Titan6891 wrote in post #16475437
... I still dont know enough how flashes work exactly and dont understand all the technics
You guys use and you use some words in your discussion i simply dont understand ...
Okay.
Aperture: The size of the lens opening that determines how much light reaches the camera's sensor. It's expressed as a ratio, f/2, f/16, etc. The smaller the denominator, the larger the lens opening. It's similar to your iris. In bright light, your iris contracts (f/16). In dim light, your iris expands (f/2).
Shutter speed: The length of time the camera's shutter remains open to let light strike the sensor. A large aperture and slow shutter speed, for the same scene, lets more light hit the sensor than a fast shutter speed and small aperture. The shutter's design limits how fast a shutter speed can normally be used with flash. That is called sync speed. At speeds faster than sync speed, only part of the sensor is exposed to the flash, leaving a dark band in the picture. A feature called HSS (high speed sync), allows taking flash pictures at speeds faster than sync speed by rapidly pulsing the flash for the time the shutter is open. The 568 can do HSS, the 468 can't.
ISO: The sensitivity of the sensor to light. That can be set by the camera automatically or manually by you. It's expressed as a number. ISO 200 is twice as sensitive to light as ISO 100.
Exposure: The combination of aperture, shutter speed, and ISO that together determines how much light is recorded by the sensor. The same amount of light can be read by the sensor with various combinations of those three variables. They are changed for creative reasons and modify the look of the picture. A large aperture shows only the subject in focus, the background and foreground are blurred. A small aperture shows much more of the scene in focus. A fast shutter speed freezes motion, a slow shutter speed shows motion as a blur.
Stop: A measure of exposure. Increasing exposure by one stop doubles the amount of light hitting the sensor. That one stop change can be made by halving the shutter speed, doubling the ISO, or by opening up the aperture from say f/5.6 to f/4.
Bouncing flash: Indoors, rather the firing the flash directly at the subject, more natural looking results can be had by rotating and tilting the flash head at a wall or ceiling (or both) off to the side or behind the camera, filling the room with light rather than directing the flash straight at the subject.
E-TTL and Manual Flash: An E-TTL compatible flash fires a weak pulse of light when the shutter button is fully pressed, the camera's light meter measures the light reflected back through the lens and tells the flash how much light to emit to properly expose the picture when the shutter does open. Manual flash is just that: you set the power on the flash for proper exposure determined by experience or by chimping, looking at the picture just taken on the camera's LCD and adjusting the power accordingly.
Fill flash: Used to augment natural light by filling in shadow areas that would normally appear too dark without flash. For instance, if the sun is behind your subject, a picture taken without flash will properly expose the background leaving your subject dark and featureless. Firing the flash brightens the subject. This is where HSS can be useful because of the higher shutter speeds in bright daylight.
Modifiers: Umbrellas, softboxes, and beauty dishes are used to increase the apparent size of the flash for softer shadows and more natural looking light. Think a sunny day and distinct shadows vs a cloudy day and soft shadows.
