absorbed partly refracted and partly reflected and only a portion of the energy being transmitted through end 9 of cigarette 2 the signals emitted by photosensors 19 in group 19b are characteristic of the endfill of end 9 and may assume different values due to nonuniformity of the filling along axis 3 of cigarette 2 the signal emitted by each photosensor 19 is compared with a limit value is equal to emitted energy intensity value ie minus a value io comprising a first component corresponding to the quantity of energy subtracted by optical collimating device 15 and a second component corresponding to a safety value in other words value is is slightly below value ie of the energy intensity emitted by emitter 13 for each curve a and b fig4 shows the respective emitted energy intensity values ie1 ie2 and respective values is1 is2 the signals emitted by photosensors 19 in group 19a are rejected whereas each of the signals emitted by photosensors 19 in group 19b if other than zero is compared with a range of threshold values igmin and igmax characteristic of the endfill to determine the acceptability of the endfill of each end 9 endfill threshold values igmin and igmax may be established experimentally for different types of shredded tobacco 8 for different types of wrappings 7 and for different emitted electromagnetic intensity values or may conveniently be established by defining a range about a mean value detected by photosensors 19 in second group 19b relative to a given emission intensity ie and a large number of cigarettes fig4 shows threshold values igmin and igmax relative to emitted energy intensity value ie2.