made of fig2 fig2 shows two successive film frames f 1 and f 2 and two focused images of the light dot 52 partially obscured by the disc 49 the disc 49 is in respective positions corresponding to horizontal and vertical orientations of the camera during picture taking as shown in fig1 the opening blade 5 includes a light blocking sector 53 located between the led 35 and the light inlet 33 of the light pipe 31 when the blade 5 is moved away from the blade 7 in the direction b to open the shutter 1 and thereby initiate a film exposure the light blocking sector 53 moves from between the led 35 and the light inlet 33 this permits low intensity light from the led 35 to form a focused image of the light dot 52 partially obscured by the disc 49 on the filmstrip f and permits such light to be directed onto the phototransistor 41 to turn the phototransistor on such latter purpose involving the phototransistor will become apparent below in connection with a detailed description of an electronic flash circuit the closing blade 7 includes an integral light blocking sector 55 which in fig1 is shown removed from between the led 35 and the light inlet 33 when after the elapse of an appropriate exposure time the blade 7 is moved toward the blade 5 in the direction b.