is read on a transmission densitometer, and paper is read
paper electronically. Before a densitometer can be used,
it must be checked and calibrated against a reference
standard. To use the meter, you must place the material
to be measured, emulsion-side up, in the light beam
between the source and the photocell. The density
reading is then read directly from the meter.
black-and-white materials, the yellow filter must be in
place. When color materials are read, there are two
different sets of filters that are used. They are Status A
color transparencies and prints. Status M is used to read
color negative film that has an orange mask
manufacturer of the material or are established by the
quality control technician within your imaging facility.
When you are reading the steps on your control strip, be
sure that the emulsion side is facing up and take the
reading from the center area of each step (fig. 10-27).
processed and read on a densitometer are then plotted
on a control chart. The points plotted on the graph
indicate what has occurred in the process at the time the
control strip was processed. Through the use of control
charts, a determination can be make whether the process
is operating normally. As stated before, only selected
steps of a control strip are monitored. For black-
and-white film, the minimum steps monitored are as
follows: base plus fog (B + F) or gross fog, high density,
low density, speed point, and contrast.
(pronounced "bar X"), or average, a top line that
represents the upper control limit (UCL), and a bottom
line that represents the lower control limit (LCL).
Basic Photography Course