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Menci, Rinaudo 
2. THE TAKING SUPPORT 
The CYCLOP taking apparatus is a calibrated steel bar, mounted on a tripod. A photographic or digital camera support can shift 
along the bar to regular fixed positions of known distances. Bases varying from 10 cm to 1,20 m can be adopted: this allows 
CYCLOP to be used to survey different objects ranging from small artefacts to buildings. 
Once the camera has been fixed onto the support, it can be moved rigidly along the bar, maintaining the parallelism and the co 
planarity of the camera axes. 
The parallelism and the co-planarity of the camera axes of two stereoscopic images is sufficient to guarantee the absence of the y- 
parallax while the knowledge of the base length allows plotting in a local reference system without any orientation procedure. 
Fig. 2: CYCLOP taking system mounted on a tripod (upper left). 
Support of the camera (upper right). Calibrated stop on the bar (lower left). 
The possibility of changing the camera allows one to choose the best camera-lens system for the object to be surveyed; stereometric 
cameras did not allow this freedom. 
On the other hand, CYCLOP cannot assure the normality of the camera axes to the base: this means that cp and co inclinations of the 
taken axis are possible (see figures 3 and 4). If the cp inclination is a degree of freedom that could be useful in order to take stereo 
scopic images of tall objects, the to inclination could cause some problems as far as the knowledge of the taking base is concerned. 
The reference system of CYCLOP (see fig. 3) has X and Y axis parallel the fiducial axis of the camera in the first position and the Z 
axe oriented towards the operator. 
Let us consider the symmetric relative orientation equation [Kraus, 1995]: 
Y 
9 
Py —iidtCj + £ 2 ck 2 +- 1 - 1 cl<p i ~^ 1 ^ 1 d^ 2 + 
C + 
dto 
(1) 
Fig.3: Reference systems and rotations 
The dK] rotation is null. During the movements of the camera along the bar, the fiducial 
axes are fixed; therefore dKi and dK 2 in equation (1) are always null. 
Figures 4 and 5 show the tp and co inclination of the taking axis with respect to a 3D refer 
ence system with the origin in the first projection center, the [XY] plane parallel to the 
fiducial plane of the camera in the first position and the X axe along the base of the taking. 
The to rotation shown in fig. 4 causes the rotation of the [YZ] plane around the X axis of 
the plotting reference system. 
CYCLOP assures the identity of this rotation in both camera positions; therefore , dcp2 in 
equation(l) is null and no y-parallaxes arise in the stereopair. 
The cp rotation shown in fig. 5 causes the rotation of the [ZX] plane around the Y axis of