Focal Length
As mentioned on the Equipment and Gear page under lenses, focal length is part of what a lens is defined by. By technical definition, focal length is the measure of distance (in millimeters) between the optical center of the lens and surface of the image sensor. It is the distance from where the light rays converge to the sensor – or in other words, the lens length. Focal length determines the field of view which is how wide or narrow an image will produce. The shorter the focal length, the wider the field of view, less magnification, and less zoom. The longer the focal length, the smaller the field of view, more magnification, and more zoom.
Aperture
Aperture refers to the opening in a camera lens through which light passes through to reach the image sensor. It controls the amount of light that enters the camera and influences the depth of field in a photograph. The depth of field is the ability to blur out the background and leave a subject in focus. The scale of measuring aperture is in units called stops. “F” is a ration of focal length and aperture. The smaller the number, the larger the maximum aperture and vice versa. For example f2.4 is a larger opening than f5.6. The widest aperture collects the most light, so in dark environments, you will want to let in more light, therefore having a wider aperture or a lower “f-stop”.
Shutter Speed
Shutter speed determines the length of time the camera’s shutter remains open to expose the image sensor to light. It controls the amount of motion blur in the photo and affects the exposure of the image. It is measured in fractions of a second such as 1/250s or 1/1000s. A fast shutter speed (like 1/1000s) freezes motion and is ideal for capturing fast-moving subjects like sports or wildlife. A slow shutter speed (such as 1/30s) allows for longer exposure times which can create motion blur effects such as flowing water or light trails in night photography.
ISO
ISO measures the sensitivity of the camera’s image sensor to light. A higher ISO setting increases sensitivity, allowing you to shoot in low-light conditions, by may introduce more digital noise (or grain) to the image, decreasing quality. When selecting ISO, consider the available light and desired image quality. Trial and error is the best way to adjust. Take a photo, see where changes need to be made and increase or decrease accordingly.