The latest on-line available version of the IPACO software is version 4.86, which
results from a development with a financial support from CNES/GEIPAN, introducing
the management of the last geometrical parameter that enables defining accurately
the shooting conditions: the rotation of the camera around the line of sight.
Up to now, this parameter had been ignored, which means that all Photos were assumed
to be « vertical » (that is to say, more accurately, that the vertical axis of symmetry
of the Photo’s frame, in its original position in the camera’s focal plane, was supposed
to belong to the vertical plane containing the line of sight).
This « omission » was in fact irrelevant for most of operations allowed by the IPACO
software (image processing, radiometric or geometric measurements, etc.), but it
had important consequences for two particular functions (in the present state of
the software), which could provide inaccurate results, sometimes even no result at
all, with a non vertical Photo:
This function can only detect a thread in a Photo if this appears vertical ± 30°
on this Photo
The superimposing of a Photo and the corresponding sky background, provided by Stellarium,
is only correct if this Photo is vertical.
The new Rotation of the camera parameter may be introduced into the Technical data
associated with a Photo in 3 ways:
automatic while importing the Photo, when the EXIF metadatum « Image orientation
» is present (multiple of 90°)
manual and accurate, as for all other Technical data, introducing its value in degrees
(Camera/Technical data menu)
Manual and empirical, validating the currently displayed Photo’s verticality, after
using the standard interactive Rotation command (Camera/Technical data menu ).
When a Photo is displayed, the possible associated Rotation of the camera is automatically
compensated so as to always display the Photo vertical on the screen.
When using the Vertical thread function or the Planisphere function, the Photo is
always displayed vertical on the screen, and all subsequent computations are automatically
The updating operation for the analysis reports presented in the Sample galleries
has been continued. In fact, some reports had been written before the IPACO software
(or some of its functions) was available. Without modifying the results nor the conclusions,
the new writings show how those same analyses may be performed using IPACO and CamCAT.
Two new analysis reports, correcponding to lens flares, have been updated in the