Abstract: An external flash is attached to a digital camera with an internal flash and is operable selectably in two or three modes. Its control system includes a signal detecting device for detecting a signal for starting emission of light by receiving the detected signal and a single maneuverable device for being handled by a user to select one of these modes.

Abstract: A digital camera containing an internal flash also has an externally attached flash which is adapted to emit light by using as trigger a signal received from the internal flash. A control system for the flash includes circuits for starting and stopping preliminary and main emission of light from the external flash by using as trigger the starting and stopping of light emission from the internal flash and may also be adapted to vary the quantity of light from the external flash for the preliminary emission by changing its waveform. A light screen may be provided to prevent light from the internal flash from illuminating the target object to be photographed by the camera and a light conductor such as an optical cable may connect the internal flash with the external flash. A single knob is operated to switch between two or more different modes of operation such as automatic and manual modes.

Abstract: A base, securely attachable to any type of watertight housing for an underwater camera without causing rotational displacement during its use for underwater photography, includes an elongated main body and a holder plate disposed on the main body which is transversely movable. The base has a protrusion for preventing transverse motion of a pedestal or a leg structure on the housing. A pair of set screws is provided in addition to a fixing screw that is passed through a fixing hole through the base main body to fasten the base to the camera housing. The base main body has a fixing hole for the fixing screw and a pair of elongated holes for passing the set screws so as to be transversely movable. The holder plate has an elongated hole for passing the fixing screw so as to be transversely movable and screw holes for engaging the set screws.

Abstract: A base, securely attachable to any type of watertight housing for an underwater camera without causing rotational displacement during its use for underwater photography, includes an elongated main body and a holder plate disposed on the main body which is transversely movable. The base has a protrusion for preventing transverse motion of a pedestal or a leg structure on the housing. A pair of set screws is provided in addition to a fixing screw that is passed through a fixing hole through the base main body to fasten the base to the camera housing. The base main body has a fixing hole for the fixing screw and a pair of elongated holes for passing the set screws so as to be transversely movable. The holder plate has an elongated hole for passing the fixing screw so as to be transversely movable and screw holes for engaging the set screws.

Abstract: For controlling emission of light from an outer flash lamp having a light receiving part and externally attached to a camera, which may be a digital camera and may be enclosed inside a watertight housing for underwater photography, having an inner lamp which is provided internally and includes a light emitting part, a filter which passes infrared and near infrared light but prevents visible light from passing through may be attached to the light emitting part of the inner lamp or on the housing of the camera. Light emitted from the inner lamp has sufficiently strong infrared intensity and the portion passing through the filter is sufficiently strong to activate the outer lamp. The filter may be substituted with a light intensity-reducing filter for reducing the intensity of incident light thereon with an amplifier added to the light receiving part of the outer lamp such that the light with reduced intensity through such a filter can activate the outer lamp.