Mastering manual exposure
Manual Exposure is when the photographer manually sets the aperture, ISO and shutter speed all independently of each other in order to adjust exposure. This gives them full creative control over the output of the image.
ISO
ISO is the measure of the sensitivity of your camera’s digital sensor to light. The lower the number the lower the sensitivity, the higher the number the more sensitive the sensor becomes. If you are shooting in a low light situation, say a poorly lit room, an ISO setting of 100 will require that more light reaches the sensor than if you were to use a setting of 400, 800, or 1600.
Why does Shutter speed matter?
Just like the shutters on your windows, a camera’s shutter opens to allow light in. The shutter lives just in front of the imaging sensor and the shutter speed is the amount of time it stays open. Aperture and shutter speed work together: Whereas the aperture determines the amount of light that’s coming through the lens, the shutter determines the length of time the sensor will be exposed to that light. When you set the shutter speed – usually measured in fractions of a second (e.g. 1/30, 1/1,000) – you are telling the camera how quickly or slowly to open and close the shutter. A shutter speed of 1/4,000 second is very fast and will let in very little light, while a shutter speed of 1/2 second will let in a lot of light.
What is Aperture?
The aperture is simply a hole within the lens that limits the amount of light that can pass through the lens. By changing the aperture value on your camera, you increase or decrease the size of that hole, thereby allowing more or less light into the camera. Aperture is measured in f-stops, such as f/22 and f/4. The smaller the f-stop number, the larger the opening, and vice versa. So, when you are adjusting the settings, think of the opposite. How large your lens’ aperture can open will depend on your lens. A lens’ maximum aperture will be part of its model name, like a 50mm f/1.8 or a 12-120mm f/4.
White balance
At its simplest – the reason we adjust white balance is to get the colors in your images as accurate as possible.
Once you master manual mode, you will have full controll of the three major points of the exposure triangle: Aperture, Shutter speed and ISO.
The best way to learn — just do it!
When you’re starting out, developing an intuitive understanding of how the different points of the exposure triangle play off one another may seem overwhelming at first, but shooting in manual gets easier over time.