Which is better for fill light and flash _ comparison of flash and fill light

LED light board We generally call it LED fill light. It can be seen from this name. It can only be used to fill light, but it can't be used as the main light source.

What is the fill light and what is the main light source? Fill light means that, for example, when the backlight is shot, the light on the face is too weak. We use a little light to illuminate it and make up for its light. This is called fill light. The main light is the main illumination source in the whole picture.

The LED fill light uses the LED light-emitting diode to fill the object. The LED light is generally used on a camera phone or a digital video camera because of low energy consumption and high brightness. Since the brightness of the LED light-emitting diode is much lower than that of the real flash, it can only play the role of "filling light". Some mobile phones now use the same flash as the camera, such as Sony Ericsson's K790c, which uses a xenon flash, which is better than the LED fill light, but can't be used as a flashlight like an LED.

The principle of Xenon flash: Xenon flash, also known as high-intensity gas discharge flash. The Xenon flash lamp consists of a xenon bulb, a transformer ballast, and an insulated wire. It uses a special helium gas to fire the discharge in an ultra-high voltage state. The working principle is that after the trigger of the camera is triggered, the 12V power supply is raised to a high voltage pulse voltage of more than 20,000 volts in an instant through a transformer, and the helium gas in the xenon bulb generates a strong 6000K--10000K color temperature in the arc. Light, the color is crystal white diamond with a little purple blue.

When the shutter is pressed, the shutter feeds back a signal to the CPU, and at the same time, the CPU synchronously outputs a control signal trigger circuit to the triode for flashing. Then the transistor is turned on, so that the trigger capacitor begins to discharge, and a pulse current is generated at the primary of the transformer. This current causes the secondary of the transformer to generate a high voltage of nearly 4000 volts, which excites the internal xenon ionization of the flash lamp and conducts. The electric energy stored on the capacitor is instantaneously converted into light energy by the discharge of the flash tube to complete a flash.

Early flash lamps have a very short life, and some magnesium tubes can only flash once. According to industry standards, at the time, 10,000 times, the real life expectancy should be far less than 10,000 times. The current flash, after technical transformation, should have an increased life expectancy.

The principle of LED flash: LED does not emit light through the internal electronic transition of the atom, but by applying a voltage across the PN junction of the LED, the PN junction itself forms an energy level, and then the electron jumps at this energy level. Change and produce photons to illuminate. The service life of qualified LEDs at rated power should reach about 100,000 hours. If the mobile phone is designed to use the LED's drive current beyond the rated current, the LED life will be greatly reduced to thousands or even hundreds of hours.