appearance.

Cause

Tapes kept in dusty conditions will accumulate particulate matter, increasing the risk of drop-out.

Remedy

Flaking/missing magnetic oxide particles are an indication of tape deterioration. This type of drop-out cannot be corrected physically.

Mould

Image source

Are Your Video Tapes Showing Bad Signs of Mould. MultiMedia Select. Accessed February 24, 2021.

Description

Active mould is generally moist while dormant mould is dry and dusty. Mould growths may be white, black, brown or mustard-coloured and usually have a pattered, fuzzy, or thread-like appearance. Mould can cause permanent damage to tapes over time if not removed. Fungus and mould is also a significant health hazard and affected materials should be handled using gloves and masks.

Cause

Storing tapes at high temperature and relative humidity levels can facilitate the growth of mould.

Remedy

Mouldy tapes should be isolated from unaffected materials to prevent cross contamination. Store tapes at a temperature of 24°C in an environment with effective air circulation and less than 50% Relative Humidity. Loose mold can be vacuumed from the tape pack and then the tape should be treated with an appropriate fungicide.

Stretching and breaking

Image source

Figure 20. Wrinkled VHS tape. Caring for audio, video and data recording media. Government of Canada, Canadian Conservation Institute. June 30, 2020.

Cause

Stretching, wrinkling and breaking of video tape usually results from improper handling or use of playback equipment.

Remedy

Stretching can distort the tape signal however data can usually be recovered (with a decrease in signal quality).

Accidental recording

Image source

Record Protection Mechanisms: MiniDV. Preservation Self Assessment Program. Accessed February 24, 2021.

Description

Camera operators can accidentally record over pre-existing footage

Cause

Tape is set to "record mode" when it is inserted into camera or deck

Remedy

Ensure tape is set to "safe mode" before inserting into camera or deck.

Risk assessment

HIGH RISK

Digital video material stored on magnetic videotape is considered to be at high-risk of loss or degradation.
1. Polyester base film used in videotape is considered very stable.
2. Other components of the videotape, including the binder, are considerably less stable and are more likely to be the cause of degradation.
3. Format obsolesce, including lack of well-functioning playback equipment poses an equal or even greater risk than degradation, even with higher quality formats such as Digital Betacam
Archivists should appraise or reappraise digital video material stored on magnetic tape to determine the nature and significance of video elements contained on the tape. See Section 5 of the University Archives Procedure Manual for guidance on appraising sound recordings and moving images.
The archival appraisal should determine whether the video elements have sufficient archival value to justify reformatting and long-term preservation as digital video files.

Related resources

Digitization Handbook:

University Archives Manual

Section 5 - Archival Appraisal - Archival appraisal of sound recordings and moving images

Technology Watch

Technical overview of digital video systems

References

AMIA. "Video Preservation Factsheets." Accessed December 10, 2020.

Bensinger, Charles. "Chapter 6: All about videotape." In The Video Guide, Second Edition, 71-75. Santa Barbara, California: Video-Info Publications, 1981.

Bogart, John Van. "What Can Go Wrong With Magnetic Media?" In Magnetic Tape Storage and Handling: A Guide for Libraries and Archives. Washington, DC: The Commission on Preservation and Access, 1995.

Casey, Mike. "FACET: Format characteristics and preservation problems." Bloomington, IN: Indiana University, 2007.

Gibson, Gerald. D. "Magnetic tape deterioration: recognition, recovery and prevention." Paper presented at the IASA Conference, Perugia, August 26, 1996.

Jimenez, Mona and Liss Platt. "Videotape Identification and Assessment Guide." Texas Commission on the Arts, 2004.

Museum of Obsolete Media. Digital Betacam (1993-2016). Accessed February 8, 2021. Wheeler, Jim. "Videotape preservation handbook." 2002.

Preservation Self Assessment Program. "Videotape: Digital Betacam." University of Illinois at Urbana-Champaign. Accessed February 8, 2021.

Version history

Version	Date	Author(s)	Version Notes

Introduction

Identification

Physical characteristics

Technical characteristics

Storage

Types of damage and deterioration

Drop-out

Mould

Stretching and breaking

Accidental recording

Risk assessment

Related resources

Further reading

References

Version history