Relationship between aperture shutter in introduction to photography

There are three parameters that affect camera exposure, namely shutter, aperture and sensitivity (iso). Every parameter of modern digital camera is adjusted in one-third step, and the exposure of each parameter and gear is consistent and interchangeable, which is called reciprocity rate.

The relationship between shutter, aperture and sensitivity is like putting water into a pool. Shutter is the discharge time, aperture is the pipe diameter, and iso is like the depth of a pool. This metaphor is a good understanding of the control of exposure by three parameters. The thicker the water pipe, the shallower the pool, and the shorter the time to fill the pool, and vice versa.

Shutter determines the speed, high-speed shutter can capture high-speed moving objects, aperture determines the depth of field, and large aperture can better blur the background and highlight the subject. Increasing the sensitivity can speed up the exposure (irrigation time), but too high sensitivity will increase the noise particles in the photo. These three parameters are trade-offs, so we should choose the appropriate combination of parameters according to different shooting themes.

The camera has a built-in exposure meter, that is, a scale with a mark. Different combinations are basically normal exposures as long as the photometric scale is in the middle zero, but they are not necessarily the most suitable. It depends on your theme tone, dark tone or bright tone, and increase or decrease the exposure combination appropriately.