How To Calculate Optical Zoom

Optical zoom refers to a camera’s capability to bring the subject nearer without the necessity of moving closer physically. This is accomplished through the use of lenses that have the ability to adjust their focal length, enabling the camera to take pictures from various distances. In this piece, we’ll delve into the methodology behind calculating optical zoom and its significance in photography.

What is Optical Zoom?

Optical zoom is a feature of cameras that allows you to get closer to your subject without physically moving closer. It is achieved by using lenses that can change their focal length, allowing the camera to capture images at different distances. This means that you can take pictures of objects that are far away without having to move closer or use additional equipment.

Why is Optical Zoom Important?

Optical zoom is important for photography because it allows you to capture images that would be difficult or impossible to capture without it. For example, if you are taking pictures of wildlife or sports events, optical zoom can help you get closer to the action without disturbing your subject or putting yourself in danger. Additionally, optical zoom can help you take better pictures by allowing you to control the composition of your shots and capture more detail.

How to Calculate Optical Zoom

To calculate optical zoom, you need to know the focal length of your camera’s lens. The focal length is the distance between the center of the lens and the point where light rays converge. To find the focal length of your lens, look for it in the specifications of your camera or on the lens itself.

Calculating Optical Zoom

Once you know the focal length of your lens, you can calculate optical zoom by dividing the longest focal length by the shortest focal length and then multiplying by 100. For example, if your camera has a focal length range of 24-70mm, you would divide 70 by 24 and multiply by 100 to get an optical zoom of 291.67%.


Optical zoom is a valuable feature for photographers who want to capture images at different distances without physically moving closer. By understanding how to calculate optical zoom, you can make informed decisions about which camera to buy and how to use it to take better pictures. Remember to always read the specifications of your camera and lens to ensure that you are getting the most out of your equipment.