MTF 
Average 
% r.m.s. deviation 
10 lines/mm" 
0.5 ines/mm S 
Ce 
v 
| | 1 l | 
| 0 0.2375 0.475 0.7125 0.95 
| Image Height 
Figure 7. Image Height Characteristics of Camera C 
5. CONSIDERATIONS 
5.1 Measuring Range in Spatial Frequency 
We started in our experiments with 50 lines/mm as the maximum 
frequency for photogrammetric cameras, however, our present recommendation 
of maximum frequency is 20 lines/mm from a practical point of view. 
This frequency seems not high enough for on-axis (H=0), but quite 
enough for off-axis as shown in Figure 5 and 6. 
5.2 Choice of Fixed Frequencies for Evaluating Image Height 
Characteristics 
Since we found image height characteristics are very important 
and also useful for photogrammetric camerd, we need to choose one or 
two fixed frequencies as parameters in Figure 7 and 8. 5 lines/mm and 
10 lines/mm could be recommended as the reasonable fixed frequencies.