Number 2 on my 10 Things Every Photographer Needs to Learn list is aperture. Aperture is the opening in your lens. It controls how much light reaches your sensor. So aperture helps control how bright or dark your image is. It also controls your depth-of-field (how much of your scene is in focus from front-to-back). Because of this dual purpose, I think it’s the most important camera setting to learn and master first.
Aperture is expressed with a number called an f-stop. You usually see it expressed as f/2.8 or f/11.
3. Shutter Speed
Shutter speed is how fast your shutter opens and closes. That speed affects how much light reaches your camera’s sensor, which also affects the relative brightness in your image.
Shutter speed is also one of the most important things every photographer needs to learn because it controls how action is conveyed in your images. Wow, that was a really long sentence. Let me explain, briefly this time.
Fast shutter speeds stop motion. It’s how you can stop a basketball player in mid-air or drops of water in mid-fall. Slower shutter speeds create blur which conveys motion. Slower shutter speeds smooth out water and clouds and create blur in moving objects. We call deliberately using really long shutter speeds long-exposure photography.
Shutter speed is expressed in seconds. Faster shutter speeds are expressed as a fraction of a second, like 1/1000 (1/1000 of a second). Slower shutter speeds use whole seconds, like 2 seconds or even 30 seconds.