We use the Slovak and Czech video meteor observations , as well as video meteoroid orbits collected in the CAMS , SonotaCo , EDMOND and DMS catalogues , for an analysis of the distribution of meteoroid orbits within the stream of the Geminids and of the dispersion of their radiants . We concentrate on the influence of the measurement errors on the precision of the orbits obtained from the video networks that are based on various meteor-detection software packages and various meteor orbital element softwares . The Geminids radiant dispersion obtained from the large video catalogues reaches the dispersion of the radio observed Geminids , wherby the diffused marginal regions are affected mostly by meteoroids with extreme values ( small or large ) of the semi-major axes . Meteoroids of shorter semi-major axes concentrate at the eastern side of the radiant area and those of longer semi-major axes at the western part . The observed orbital dispersions in the Geminid stream described by the median absolute deviation range from 0.029 to 0.042 \mathrm { AU ^ { -1 } } for the video catalogues . The distribution of the semi-major axes of video meteors in all the databases , except for the Ondřejov ( Czech ) data , seem to be systematically biased in comparison with the photographic and radio meteors . The determined velocities of the video data are underestimated , probably as a consequence of the methods used for the positional and velocity measurements . The largest shift is observed in the EDMOND and SonotaCo catalogues . Except for the measurement errors which influence the analyses and their interpretations , we also point out the problem of the uncertainties of the numerical integration procedures that influence the simulations ’ results . Several experimental integrations of the Geminids parent asteroid , which we performed from the present to the past and then back to the year 2015 , showed that a complete reproduction , including also the mean anomaly , is only possible for a time span of about 2700 years .