Focal Length

To unlock photography, you must have a focal length as a key! It seems to be a significant characteristic in buying a lens for your camera.

What does Focal Length mean in terms of Photography?

A definition of Focal Length: the focal length is defined as the measurement of an optical distance from a point of convergence of all rays to produce a sharp image of an object to the digital sensor at the focal plane in the camera. The focal length is expressed in millimeters (mm).

It does not depend on the length of your lens/lenses with different sizes that could have the same focal lengths. The focal length of the lens gives you the basic idea of how “zoomed in” your photos will be. The higher the number, the greater zoomed your lens will be.

Short focal length (for example, 18mm) gives a broader view and large area, while longer focal length (for example, 55mm) will give a smaller angle, and the object appears to be large. Prime lenses come with a fixed focal length while zoom lenses have an adjustable focal length. So, focal length describes the angle of view of the lens. In other words: how much of the scene the lens captures.

Where can you find the Focal Length of a lens?

The focal length can be found on the barrel of the lens. A simple example: a 50mm lens has a focal length of 50mm.

Focal Length Recommendations

• For landscape photography and/or architecture photography, a wide-angle lens with a focal length of 35mm or less will be used.
• For portrait photography, a camera with a focal length ranging from 70-135mm would be great because cameras with other focal lengths will misrepresent the facial feature. The 50mm lens is also great for portrait photography.
• For landscape/sports photography or wildlife photography, a telephoto lens with 70mm or more focal length would be a great catch.