The generally great geographical separations would also lead to
complex standards if an attempt were made in this direction. The simple requirement that each should
stand alone leads to simpler internal calibration standards which, in the long
run will certainly prove most suitable.
Deficiencies under consideration that are correctable fall
into two general categories - panel
errors and matchline errors. Panel
errors include inequality between panels of average panel brightness or color
and also distribution of light and color within a panel. Matchline errors are
not so simply divided into categories, which accounts in part for the extreme
difficulty in controlling matchline appearance. These also involve distribution
of light and color within the matchline area, but the matter is further
complicated in the presence of even slight panel imbalance. In both panel and
matchline errors, camera, printer and projector may be involved. Processing of
negative and positive has been excluded at this time because the techniques
used have made this a consideration too insignificant to be seen in the presence
of other errors, although the characteristics of film do lead to certain kinds
of trouble which can be controlled only with great difficulty and complexity.
This will be discussed later.
Considering first the irregularities that may occur within a
single panel we find sources of error in all three pieces of equipment. Since in a single panel taken alone this
type of error is generally of little consequence, it is also necessary to show
how this affects a composite picture.