Sequence viewing > Photographic Exposure - Resource - © Lloyd Godman

Correct Exposure - Reading photographic exposure - Guessing the exposure

In the early days of photography it was quite difficult to calculate the exposure - and many photographers utilized and educated guess -

Even today it is useful to be able to guess the exposure in an informed manner - I know photographers who can do this to about 1/2 a stop within a very wide range of lighting situations.

Rather than rely entirely on the electronic metering system to calculate the exposure its is useful to have an understanding of the approximate exposure for a subject - If there is a problem with the exposure system in the camera - perhaps the battery is flat - and the combination of shutter and aperture do not seem appropriate for the subject - you can pick up the mismatch and check it.

There is always some sense guessing exposures before using a light meter and comparing the difference. This gives the photographer an ever increasing experience and can help pick up problems like setting the ISO wrongly or a flat battery. So, with much practice, even in a wide range of lighting situations, it is possible to guess light intensities and work out some kind of exposure that will produce a negative and will allow us to make an acceptable print - the more you get in the habit of making a mental note of the exposure the more experienced you will become.

Exposure Guide

For sometime through the 1960s and 70s information was printed on a film packet as a guide to the correct exposure that acted as a rough guide for exposing that film - similar to the diagram below.   
 

 


Exposure guide refers to HP5 rated at 400 ASA. Set shutter speed at 1/500. Then set lens aperture as shown.

However what is really needed is an accurate way of reading the intensity of light and translating the reading into aperture f stops and shutter speeds relative to the film ISO or ASA. This is done with a light meter.

Historic lightmeters

 

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