TM 5-6675-319-14
7-3. TECHNICAL PRINCIPLES OF OPERATION.
7 - 3 . 1 G e n e r a l . Rarely can aerial negatives be used for the assembly of controlled
photomosaics without first passing through a rectification process whereby their
scale is corrected and the effect of camera tilt removed.
T o f u l f i l l a l l r e q u i r e -
ments demanded, five freedoms of adjustment are necessary.
The five freedoms of
adjustment are:
M a g n i f i c a t i o n
T i l t
Rotation of Negative in Its Plane (Swing Drive)
Negative Displacement Transverse to Tilt Axis (Y-Drive)
Negative Displacement Parallel to Tilt Axis (X-Drive)
a. Magnification.
The magnification adjustment controls the scale of projec-
t i o n .
I f t h e n e g a t i v e s a r e f r e e f r o m t i l t , i t i s o n l y n e c e s s a r y t o e n l a r g e or
reduce them in order to obtain prints that possess the correct scale.
b . T i l t . T h e t i l t a d j u s t m e n t c o n t r o l s t h e a x i s o f i m a g e p r o j e c t i o n a n d
produces a projected image from which the tilt of the negative is removed.
7-6
