flash and then activating the main flash underexposure of the subject 16 is prevented provided that the subject 16 is within the flash range typically twelve to fourteen feet from the camera 10 this is especially advantageous when the subject 16 is being photographed outdoors or when an outdoor scene is being photographed and bounce flash illumination is not needed when the subject or scene is sufficiently illuminated by natural light so that artificial flash illumination is not needed the output voltage signal from the photodetector 60 is high which causes the first voltage comparator 62 to produce a low output voltage signal this low output voltage signal does not trigger the main flash scr 28 at the closing of the synchronization switch 70 thus the main flash tube 14 does not fire when the camera shutter button is pressed in addition the low output voltage from the first voltage comparator 62 inhibits the function of the second voltage comparator 64 by changing the reference voltage so that the bounce flash scr 44 is not triggered thus the bounce flash tube 18 does not fire accordingly the subject 16 is neither illuminated by direct flash from the main flash tube 14 or by indirect flash from the bounce flash tube 18 referring now to fig3 an electrical circuit is shown.