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Camera Mechanism


Aperture is a small opening from which light enters inside the camera. Mechanical diaphragms are used in the camera to control the light rays passes and strikes the image sensor. In-camera, a diaphragm works as irises of eyes. It increases or decreases depending on how much light is needed. Aperture works as diameter opening. In-camera Aperture is black pupils of eyes through which light travel into the eyes.

Brightness and darkness of the image depending upon the effect of the aperture. If the aperture of radius is more, then more light can be passed into the camera. More light will generate more photons which result in a brighter image.

Size of the aperture is denoted by an ‘f’ value, which is inversely proportional to the opening of the aperture.

Following are the equations:

Camera Mechanism


When light rays pass from aperture it directly falls on the shutter. A shutter is a cover or we can say a closed window which is present behind the sensor. So, we can say that between image formation and light there is a shutter. When a shutter is open, light rays fall on the image sensor and image is formed on the array.

When shutter allows longer light rays, then the image appears brighter and when smaller light rays are allowed by shutter then darker image is produced.

Shutter speed

The number of times the shutter get open or close refers to shutter speed.

Shutter time

When a shutter is open and the time taken to close is called shutter time


Both shutter speed and shutter time are inversely proportional to each other.

Following are the equation:

Camera Mechanism


Shutter speed and shutter time make a variety of applications. One of them is given below.

Fast moving objects

To capture a fast-moving object like an image, for example, a car then adjustment of shutter speed and its time affects a lot. So, to capture the image we have to increase shutter speed and decrease shutter time.

When we increase shutter speed many times shutter will open and close means different samples of light will be passed and when we decrease the shutter time then an object is captured immediately and shutter gate is closed.


ISO is used to denote the sensitivity of light to the camera and is measured in numbers.

A camera is less sensitive to light if the ISO number is low and it will be more sensitive if the ISO number is high.

The brightness of the image depends on the ISO number.

The side effect of ISO is that if ISO has increased then the noise in the image is also increased.

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