Light Meter Check
With a spot meter, incident meter and gray card check your meters under all
conditions of light. Many meters have different color sensitivity. Compare your
meter readings in different light sources: sunlight, skylight, 2800K, 3200K,
sunset, HMI's etc. Measure incident light with your incident meter. Compare
it with a spot or reflected meter reading of a gray card in the same light which
is an incident reading.
When we did "meter check" on a set (comparing our different meters) the results
were frightening. Spectras never agreed with Minoltas or other meters. MAKE
NOTES about your meters. Avoid light glare reflections on your gray card that
will give you a false higher reading. Make sure the gray card is flat to the
light and not at an angle where the light rays from the source are spread over
a larger area. A card at right angles to a single light would receive no light
at all. Take reflected readings of a card at different angles to a light to
see how this works. This is important when lighting surfaces at acute angles.
An incident reading with a ball receptor can be misleading, but a flat receptor
would be OK.
Some spot meters including the Digital Pentax have internal flare and will read
dark areas brighter than they really are if there are bright areas surrounding
the dark area. Get close to dark objects to avoid false readings, but don't
let your body block part of the light on the area you are reading.
© Copyright 1999-2004 Ron Dexter. All Rights Reserved.