Focal Length

Focal length is a measurement in millimeters of the distance from the sensor on the camera’s face to the focus point of the lens face. Different lenses come with different focal lengths to allow a photographer to take close-up or zoomed out from the given subject. Specifically, the bigger the focal length measurement, the more the lens will magnify the subject in the resulting photo.

While lenses with higher focal length measurements tend to be longer, those with smaller focal measurements are generally shorter. For example, think of a telephoto or zoom lens versus a traditional lens: telephoto lenses that significantly magnify their subjects are longer than traditional lenses that represent their subjects in relative proportion to their surroundings.

Consequently, while photographers taking macro photography shots will look for lenses with higher focal length measurements, those taking pictures of landscapes or cityscapes will want to use lenses with smaller focal length measurements.

Manufacturers usually print the exact focal length of a lens on the lens’ mount, the base where the lens meets the camera face.