How does camera exposure work? - General Information

In this lesson, we will explains how Digital Camera exposure works as quickly as possible (we will see it in details in the next lesson), so first we have the SUN which creates light, that reflects  upon objects in our world, then you have camera that tries to capture this light, the light enters the camera through a camera lens, and there are 3 basics functions in the camera that help to control light so that you get a proper exposure (a photo that isn’t too dark or too light), in this article we will talk briefly about this 3 functions and how they control light :

1. Aperture (f-stop number):  

The diameter of a hole inside your lens, the bigger the hole, the more light that enters, the smaller the hole, the less light enter, but the confusing thing is that the small f-stop number, represent a larger opening, for example going from f/1.4 to f/2 decreases the size of the aperture, and therefore allows less light into the camera.

If it is very bright outside, you may have to decrease the size of the aperture, but that is actually increasing the f-stop number.

2. Shutter speed :

Cameras have a shutter that opens and closes to allow light into the body of the camera, the faster this open and closes, the less light comes in, even if one second may seem fast to you and me, but that is very slow for our camera shutter speed, and that means that a lot of light will be entering your camera.

Shutters can go faster as 1000 per second, and this fast shutter allows us to capture fast moving objects like a hummingbird.

So Remember, a longer shutter allows more light in, so you might have to slow down your shutter speed if it is too dark outside.

3. ISO : 

It is basically the sensitive of your camera sensor, a digital wonder that captures the light and turns it into digital photo; The higher the ISO its means it is more sensitive, and makes us brighter photos.

The negative side of raising your ISO when it is dark is that it comes with green, so the higher your ISO, the more greeny your photo will be.
Depending on your camera, you will be able to raise your ISO higher without getting green.

THE ART OF PHOTOGRAPHY IS BALANCING BETWEEN THIS 3 FUNCTION APERTURE, SHUTTER SPEED AND ISO, TO GET PROPER EXPOSURE

This Free online photography course dives deeper in each one of these functions, but hopefully, now you little understand more about your camera, and how to use the manual function to get a proper exposure.