Kodak DCS 300 Series User Manual page 152

Strong lighting
In the following situations, ignore the In-focus indicator ( ):
When subjects are located at different distances (for example, animals inside a
cage or a person over a fence), use Spot Area for autofocus (page 6-31), or focus
manually with the clear matte field.
When using a linear polarizing filter or other special filter, such as a soft-focus
filter, focus manually with the clear matte field. (A circular polarizing filter can be
used in connection with the autofocus operation.)
7-20
With a strongly backlit subject, a
bright or shiny subject, or a scene in
which there is a pronounced
difference in brightness, focus
manually with the clear matte field.