When you buy a camera that can change lenses, you're actually limiting your choices when it comes to choosing lenses. For the most part, Canon cameras work with Canon lenses, Nikon lenses with Nikon cameras, Sony lenses work with Sony….you get the idea.

If you're willing to put an adapter in between a lens and camera, however, you can change things up. It's not a new concept—in the old days, it was easy enough to put medium format lenses on 35mm SLRs—but the move toward mirrorless cameras has made things even easier.

The reason is one of physics and optical design. Lenses are made so they can focus on far objects, as long as they are the proper distance away from your camera's image sensor. Mirrorless cameras have a very short space between the lens mount and sensor, making it a relatively simple matter to engineer adapters to support lenses from other systems—the most basic adapters are light-proof tubes with the proper mounts on both sides.

This means that if you use a mirrorless model you can move beyond lenses that are purpose-built for your camera if you want to. There are first-party options, most with some degree of autofocus support, as well as a number of third-party choices.

Today's mirrorless cameras include models with sensor sizes and prices running the gamut. Electronic viewfinder technology is mature, to the point where you'll have an easier time focusing manually using an EVF than an old-school SLR pentaprism. Digital tools, including peaking highlights and frame magnification, eliminate guesswork.

First-Party Lens Adapters

Camera makers that have moved, or are in the process of moving, from SLRs to mirrorless systems tend to offer adapters to make the process easier for existing customers.

Canon offers adapters for both of its mirrorless systems (the APS-C EOS M and full-frame EOS R) so you can use its SLR lenses with full autofocus and aperture control. These adapters also work with compatible third-party glass from brands like Sigma and Tamron.

Nikon has its Z system, with one mount for both full-frame and APS-C camera models. Its FTZ adapter brings full support for autofocus and aperture control to most lenses that are compatible with its F-mount SLRs. The adapter doesn't support autofocus for very old lenses that require a screw to drive focusing elements, but is fine with modern lenses with internal focus motors.

Sony's owners also have access to adapters, the LA-EA4 with its own, dedicated autofocus system, and the LA-EA3, which leverages your camera's autofocus sensor. They're useful tools for system owners with a stash of A-mount SLR lenses from Minolta and Sony.

Third-Party Lens Adapters With Autofocus

Adapters are also from sources outside of the big three. While many are simple mechanical spacers, useful only for fully manual lenses, others go further and add autofocus support.

Sigma, which also makes its own cameras and lenses, sells the MC-11 and MC-21, so you can use Canon or Sigma SLR lenses with other systems. The MC-11 works with Sony cameras while the MC-21 works with L-mount models from Leica, Panasonic, and Sigma.

Canon's lenses have proven to be the most popular targets for other third-party adapter makers. Brands like Fotodiox and Metabones offer up autofocus adapters for other systems, including Fujifilm X and Micro Four Thirds.

It's harder to move Nikon lenses to other systems. Fotodiox sells one that works pretty well with Nikkor G lenses and Sony cameras, but it will damage your camera if used with one specific lens, the Micro-Nikkor 105mm f/2.8G, due to an electrical issue. I've used it with other lenses without issue.

There is a unique, cross-mirrorless solution for Nikon Z camera owners. Techart sells an ultra-slim mount adapter that works with Sony E mirrorless lenses. It's not the only innovation from the company. Techart also makes an adapter that adds autofocus support to fully manual lenses.

While you can expect mostly uncompromised autofocus performance when adapting within a brand, it's not the case when mixing things up. The Sigma MC-11 and the Fotodiox Fusion adapter series, in general, do a very good job when using your camera in its basic AF-S mode, but can struggle when enabling continuous autofocus and subject tracking.

Very specific compatibility issues are a concern, though. There are so many lens, camera, and adapter combinations, it's really impossible to test every variation. The axiom that you get what you pay for is also at play—it's worth it to spend a little bit more to get a Fotodiox, Metabones, or Sigma adapter.

Manual Focus and Specialty Lens Adapters

If you're willing to give up autofocus support, the price of lens adapters drops steeply. Generic options are often as little as $15, and serve their purpose well. If you're working with a vintage lens with mechanical manual focus support and its own aperture control ring, they'll suit the needs of many photographers.

But there are reasons to spend a bit more. If you want to adapt an SLR lens that doesn't have manual aperture control, you can get an adapter with its own aperture control.

You can also get an adapter with a built-in neutral density filter. This type of filter cuts the amount of light coming into your camera, useful to keep shutter speeds reasonable for video and for still photographers making long exposure images.

For close-up work, adapters with helicoid extension allow you to keep the lens spaced properly for infinity focus most of the time, and move it farther away from the image sensor with a twist of a control ring for close-up work—think of it as a variable-length extension tube for macro work.

There are other specialty adapters, too. Speed Boosters are popular for APS-C and Micro Four Thirds system owners; they feature an optical element that reduces the size of the lens' image circle, giving it an angle of view close to what you get from a full-frame camera. The optical element definitely has an effect on image quality, but you may find the trade-off worthwhile.

Tilt-shift adapters use the additional space between the lens and sensor to add movements to your SLR lens, just like you get with a dedicated Tilt-Shift optic. They allow you to adjust the angle at which light hits the sensor, or to correct perspective.

How to Find the Right Lens Adapter

If you know what kind of lenses you're trying to adapt, finding the right one is pretty simple. But what if you don't? It's easy enough to stumble upon old camera gear at thrift stores and garage sales, and it's often passed down through family trees.

Lenses typically have some sort of branding, and if it has a camera company name or a mount name, it shouldn't take too much searching to get the right adapter. Identifying marks are usually printed around the front glass. If you also have the camera that goes with your old lens, its brand and model number can tell you exactly what adapter to get—you might just have to do a little research to put the pieces together.

Online resources like Camera-Wiki and 35mmc are good starting points to find out exactly what type of old lens you've got. You'll need to look beyond just the brand name to determine the lens mount. Focal length, aperture, the serial number, and the look and feel of the lens itself are also clues.

Assuming the old glass you have was at all popular, you should be able to locate an adapter easily. Adapters turn up willy-nilly in retail searches at big online outlets, but if you go to a photo specialty retailer, you can often drill down based on lens and camera mounts to quickly narrow the results.

Once you've found the right adapter, head over to our story on 10 beyond-basic digital photography tips to learn how to get the best shots.

• How to Use Your Canon DSLR as a Webcam
• 10 Easy Tips and Tricks for Better Smartphone Photos
• How to Photograph a Total Lunar Eclipse
• How to Change Your Background in Microsoft Teams
• More in Cameras

• Fujifilm X-T4
• Nikon Coolpix P950
• Olympus M.Zuiko Digital ED 12-45mm F4 Pro
• Olympus OM-D E-M1 Mark III
• Rokinon 18mm F2.8 AF Sony E

• The Best Digital Cameras for 2020
• The Best DSLR and Mirrorless Cameras for 2020
• The Best Bridge Cameras for 2020
• The Best Full-Frame Cameras for 2020
• The Best Point-and-Shoot Cameras for 2020