Multiskilling for Television Production

Peter Ward, Alan Bermingham, Chris Wherry

• Publisher: Routledge
• Year: 2000
• eBook ISBN: 9781317657149
• Topic: Media & Performing Arts
• Subtopic: Film & Video

Written by television trainers who run their own courses on Multiskilling, this book offers a comprehensive introduction to the broad range of skills and technical knowledge required in this industry. It details all the essential information you need to know, acting as an on-the-job reference source for everyday use.

For many broadcasting technicians, one of the biggest challenges in recent years has been the transition from a career working in a solo core skill such as camerawork or audio, to acquiring the experience and expertise of a range of production jobs. Many people are expected to work in a number of crafts and to equip themselves with a much wider range of television techniques than had been customary in the past.

Multiskilling has become an integral part of television culture, requiring that new entrants are competent in several specialist production skills. Multiskilling for Television Production concentrates on the techniques associated with news and magazine programme production, where most tecnhical operators are usually employed, but most techniques are shared across the whole spectrum of television and film making.

Anyone baffled by the range and scope of skills to be mastered will find this book invaluable.

1 Television engineering

1.1 Introduction

This section introduces the basic engineering concepts necessary for operational competence in television operations. The depth of treatment is restricted to include only that which is relevant to the role of a multiskilled operator. It is essential that all such operators have an awareness of the basic television system as it affects their operational roles.

The bibliography at the end of this book provides excellent titles for further reading in the engineering aspects of television.

1.2 The video system

The basic television system is shown in Fig. 1.1.

The ‘heart’ of the operational system is the vision mixing console, vision mixer or switcher. All the video sources making up the programme resources are connected to the input of the vision mixer. The vision mixer (operator) selects the appropriate source as required by the Director, and on cue will initiate the necessary transition between sources, i.e. cut, mix, wipe, etc. Normal practice is to include a distribution amplifier (DA) in the feed of each source to enable several isolated feeds to be derived. The extra feeds can be used for monitoring purposes, providing isolated feeds for recording purposes (ISO feeds), etc.

The output of the vision mixing console is also fed to a distribution amplifier to enable ‘programme feeds’ to be available for:

• recording

• feeding to transmission suite for ‘live’ transmission

• monitoring.

Note the abundance of ‘monitoring’ – this is vital so that the video sources can be identified (for remote sources), and checked for picture content and quality. In addition to providing picture monitoring on suitable television screens, there is also a need to check the video signal levels on a waveform monitor (oscilloscope).

The sources available on the vision mixing console may include:

• studio cameras

• caption generator (cap. gen.)

• videotape replays

• electronic slide library

• video server

• graphics

• computer-generated backgrounds

• remote cameras, i.e. remote to studios but within the studio centre complex

• remote contributing source, i.e. outside broadcast or remote studio.

1.3 The television signa

From the above overview, it can be seen that there is a need to be familiar with the television signal, so that routing procedures and monitoring of the signal can be handled with ease.

The best way to approach an understanding of the television signal is first to look at the needs of a monochrome system and then develop this to look at the colour system, i.e. in the way in which the systems have evolved.

Television is the process of transmitting moving pictures. In practice a series of still pictures is transmitted, but at a rapid enough rate to see the change from one picture to the next picture as ‘continuous’ movement. The persistence of vision (a form of image retention) of the eye/brain means that this is possible.

Figure 1.1 Basic television system.

This has a parallel in the film world with film shot at 24 pictures/second. Unfortunately, although a picture rate of 24 Hz is sufficient for conveying movement without ‘jerky’ transitions, the perceived picture suffers from flicker. To overcome this the picture rate needs to be above about 42 Hz. In the film world it would be expensive to shoot at 48 Hz – one would need twice as much film! The solution is a simple one: in the cinema the film projector simply displays each picture or frame twice, resulting in an effective picture rate of 48 Hz. In television the expense of a high picture rate is also prohibitive (see later note on bandwidth) – basically the more information to be transmitted in a second, the more expensive it becomes!

Having defined what is required to be done, we need to establish the basic parameters:

• aspect ratio

• scanning system

• number of lines/picture

• number of pictures/second

• interlace

• synchronization

• television signal

• bandwidth.

Aspect ratio is the ratio of picture width to picture height, the current standard of 4:3 dating back to the 1930s when early high-definition systems were developed. 4:3 was chosen as a compromise on film formats and the availability of suitable display tubes. The trend is towards 16:9 widescreen, with 14:9 as an interim measure.

The first function of the television camera is to produce an optical image of the scene to be televised and convert this to an electrical charge pattern, where the magnitude of the electrical charge is proportional to the ‘brightness’ (more strictly correct ‘luminance’) of the scene. This electrical charge pattern needs to be ‘read-off’ in a regular manner for transmission to the viewer. This is known as a scanning process and involves dividing the ‘picture’ into a number of horizontal lines, then ‘reading’ the electrical charge on each line in sequence, starting at the to...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Acknowledgements
• Introduction
• 1 Television engineering
• 2 Production methods
• 3 Safety
• 4 Lighting and vision control
• 5 Sound
• 6 Multicamera camerawork
• 7 Single-camera camerawork
• 8 Vision mixing
• 9 Television journalism and camerawork
• 10 Video recording formats
• 11 Video editing
• 12 Audio post-production
• 13 Television graphics
• Further reading
• Glossary
• Index