46 
7able 6. Correlation Coefficients. Pentax 
*0 
3>0 
c 
*0 
1.0000 
—0.0611 
0.0376 
1.0000 
0.0184 
C 
1.0000 
not vary significantly, exept for y 0 and infinite focus when the variation is al 
most significant. The co-ordinates of the principal point at 10 m and at infinity 
do not differ significantly. 
The change of the camera constant is assumed to be according to Abbe’s 
lens formula using the camera constant for focus on infinity as focal length. 
If c is the camera constant for 10 m we obtain 
11 1 
56.58 ~ ~c + 10 000 
c — 56.902 mm 
This value does not differ significantly from the mean of the camera con 
stants for 10 m focus, 56.846 mm, as this has a standard error of 
0.074 /1/3 = 0.043 mm. 
The radial distortion of the six pictures and the corresponding standard 
errors are given in Table 5 and Fig. 11. As can be seen in the table the variation 
of the radial distortion between different pictures is not significant for any 
radius. 
The residuals after the adjustments of the image co-ordinate measurements 
follow a normal distribution according to a ^ 2 -test for all pictures except one 
that shows an almost significantly different distribution. See Table 19. 
From Table 4 we estimate the following co-ordinates for the principal point. 
Their standard errors are estimated from the variance between pictures, which 
then include the variation that is obtained when the camera is used for photo- 
grammetric measurements. 
x 0 = 0.048 mm s X o = 0.013 mm 
yo = 0.265 mm s y o = 0.032 mm 
The camera constant for infinite focus 
c = 56.579 mm s c — 0.011 mm 
and for 10 m focus 
c = 56.846 mm s c — 0.043 mm