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What is a camera lens? Before starting a videography or photography journey, this is one question that everyone is bound to ask.  Therefore, let’s try to break it down to its simplest form. A camera lens is an equipment that contains one or more lens elements designed to process and focus light rays on a camera’s sensor. And although this sounds direct enough, its design is a complex process best left to professionals. This article will also answer some “what” questions while explaining lens basics and construction details. Enjoy.

Lens Terms and Basics Explained

The primary function of a camera lens is to bend light and then focus it on a film plane (analog) or image sensor (digital). Camera lenses work similarly to the human eye and allow us to control the amount of light entering the camera.  Furthermore, they can be interchangeable or fixed to a camera’s body, depending on its make.

Also read: How to clean a camera lens without a cleaning kit

Here are a few basics and design features that every cameraperson ought to know about camera lenses:

Type of Lens

To answer questions like “what is a prime lens?” or “what is a zoom lens?” we need to treat lens types. Even though there are various categories of camera lenses, they all fall under these two types.

  • Zoom lens: A zoom lens (1) is a lens that has more than one focal length, allowing the user to switch between variables by zooming in and out.
  • Prime lens: On the other hand, a prime lens does not support magnifying or reduction like its zoom counterpart. It is a lens with a set focal length; however, focal distance can still be adjusted by the focal ring.


A lens aperture describes the opening through which light passes before being processed by individual lens elements. They are generally measured in f-stops (estimate), with t-stops (exact) reserved for professional videographers.

An f-number indicates the extent to which a lens diaphragm is open, with higher numbers equating lower openings. For example, the f/1.2 aperture is larger than f/32.

Focal length

The question “what is a camera lens?” cannot be fully answered without discussing focal length. A focal length is the distance between a camera’s sensor and the point at which light converges in a lens (2).

The focal length determines the angle and field of view in a lens. High focal lengths are far and narrow, while low focal lengths are short and wide. And they are usually measured in millimeters. For example 200mm (telephoto), 50mm (standard), 15mm (wide-angle), etc.

Lens Mount

To some users, the lens mount is an essential part of their lens. It is the first step in ensuring compatibility with the camera body. The lens mount comes in various forms, but the electronic adapters are getting increasingly popular in modern cameras. 

It is also important to note that not all cameras allow lens interchanging, as some come with fixed lenses.

Lens Accessories

What is a camera lens hood for? What function does a filter perform? These questions require answers. A lens hood protects the front element of a lens from harsh light, and a lens filter is used to enhance color and reduce light intensity.

The accessories minimize problems like ghosting and flare while creating a more accurate picture.

Seeing questions like “what is a fixed lens camera?” brings two answers to mind. It means either a prime lens with a fixed focal length or a camera that does not support interchangeable lenses.

Also read: How to Choose a Camera Lens

F. A. Q

A maximum constant aperture means that the diaphragm opening is stable at its widest, while a variable maximum aperture indicates that the aperture range is not specific. A variable aperture usually plays at the extreme end of a zoom lens, where lighting might pose a problem.

An anamorphic lens is designed with extra glass elements that allow users to capture a wider angle of view. It achieves this feat by squeezing the image more horizontally than regular sensors would allow.


To fully enjoy a camera, answering the question “what is a camera lens?” and knowing everything about it is the first step as it plays a vital part in videography and the overall outcome of our shots. 

Did we do justice to the topic, or do you still have questions that require answers? Or maybe you just want to add some extra info? Then, why don’t you reach out to us through the comments and leave a note


  1. Haje J. K. (Dec. 11, 2017). Everything you need to know about camera lenses. Retrieved from
  2. Lannom S. C. (Jan. 10, 2021). Camera Lenses Explained: What’s Inside & How Do They Work? Retrieved from