How do you choose the right lens for your camera and camera module?

Sometimes, when customers buy camera modules from us, they are unsure which lens to use. Although there are many theoretical resources, articles, and even calculators that teach people how to choose the right lens, they still feel confused, or even more bewildered, after reading them.

In fact, the type of lens you need largely depends on where you want to install your camera/camera module. Do you want to mount it in a room, office, car, large factory, open backyard, street, or inside a building? Different locations and different viewing distances require drastically different lenses. So how do you choose the right lens from hundreds of different options?

Many factors need to be considered when choosing a lens, such as focal length, aperture, lens mount, sensor size, angle of view, lens construction, and optical length, etc. However, this article will focus on one factor, which is also the most important factor when choosing a lens: focal length.

A lens's focal length refers to the distance from the lens to the image sensor when the subject is in sharp focus, usually measured in millimeters (e.g., 3.6 mm, 12 mm, or 50 mm). For zoom lenses, both the minimum and maximum focal lengths are typically specified, for example, 2.8 mm to 12 mm.

Focal length is measured in millimeters. For reference:

Short focal length (e.g., 2.8 mm) = Wide angle of view = Short viewing distance

Long focal length (e.g., 16 mm) = Narrow angle of view = Long-distance viewing

The shorter the focal length, the larger the area the lens captures; conversely, the longer the focal length, the smaller the area the lens captures. If photographing the same object from the same distance, as the focal length decreases, the apparent size of the object decreases; as the focal length increases, the apparent size of the object increases.