A composition containing a polymer having a structural unit represented by the following formula and a structural unit represented by the following formula, and a fullerene with a carbon number of 70 or more or a fullerene derivative having a fullerene skeleton with a carbon number of 70 or more:wherein, Q, R, R1 and R2 each independently denote a hydrogen atom, and so on. When a power switch is turned off, a taking lens retracts within a camera body, and a barrier drive gear is rotated by a motor to extend a second coil spring so as to force the lens barrier to move to a closed position from the open position at the moment that tensile force of the second coil spring rises beyond that of the first extension spring. According to various preferred embodiments, the laser produces and output above about 50 wattscm2 at a repetition rate above about 15 MHz and exhibits a pulse duration below about 10 picoseconds. The resetting means can be used to set the default password as the reference password if the user forgets the originally input password.