REPORT OF THE WORKING GROUP ON CLOSE-RANGE 
PHOTOGRAMMETRIC SYSTEMS (1968-1972) 
Prof. Dr. H. M. KARARA, Chairman 
Working Group No. 1, Comm. V, ISP 
This fascicle includes the invited papers on the program of the ISP Working Group on 
Close-Range Photogrammetric Systems at the 1972 International Congress of Photogrammetry in 
Ottawa. In a sense, these papers reflect the major strides that have taken place in close-range 
photogrammetric systems since the 1968 ISP Congress in Lausanne. 
One of the major recent trends is the increased application of analytical methods to close- 
range photogrammetry. Through the use of optimum data acquisition system configurations, 
sophisticated mathematical models and advanced analytical techniques, unprecedented high 
accuracies have been achieved. A leading authority in this direction is Mr. D. C. Brown. In his 
invited paper, Brown discussed refinements in close-range camera calibration that have to be 
taken into account in case of moderately large photographic scales and also when one uses highly 
convergent photography which affords superior geometry. Brown gives a general review of a 
number of recently developed special methods of camera calibration tailored to the specific 
requirements of close-range photogrammetry. 
The lack of commercially available photogrammetric cameras capable of meeting the 
wide spectrum of requirements in the various applications of close-range photogrammetry has 
led to developments in two directions : 
   
a) in-house construction of cameras tailored to the specific requirements of individual projects, 
b) use of non- metric cameras. 
In both approaches, the instability of the interior orientation presents a challenging problem 
which has led to the development of novel calibration ideas and nex data reduction approaches. 
In his invited paper, K. Linkwitz reports on current investigations dealing with over- 
coming the problem of instability of interior orientation, and discusses the approach of combining 
camera calibration with object photography. In this approach, camera calibration as well as 
photogrammetric data reduction are undertaken using the same exposure. 
The unavailability of fiducial marks is but one of a number of additional problems that 
have to be taken care of when using non- metric cameras for close-range photogrammetric work. 
Novel calibration procedures and data reduction techniques have been devised to surmount the 
problems connected with non- metric cameras. In his invited paper, O.Jacobi reports on methods 
for solving calibration and computing problems of non-metrical photography. Essentially, he 
undertakes a two-step calibration : first in the optical laboratory where the lens radial distortion 
is determined, and then a calibration of the unstable parameters of the interior orientation in 
conjunction with object photography. Three procedures simplifying the programming of an analytical 
treatment are discussed by Jacobi. 
  
A recently developed method for data reduction, particularly suitable for non-metric 
cameras is outlined by H. M. Karara and W. Faig. It involves direct linear transformation from 
comparator coordinates into object-space coordinates, without the necessity for either fiducial 
marks or initial approximations for the parameters of interior and exterior orientation of the 
camera. In addition, Karara and Faig discuss various calibration approaches for metric and non- 
metric close-range cameras, and review alternative approaches to object-space control. 
The photogrammetric worthiness of some of the 'better'' non-metric cameras (such as 
Hasselblad, Linhof-Technika, Rolleiflex SL.66, etc..) in close-range work has been proven 
beyond any doubt. Attention is invited to Dr. M. Dóhler's presented paper which reports on the 
results obtained from an extensive research project at the University of Karlsruhe. Furthermore, 
   
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