The $299 Megadap EFTZ21 Canon EF to Nikon Z Autofocus Adapter should appeal to Canon SLR photographers eyeing a Nikon Z camera for their next upgrade. It allows you to use your favorite EF glass on Nikon mirrorless bodies with little compromise and saves you from taking a loss on your existing lens investments. The adapter worked well with the handful of lenses we tried and performed almost as swiftly as Canon's first-party EF-EOS R adapter. The integrated control ring and function button largely make up for the lack of weather sealing and continuous focus support in video modes, so the Megadap EFTZ21 is an easy recommendation for enthusiasts. If you are a professional who needs the utmost reliability and speed, however, you should likely just invest in native Nikon Z lenses.

Design: Better Than Basic

There's not much to the EFTZ21, but it goes beyond the basic manual-focus adapters that dominate the market in a couple of ways. First, it supports autofocus, electronic aperture control, and both in-lens and in-body image stabilization. Second, it includes an on-barrel function ring and L-Fn button for enhanced control. The L-Fn button works like the one built into Nikon Z lenses and follows any custom mapping you assign via your camera's menu.

Even with those extras, the Megadap EFTZ21 is a pretty simple device. Physics ultimately dictate its form since camera lenses need to mount at a very specific distance from the sensor to focus properly. Its 1.3-by-2.8-inch (HD) barrel positions EF lenses so they can focus to infinity on Nikon Z cameras and match the diameter of the Z mount for a light-tight seal. The matte black interior reduces the chance of light bouncing around inside the adapter.

The adapter uses a quality, all-metal construction and weighs about 5.6 ounces. Megadap doesn't bill it as dust- or splash-resistant but does include a rubber gasket on the camera mount side. Higher-end Canon lenses have a corresponding gasket at their base, and the lens mount here is pretty tight, so the combination should help keep particulates away from your camera sensor. Even so, without full weather sealing, using the adapter in the rain is not a good idea. For those scenarios, consider a Nikon Z lens instead.

The EFTZ21 is the first EF-to-Z adapter I've tested, but it's not the only one on the market. Alternatives like the $299 Fringer EF-NZ II, $189.95 Fotodiox Pro Fusion, and $249 Techart Canon EF to Nikon Z Adapter are similar in concept but don't have a control ring or L-Fn button.

Performance: Works Well, Despite Warnings

A few scary warnings on the listing page for the EFTZ21 indicate that you need to handle it delicately. Specifically, Megadap says that you should avoid swapping lenses or removing the adapter when the camera is on and warns you not to touch the metal pins and contacts on the adapter itself. There's also an oddly phrased note that cautions against turning "the lens and adapter frequently." I asked a rep from the company to explain what that meant but didn't receive a response. My best interpretation is that you shouldn't unnecessarily fiddle with the adapter and mount or unmount it without good reason.

All these notes are good pieces of advice in general—hot swapping a lens is an easy way to get dust on your camera sensor and dirt can cause issues with data terminals—but I'm not convinced these warning messages are necessary. I didn't feel the need to be overly careful with the adapter in hands-on testing, and my review sample continued to work fine even after a couple of hot swaps.

Megadap also warns that leaving the adapter on your camera when you're not using it might drain the battery. This is something I've encountered with other autofocus adapters—the first version of the Techart Leica M to Sony E adapter sucks batteries dry after a couple of days if you leave it attached, for example. But I left the EFTZ21 on a freshly charged Z 8 for a full week and saw no battery drain at all.

Despite all the warnings, the adapter works seamlessly. I tried it with four Canon EF lenses I have on hand for camera testing: the EF 8-15mm F4L Fisheye, EF 11-24mm F4L USM, EF 35mm F2 IS USM, and EF 400mm F4 DO IS II USM. Each worked just as they would on a Canon SLR or EOS R mirrorless camera, providing electronic aperture control, EXIF data transmission, and proper stabilization. The Z 8's advanced focus features, including animal subject recognition, 3D tracking, and eye detection performed perfectly with Canon EF glass.

The only caveat is focus speed. The wide-angle 8-15mm and 11-24mm lenses focus just as quickly with the adapter and Nikon Z 8 as they do on a Canon camera, while the EF 35mm F2 is just barely slower to focus compared with using it on a Canon EOS R5 via the EF-EOS R adapter. The 400mm F4 takes a step backward here, however, with slower focus shifts than on the R5. Still, the Megadap and Z 8 combo proved to be a bit more speedy than the Sony a7R IV and Sigma MC-11 for the same set of lenses. The 400mm F4 drives focus a little more slowly and suffers from some start and stop motion with the MC-11 and the Sony body, for instance.

The Megadap adapter falters a bit for video recording. When you roll movies with the Z 8, racks from one plane of focus to another are on the slow side compared with native lenses. You must also manually trigger visual focus using the camera's shutter release or AF-ON button, even with continuous focus (AF-C) active. These limitations are fine for static scenes but not for self-recorded vlogs, action shots, or other videos in which you want the camera to keep up with a moving subject.

Overall, the focus performance is quite good with the lenses I tested. It's certainly sufficient for photo hobbyists who are mulling a system switch, though I'd caution against using any cross-system adapter for paid, professional work. If you're photographing a wedding reception or sporting event, for instance, you can't risk any delay in focus speed. And if you care more about video than stills, you're better off sticking with first-party Nikon lenses for your Nikon camera.

Verdict: Ease the Switch from Canon to Nikon

The Megadap EFTZ21 Canon EF to Nikon Z Autofocus Adapter is a useful accessory for a limited audience: photographers with a stash of Canon EF lenses who are considering switching or have already switched to a Nikon Z mirrorless camera. The adapter works seamlessly for photography and performance is quick enough to capture most moving subjects. For video, it's an effective solution for static shots but requires you to manually engage focus for most moving subjects. We're happy enough with its performance and build quality to recommend the adapter to enthusiasts transitioning from Canon to Nikon, though pros who require critical performance or who work outdoors in inclement weather should skip straight to native glass.