The
weather has been great this past week and
not one to pass up such a rare opportunity I have moved my office to the end of
the garden where it is shaded by some
silver birch trees. If it was not for the shade I would not be able to see the
computer screen.
As you know
from previous posts I have become quite smitten with my Zero 6x9 deluxe camera.
It's lack of through the lens metering! Your right no lens, I have had to
revert to using a hand held one. NO! I'm not going to take another camera with
TTL with me. Why load myself down, believe it or not even with a tripod it is
lighter than my standard kit. Besides I don't need the light readings to be
that spot on especially when needing to account for reciprocity.
While
writing this I'm joined by a baby starling. It looks like the one I saved from
the jaws of the cat the other day. The bird seems happy for me to be here as
he/she walks up to and around the chair I'm sitting in looking for local
delicacies. It appears I'm the last thing it needs to worry about.
Two types of hand held light meter |
I have two
types of meter to choose from they are tried and trusted run of the mill units.
The oldest one uses a selenium cell which is a type of photovoltaic / solar
cell. When the front of the meter is exposed to the light it produces a small
current which moves a needle that indicates how much light there is. This type
of meter is batteryless but one of the down sides is in low light situation it
requires a certain light level to read accurately.
The other
light meter is a CdS unit or Cadmium Sulfide cell that has a greater low light
sensitivity. This light meter works by regulating the energy in the battery
rather than producing a current as in the former. With this type of meter it
can suffer from drifting this is where the meter has been shown a bright light
temporarily making it blind. The cell has a memory and can fool you into
thinking the level of light has not changed. It is a good idea to let the meter
read the scene for several seconds to make sure it has read it properly.
Note the starling casting a critical eye over the photographs. |
My light
meters are general purpose, they read reflective light from a fairly large area
of the subject which is about 30 degrees. They round this reading to an average
of 18% ( a mid grey) no matter how dark or bright the scene is. This is where
the zone system ( See Ansel Adams The Negative for more info) comes into its
own or a system of your own to allow for it. I have my own method that works
well with a little bit of intuition thrown in. Well! Most of the time.
Since writing this my CdS light meter has passed away. It will be missed.