When a camera captures an image, it does not record light from every object going in all places simultaneously. Instead, a camera uses a combination of lenses, apertures, and sensors to selectively gather light from a specific direction and focus it onto the image sensor.
The camera lens plays a crucial role in capturing light from a particular scene. The lens has a specific focal length and aperture size, which determine the field of view and the amount of light that enters the camera. When you press the shutter button, the camera opens the shutter, allowing light to pass through the lens and onto the image sensor for a brief moment.
The lens focuses the incoming light onto the camera's image sensor, which is composed of an array of photosensitive elements (pixels). Each pixel records the intensity and color of the light that falls on it during the exposure. By combining the measurements from all the pixels, the camera forms a digital representation of the scene, which we perceive as an image.
However, it's important to note that the camera's lens has a limited field of view, and it captures only the light that enters through the lens at a specific angle. Light that doesn't enter the lens from that particular direction does not contribute to the captured image.
In other words, a camera records light from a limited portion of the scene, defined by its field of view and the position and orientation of the lens. The light that enters the camera from other angles or objects outside the field of view is not captured in the resulting image.
This is why, when taking a photograph, you need to frame your subject within the camera's field of view to ensure that the desired objects and angles are captured in the image.