Next to the camera body, your camera lenses are the second most important part of your camera. Selecting the right lens (or lenses) is essential for getting the shots you want. Selecting a new camera lens requires time and research because you have to consider several factors; desired focal length, lens speed, compatibility with your camera, and budget.
In this article on Camera Lenses Explained, our goal is arm you with information you’ll need to select the best possible lens that meets your needs. At some point in time you may find yourself shopping for a new lens for either practical or creative reasons. The first step is the process is to determine the variables you need to take into account when selecting your new lens.
Criteria for Selecting Camera Lenses
You need to take several factors into consideration when selecting a camera lens;
- Purpose (portraits, landscape, sports, architecture)
- Focal Length
- Speed (1.4, 2.8f, 4.5/f)
- Format (Cropped APS-C or Full-Frame)
- Features (image stabilization, silent autofocus)
Lens Focal Length
The Focal length of a camera lens, usually represented in millimeters or mm, is a description of the lens, but is not a measurement of the actual length of the lens. Focal length is a calculation of the optical distance from the point where light rays converge to form an in-focus image of the subject to the digital sensor in the camera. The focal length of a lens is determined when the lens is focused at infinity.
The focal length basically tells us the angle of view, or how much of a scene will be captured and the magnification (how large elements will be in the image). Longer the focal lengths have a narrower angle of view and higher magnification. Shorter the focal lengths offer a wider angle of view and the lower or smaller the magnification.
Here are five apertures and their most common use;
- 17mm – Extreme Wide Angle (Architectural and landscape photography)
- 21-35mm – Wide Angle – (Landscape photography)
- 35-70mm – Normal Zoom (everyday photography)
- 70-135mm – Telephoto Zoom (Portraits)
- 135-300mm – Telephoto (Wildlife, Sports, and Bird photography)
Camera Lens Types
You need to familiarize yourself with are the various types of lenses available for your camera and the various definitions. Before we go any further, we’re assuming you have, or plan to purchase a digital camera the accommodates removable interchangeable lenses. There are five general categories of camera lenses;
A prime lens has a single focal length. They are smaller and lighter than other lens. The most popular focal length is 50mm, which is supposed to be a close match to the magnification of the human eye. Prime don’t zoom in and out due to their fixed focal length. But they produce sharper high quality images than zoom lenses.
Unlike a prime lens with a fixed focal length, zoom lenses have a variable focal length that can be adjusted. Some of the most popular zoom lens focal length ranges are 24-70mm and 24-85mm. Wide-angle zoom lenses are usually 14-24mm and 16-35mm. Telephoto zoom lenses are typically 70-200mm.
A telephoto lens has a long reach, which allows you to shoot a subject that is far away. A lens is considered telephoto if it has a focal length of at least 60mm. Telephoto lenses come in a number of focal lengths from medium telephoto (70-200mm) to super telephoto (longer than 300mm). These lenses can be either zoom or prime lenses. Telephoto lenses make your subject appear closer to your camera and they help emphasize a blurred background.
Wide Angle Lens
Similar to a Prime lens, a Wide Angle lens has a fixed focal length. These lenses have a short focal length (usually around 35mm) and a wide field of view. Ultra-wide angle lens are about 24mm or wider. Wide-angle lenses allow your camera to capture more of the scene than a normal lens can and are ideal for landscape, real estate, and interior photography
A macro lens is for extremely close focusing distances and are capable of taking highly detailed images of tiny microscopic sized subjects like flowers, insects, products, jewelry, coins, and wildlife. Macro lenses allow you to focus extremely close to your subject so it appears large in the viewfinder and image. Another use for macro lenses is portraits (especially headshots and studio portraits). It is hard to beat the stunning sharpness of a macro lens.
Camera Lens Apertures
Another factor to take into consideration is the aperture. There are several different types of camera lens available for a wide range of uses. Lenses are identified by two primary parameters; the maximum aperture and focal length. Shorter focal length prime lenses have maximum apertures ranging from approximately f/1.2 to f/2.8. Telephoto lenses often have a maximum aperture of f/2.8 to f/5.6.
Costlier high-end zoom lenses maintain the same maximum aperture setting throughout their focal length range, while less expensive zoom lenses use a variable aperture range. For example, a lens with an aperture range of “f/3.5 – f/5.6” will be noted on the actual lens barrel as “1:3.5-5.6”. Lens kits sold with many consumer DSLR and compact system cameras often have a maximum aperture of f/3.5-5.6.
Full-frame vs APS-C Cameras
Yet another critical factor