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"5 tene Similar conditions apply to the asyumetric image 
deformations in radial and tangential direction, which 
according to /1/ vary by the same relationship as under 
(2) with the change of the distance setting. Thus, the 
change of the symmetry point of distortion derived from 
“400. radial components remains smaller than 2,um and 
that of the tangential components smaller thé 
n 4 un. 
The statements on the behaviour of calibrated focal . 
—" length and rotation-symmetric distortion were corrob- 
orated in experimental series. Table 1 shows the result 
^. of one such experimental series. Here, for comparison 
the distortion values obtained for the individual prin- 
cipal distance change have been converted for the case 
~~ Aa' = 0, For the calibrated focal lengths maximum de-— 
.. viations resulted of as low as 0.01 mm Sonparod, with. 
^. the arithmetically. determined. values. 
. 3. Influences on the measuring result: of objects with‘ 
a large depth of field 
When photogrammetry is used for Sosa rine objects ab 8 
close ranges with a large depth of field, inner orien- 
tation is of much greater importance than it is the 
case in aerial photogrammetry, especially when a -. 
two-camera system is employed. - 
The first point to be considered is that distortion EB 
changes in dependence on the depth of field of the obe. 
ject for all object points lying outside. the focussing 
plane (plane of optimum image quality). According to. 
Fig. 4 the maximum distortion change for a depth of. 
focus. of 1 mm is + 3 jum. The boundary values for the _ 
depth of field whIch/correspond to the range of depth 
of focus of + 1 mm have been listed in Table 2 for all. 
distance settings, referred to the focal length 
£ = 99 mm, With Battal data processing by a pomputer 
program such changes, just as distortion itself as well 
.. as other image deformations, can be eliminated suf-  - 
Gi fictentiy Well: on she basis of polynomials 2sscribed. in 
1310 
^. More. er are the effects of. anperteintlos of the 
basic quantities. For the object points lylng.at a. ^  . 
distance y. in one. common vertical.plane parallel to the ' 
… base such uncertainties can be eliminated: with the: help 
of expediently arranged control points by scale gorree- 
tion and parallel avertence,. For object points outside 
|». of this chosen vertical plane one obtains the following: 
| esiduat: errors: | !