1 The Director of Photography – an overview

Exposure meters 103
flicked over one frame to take a reading when the camera is not running.
In practice, both methods are very accurate and reliable.
These meters work very well on an average outdoor scene, especially
if the camera is pointed down to exclude the sky, a reading is taken and
set, and the camera is then tilted up to the original composition.
Their disadvantage is that they make no allowance for any dramatic
decisions from the cinematographer, since they can only work on
averages.
Reflected light meters
Reflected light meters work in a very similar way to built-in meters –
in fact, they are more or less a hand-held version of the same. Being
hand-held, they do give the cinematographer more control, as they
can be pointed at different parts of the scene to analyse the various
brightnesses within that scene.
Perhaps the most common reflected light meter is the Weston Master.
This meter, with some improvements, has been around for many years.
Unfortunately, even in its latest version, it is not very sensitive and can
only really be used for outdoor photography. Nevertheless, as it is a
classic of its kind it is worth considering.
It has a grid that may or may not cover the meter’s cell, giving two
brightness ranges on the meter. As you cover the cell with the grid, a
new scale comes before the needle automatically, giving you the correct
read-outs for the two ranges. An Invercone attachment can be
added to the Weston to turn it into an incident light meter.
Reflected light meters can be pointed at an 18 per cent grey card to
give an average reading of the scene and will then behave very similarly
to incident light meters.
Incident light meters
As you would expect from their name, these meters measure the light
incident to the scene – that is, the light falling onto the scene. They do
this, in the main, by having a white dome over the meter’s cell that integrates,
or adds together, the light from all directions in front of the meter.
This dome is usually referred to as an integrating or photo sphere.These
meters are especially good for exposing reversal films. The dome does
tend to collect too much light from the sky, so you will often see photographers
holding their hand above the dome to shield it from this effect.
Incident light meters are also very good at measuring brightness
ratios, especially those where the dome can be replaced with a flat
white plate, making the meter much more directional.
An even more sophisticated integrator is the Weston Invercone
attachment for the Weston meter. Here the integrator is not a simple
dome but a hollow white plastic ring with a dimple in the middle. This
has been very carefully designed so that there are exactly the same
percentage areas of plastic facing each direction as has the human
face.Thus, one gets a very accurate exposure reading for photographing
a Caucasian human being. If you were foolish enough to take an
Invercone apart, you would find that between its two top inner and
outer surfaces there is a small piece of paper.This is in there to reduce
slightly the effect of overhead light on the subsequent reading, otherwise