CONVERGENT VERSUS VERTICAL PHOTOGRAPHY, SCHERMERHORN 117
a. One convergent camera for standard angle $ 30,000
One wide-angle 9 X 9 inch 15,000
One Universal Autograph for convergent photography 50,000
One precision plotter of convergent photography 30,000
One rectifier 15,000
Laboratory and miscellaneous 40,000
Residual working capital 20,000
200,000
In the second case for vertical photography:
b. One standard-angle camera 12,000
One wide-angle camera 15,000
One Universal plotter 50,000
One precision plotting instrument 25,000
One enlarger 8,000
Laboratory instruments and miscellaneous 40,000
Working capital 50,000
200,000
In case b. they can use two additional plotting machines for these $ 50,000 and have
twice the plotting capacity compared with convergent photography. Therefore, in the
opinion of Prof. Kasper, not only the point of precision, but also the cost of investment
and the clumsiness of the convergent method play a role when approaching a judgment.
After all these considerations we feel a need for figures which allow an overall
evaluation of production time and precision, in particular of convergent photography.
We expect that this will be published by our Commission IV at the London Congress. In
the first place we have results of the experiments of Subcomm. IV.1 of the LS.P. on the
test field Monti di Rivoira, organized by Dr. H. Härry in cooperation with Dipl. Ing. A.
Pastorelli of Lugano. Photography was carried out with:
Wild RC Ta 10/15 em scales 1 : 7,000 — 1 : 11,000
Wild RC 5a 11.5/18 em scales 1:6,100 —1: 9,600
Zeiss 2 X RMK 21/18 cm — 27^ scales 1 : 6,200 —1 : 8,100
Photogrammetric measurements of machine coordinates X, Y, Z were carried out in
20 different centres of 9 countries in 25 separate series of measurements. These coor-
dinates were transformed into geodetic coordinates by the Swedish Society of Photogram-
metry and the differences (X—x) (Y—y), (Z—z) were computed. This society sent me
through Byrâdirektôr S. G. Môller a report about these tests. Mr. Môller authorized me
to use the following table in this panel discussion. This table I derived from the report
by reducing the mean square errors in the terrain to values in the plane of the negative.
We used for this the flying height which, in the report, is indicated with “Flight height
in the middle” and the corresponding “picture scale in the middle”. The results for the
m.sq. value of the point errors in the plane of the negative expressed in u are:
i. ; Time for orientation | M.sq.error
Strip Scale | Camera ;
per model | in u
I 1 : 9000 RCT - | 3h14 174
I 1 : 8000 RC 5a 3.20 | 27 u
III 1 : 7000 | 2*XRMK | 61.46 | 34u
