F. and S. Marriott 140 Newbegin, Hornsea, England, HU18 1PB

May 2010. Stephanie died peacefully on 19th April after a short stay in hospital. She had been suffering from acute cervical cancer. Fred will continue to run the business to the best of his ability. The web site is slowly getting under control again as he tries to take over some of Stephanie's responsibilities, and learns some of the mysteries of Dreamweaver.

Metering Systems

by Stephanie Marriott

Introduction

Types of meters

Meter Display

Uncoupled Meters

Coupled Meters

Exposure Values

Introduction

While modern cameras routinely have fully automated exposure control, older cameras offer a variey of metering solutions ranging from no metering at all through to automated metering.

This piece attempts to explain some of the terms used when describing older metering systems but please note, it is only concerned with cameras with built-in meters.

Types of meters

Most older cameras have either a selenium cell meter or a CdS meter. The CdS metering system requires a battery - check that a suitable battery is still available. A few cameras have an extinction meter which requires no batteries but is difficult to use and possibly less accurate. For more about extinction meters, see the Leudi extinction meter instructions, which give a good explanation of how one is used.

Meter Display

The majority of older cameras with meters have a match-needle meter. This will have either a display window on the top plate or a viewfinder display, and sometimes both. The display will show a notch or needle and a moving pointer. Match the pointer to the fixed marker to get the correct exposure or a correct exposure reading.

Uncoupled Meters

An uncoupled exposure meter means that the meter reading has to be transferred from the meter display to the camera aperture ring and shutter manually. On some cameras the meter reads in exposure values (also called light values), which are set on the shutter.

Coupled Meters

A coupled meter has a linkage between the meter and the camera apertures and/or shutter speeds so that when the meter is set, the settings are automatically transferred. For an example of how to use a camera with a coupled meter, see Voigtlander Vito CLR instructions.

Exposure Values

Exposure Values were an idea which appeared on many cameras of the mid-fifties and after.

A camera with an exposure value shutter has a linkage between the aperture ring and the shutter speed ring and a new scale, the exposure value scale. The linkage can be disengaged, usually by pulling one ring gently away from the other, to set a new exposure reading. This is done using the EV scale.

After that, as long as the light stays constant, all that is required is for the desired shutter speed or aperture to be selected; an increase in shutter speed will automatically bring about a reduction in aperture so that the amount of light falling on the film remains constant. Similarly, increasing the aperture causes a reduction in shutter speed.


Other information

Advertisement (1939)

Top of Page

Photographic Pages

Advertising

Articles

Book Reviews

Catalogue

Classic Camera Magazine

F.A.Q.

Instruction Books

Links

Pieces

Shop

Spares and Repairs

We Buy

Useful Pages

What's New? - with details of recent updates to the Marriott site

Site Contents

How to Contact Us

Catalogues

Photographic Equipment

Model Railway Catalogue

Book Catalogue

Stamp Catalogue

Google

Web www.marriottworld.com

http://www.marriottworld.com/metersystems.htm (C) F. and S. Marriott