Flash The Different Flash Mode
Having seen in a previous article the different types of flash, let us analyze what are the main flash modes available on all reflex cameras or compact high profilo.Principalmente we can divide the whole into four main categories manual, automatic, TTL and Dedicated.
The flash Manual is more complex to manage the flash emits a flash of intensity and well-defined duration http://www.akusewa.com/sewa-led-screen-jakarta. Manually you can act on the flash in order to increase or decrease the amount of light emitted during the flash, change that is not made by increasing or decreasing the power but by acting manually on the flash duration. In case of manual flash it is necessary, in function of the guide number, define the correct opening of the diaphragm and the right distance to the subject.
Automatic The flash emits a flash of light set according to the aperture. The user is then left only the problem to settle down at the right distance from the subject to be photographed. In this mode to be changed it is not the power but the flash duration a sensor in the flash basically calculates how much light is needed to use the diaphragm used by the photographer to photograph the standard distance (as defined in the guide number). When the amount of light has been properly issued, the sensor ends the lightning.
The TTL Flash is the evolution of the automatic flash as the sensor of which is the first part of the camera and not the flash machine. This way you get a definite advantage the measurement of exposure to you through the lens and not to several centrimeti from it (on the head of an external flash, for example) .The flash Dedicated Finally the evolution of TTL as it adds to TTL a huge amount of other features, specifications of the manufacturer of the same.
The Flash mode TTL
Let us now see in detail the TTL mode that a camera can provide a photographer. And in particular those that we see are the TTL flash knots in the case of a digital SLR camera.
D-TTL The sensor mounted in the camera sometimes fails to reflect a sufficient quality of light (especially when the lighting is low). To solve the problem, the camera performs exposure metering using the pre-flash light that is reflected from the shutter curtain before the exposure reading of the scene. the end of exposure is detected by the camera’s exposure meter. This system is called the D-TTL metering system. The pre-flash light is one or more bursts (usually are more than one) emitted from the flasher, the intensity of which is lower than that of the main flash.