The present invention relates a powderous formulation comprising vitamin E, which can be produced easily and which can be used in many fields of application, but mainly in beverages. A xenon lamp in a light source emits illumination light. The clamp member is pivotally coupled to the base member and has at least one clamp-fastener orifice. The lens barrel extending and retracting mechanism prevents displacement and tilt of the lens optical axes of the first lens group and the second lens group, maintaining optical performance and reducing the size of the lens barrel in the housed position.