question of correlation of OTF with measurement (pointing), a
question which has not yet been favorably answered. A carefully
designed study by a number of laboratories whose prime. concern
is with accuracy of measurement, needs to be conducted. The
emphasis should be practical remembering that where stereo images
are employed the MTF from two parts of the field, obtained from
edge gradient analysis on original film, will be used. A dis-
cussion of all the pros and cons by those who have studied any
part of this problem, prior to selecting the study techniques
would aid in defining the study and avoiding many problems.
It is recommended that a Commission I Working Group on Image
Evaluation for 1976-1980 quadrennuim consider this study. OTF/MTF
studies should continue until national specifications are developed
and used, and good correlation is assured for photogrammetric
optics and instruments.