FAQ: What are Interchangeable Lenses?

Written by Peter Dam
|
Updated on May 30, 2022
interchangeable camera lenses
interchangeable camera lenses
Peter Dam
Adorama ALC

Are you ready to become a more creative photographer by making the step up from simple snapshot cameras to serious photographic tools? If you are, then the answer to the question, “What are interchangeable lenses?” is an important start.

Interchangeable lenses are lenses that can be mounted on a camera and swapped out for other lenses. Unlike fixed lenses, which are built into (mostly compact) cameras, interchangeable lenses provide the user with a wider choice of image-capture capabilities. While there are general-purpose lenses that cover the same range as lenses on built-in cameras, the optical quality is generally better. But the true power of interchangeable lenses is in the specialized lenses that are available.

Are Camera Lenses Universal?

Camera lenses manufacturers create lenses for particular purposes, camera types, and camera models. As a result, you have to choose between lenses with different focal lengths and optical characteristics, mount types, and brands.

For example, for a full-frame camera, you need a full-frame lens. And for macro photography, you need a dedicated macro lens. For a Nikon camera, you need either a lens produced by Nikon or a lens fabricated by a third party, especially for Nikon cameras. However, even the lenses made by a camera manufacturer such as Nikon don’t fit all Nikon camera models.

So, are camera lenses universal? No, they are not.

different types of cameras for photography on the grass
Photo by CHUTTERSNAP on Unsplash

Mounts and Cameras

Before we talk about the kinds of interchangeable lenses available, we need to look at the cameras that accept interchangeable lenses. They fall into several categories:

DSLR

Digital Single-Lens Reflex, or DSLR, cameras (which were preceded in the film era by simple SLRs) are made by Canon, Nikon, Pentax, Olympus, Leica, and Sony. These cameras have a reflex mirror and optical viewfinder that allows you to see the actual image projected by the lens. Each DSLR brand has its own mount. Lenses made for a Nikon, for instance, will not fit on a Canon, and vice versa.

Mirrorless

Mirrorless cameras are the newest and fastest growing category of interchangeable-lens cameras. These cameras look like small DSLRs but instead of a reflex mirror viewing mechanism, they use electronic viewfinders, which are basically very small screens that display images that you view through the built-in viewfinder. Sony, Olympus, Panasonic, Nikon, Canon, and more currently make mirrorless cameras and all companies are developing the technology. The mounts for mirrorless cameras are not compatible with DSLR lenses, although there are some adapters available that allow users to mount DSLR or rangefinder lenses on mirrorless bodies.

Rangefinder

Rangefinder cameras are specialized tools that are favored by documentary photographers and photojournalists. They consist of an optical viewfinder and focusing mechanism that lets you view the scene, not through the lens, but parallel to it. Leica is the only company currently making a digital rangefinder, but there are a handful of other companies (Zeiss and Voigtlander) that make film rangefinder cameras, which are still in demand.

camera mount and lens
Photo by ShareGrid on Unsplash

Different Types of Lens Mounts

To use interchangeable lenses, you have to select a set of lenses that fit your camera’s lens mount. Camera brands use a range of lens mounts, so check the characteristics of your camera before buying lenses. Here are the most popular lens mounts:

  • Full-frame DSLR cameras: EF and RF mounts for Canon, F mount for Nikon, SL for Leica, K mount for Pentax
  • Cropped-sensor DSLR cameras: EF-S mount for Canon, F mount for Nikon, TL for Leica, K mount for Pentax
  • Mirrorless cameras: M mount for Canon, 1 and Z mounts for Nikon, E mount for Sony, X mount for Fujifilm, L mount for Panasonic
  • Micro Four Thirds mount is for Micro 4/3 cameras, which have a 75% smaller sensor than the full-frame sensor. It was introduced by Olympus and Panasonic, but you’ll find it on other camera brands as well.
  • Medium format cameras: S mount for Leica, GFX mount for Fujifilm, Pentax 645 A mount for Pentax
  • Film cameras: M mount for Leica, OM for Olympus

Interchangeable Lenses: Types of Lenses

When choosing an interchangeable lens, you have the option of prime lenses (which are a fixed focal length (35mm, 50mm, 200mm, etc.) or zoom lenses (a typical wide-angle zoom might be an 18-35mm, a mid-range zoom, 28-70mm, and a tele zoom 70-200mm). Let’s look at the advantages and disadvantages of primes vs zooms, plus some more specific types of lenses.

commercial photography lenses canon prime lens
Photo by Milind Ruparel on Unsplash

Prime lenses

Generally, prime lenses are optically better than zooms, and are “faster”. A faster lens means it has a wider maximum aperture, such as f/1.4 or f/1.8, which lets in more light and lets you shoot in low-light situations without a flash or tripod. Prime lenses are smaller and lighter than zoom lenses, which makes them better for unobtrusive shooting. While zoom lenses might be jacks of all trades, primes do what they do very, very well. Different prime lenses are designed as “specialists” in macro, portrait, sports, wildlife or other types of photography. Finally, prime lenses can be less expensive than zooms, although top-line pro primes with the best glass and construction available can cost thousands of dollars.

However, prime lenses don’t zoom, which limits you when composing an image. Many photographers are willing to sacrifice speed and a little bit of optical quality for the flexibility of a zoom.

Photo by Cooper Naitove

Zoom lenses

Zoom lenses give you the flexibility to quickly compose or recompose an image without having to change where you are standing. Low-cost zoom lenses are surprisingly light and some offer a long zoom range; many zoom lenses have built-in shake reduction, which is effective in letting you shoot handheld in subdued light without flash. High-end zoom lenses can produce images with quality that rivals prime lenses, have wider apertures, and are made with higher-quality glass elements. Wedding photographers, photojournalists, sports photographers, and travel photographers may prefer zoom lenses because one lens can do many things well.

However, hose low-end zooms are so light because compromises were made. Apertures are smaller, and get smaller still as you zoom in. A typical kit lens‘s widest aperture is f/3.5 at the widest setting but may be as slow as f/5.6 by the time you reach its longest telephoto length. This is known as a variable-aperture lens. There are zoom lenses with wider apertures that remain constant throughout the zoom range, and while these are more desirable, they’re also bigger, heavier, and more expensive.

Olympus M.ZUIKO DIGITAL ED 150-400MM F4.5 TC1.25X IS PRO LENS
Image via Olympus

Telephoto Lenses

Once you know that camera lenses are interchangeable, you may want to use both telephoto and wide-angle lenses.

Telephoto lenses help you capture sharp photographs of objects further away from the camera. They have a high magnification ratio that makes faraway objects appear closer to the camera. At the same time, they reduce the perceived distance between foreground and background, allowing both of them to impact the viewer. Telephoto lenses also create a shallow depth of field and a beautiful bokeh effect.

The disadvantages of telephoto lenses are the narrow field of view, the long minimum focusing distance, and the increased risk of inducing camera shake blur.

Wide-Angle Lenses

As an interchangeable lens, a wide-angle lens helps you achieve a deep depth of field and have the entire frame in focus. It has a wide field of view that makes it suitable for landscape and cityscape photography. At the same time, wide-angle lenses are less prone to camera shake blur, have a short minimum focusing distance, and are lighter and smaller than telephoto lenses.

However, wide-angle lenses increase the perceived distance between foreground and background and make faraway objects seem smaller than they are. As a result, you may lose the details in the background.

fisheye lens for wide angle architecture photography
Photo by Gabriella Clare Marino on Unsplash

Fisheye Lenses

You should include a fisheye lens in your set of interchangeable lenses if you like ultra-wide photographs with a viewing angle close to 180° or more. There are also circular fisheye lenses that produce a peephole effect and a panoramic perspective. As they capture more than the human eye can see, fisheye lenses create a mesmerizing illusion. They are great tools for cityscape and landscape photography, extreme sports photography, astrophotography, and underwater photographs.

Other advantages include a very deep depth of field and extreme clarity and sharpness.

On the negative side, fisheye lenses distort the perspective by bending objects in the frame. So, for example, you’ll have a curved horizon. Also, because they widen the perspective so much, you can end up with pixelated images with low resolution.

Lensbaby Composer Pro II Lens with Sweet 80 Optic
Lensbaby Composer Pro II Lens with Sweet 80 Optic

Specialized lenses

There are lenses specifically designed for portrait and wedding photography, sports and wildlife, photojournalism, architecture, macro photography and more. Some lenses serve overlapping, specialized purposes, but would not be “general purpose” lenses.

Some lenses, such as Perspective Control (PC) lenses, let you tilt and shift the lens, roughly mimicking the kind of controls over linear distortion that you have with view cameras. These are great for architects who need to have lines of buildings they photograph to appear straight, and not “leaning”, a common problem.

Other lenses, such as the Lensbaby line of optics, allow you to more selectively blur areas of an image, creating dreamlike effects. These lenses have become very popular among pros who want to show a different, creative effect.

Peter Dam is a professional nature photographer who loves to explore everything from the tiny world of macro photography to the vast landscape photography. He shares a wide range of photography tips on his website, including tutorials for advanced photo editors like Affinity Photo and Photoshop, over to image management in both Lightroom and Capture One.