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4.2 Measured Results
4.2.1 Typical Results
Figure 5 and 6 show typical examples of the phtogrammetric
camera MTF from our experiments. Data for maximum image height
(0.95) are omitted in these figures.
For H=0, MTF keeps a high value up to 20 lines/mm which is
chose as the maximum spatial frequency for photogrammetric lenses.
Fall of MTF for off-axial imagery is remarkable.
Camera A is chosen as a better example and B is a worse one.
However, quick fall of MTF with respect to image height is common
to both cameras.
4.2.2 Image Height
Based on the above fact the image height characteristics shown
in Figure 7 for Camera C are useful in application.
In this figure, MTF value for 5 and 10 lines/mm is shown as a function
of image height. Curves indicate continuously the fall of MTF
with respect to the image height.
For reference purpose, aerial weight of the image height is
indicated by double thin lines in the figure.
4.2.3 Deviations from Symmetry
Vertical lines in Figure 7 attach to average MTF value show
r.m.s. deviation of each measured value for the four radial directions
from the mean value.
From this fiqure, one finds the order of nonsymmetry by the
length of the vertical lines.
4.2.4 Effect of A.V. Filter
Comparison of MTF with and without A.V. filter is shown in
Figure 8 for the case of Camera D.
Differences between two curves for the same conditions are
+4%, and accuracy of the measuring instrument is about that order.
Effect of A.V. filter in this case is not, therefore, quite visible.
If differences become larger than the above value, then
we can see the effect of A.V. filter in image performance.