What Is ISO in Photography?
An f-stop is the number used to describe the size of the lens aperture and how much light enters the camera. It is written as f/number (such as f/1.8, f/4, or f/16). A lower f-stop means a wider aperture that lets in more light, while a higher f-stop means a smaller aperture that allows less light. f-stops are fundamental to controlling exposure and the overall visual style of a photo.
How Do f-Stops Affect Exposure?
Each full f-stop change doubles or halves the amount of light reaching the sensor. For example, moving from f/4 to f/2.8 doubles the light, making the image brighter. Moving from f/4 to f/5.6 halves the light, making it darker. f-stops work together with shutter speed and ISO to balance exposure in different lighting conditions.
f-Stops and Depth of Field
f-stops also control depth of field, or how much of the image appears sharp. Lower f-stops create a shallow depth of field, ideal for portraits and subject separation. Higher f-stops increase depth of field, keeping more of the scene in focus, which is useful for landscapes, architecture, and group photos.
When Should You Change Your f-Stop?
Use lower f-stops in low light or when you want a blurred background. Use higher f-stops in bright light or when you need sharpness across the frame. Understanding f-stops helps photographers make creative and technical decisions with confidence.
