Review: Eufy Eufycam S4

We tested and were very impressed by the EufyCam S3 Pro just over a year ago, giving it a full 9 out of 10. Now Eufy has released the successor, EufyCam S4, which takes the concept several steps further. Three lenses in a single camera, motorized PTZ that follows movements automatically, a more powerful solar panel, and all without any subscription requirements.

It sounds almost too good to be true, so the question is whether it really delivers on its promises. We’re going to find out!

Design and first impressions

As soon as we unbox the eufyCam S4, we are struck by its size. It is significantly larger and heavier than the S3 Pro, weighing a full 745 grams for the camera alone. Add the 308-gram solar panel, and it becomes a substantial piece of equipment to mount on a wall. It is large, heavy, and feels incredibly robust. This is not a discreet little camera you hide under the eaves, but a camera that truly stands out.

But on the other hand, it’s meant to be seen. A large, visible security camera has a deterrent effect in itself. The build quality is excellent; it feels solid and weather-resistant. The included mount is stable with security screws, and the battery is easy to remove via USB-C for charging.

The camera comes with a separate 5.5 W solar panel that can be mounted on top of the camera. It’s clever that the panel is detachable. If the camera is in the shade, you can use a cable to move the panel to a sunnier spot. Eufy claims that one hour of direct sunlight is enough to power the camera for an entire day.

The camera also features a replaceable 10,000 mAh battery, which is unusual in this class and a big plus for longevity.

Installation

Installation takes place via the Eufy Security app, and unlike some of its siblings in the S-series, the S4 works perfectly well on its own. This means you don’t need a HomeBase 3 to get started, which is a major advantage for those who just want to buy a standalone camera. However, if you already have a HomeBase 3 (S380), you just need to press the sync button to include it in the ecosystem and gain access to extra storage and more advanced AI.

During installation, we had quite a few problems getting the camera to detect the built-in storage, and we had to restart several times and upgrade the firmware before it worked. Hopefully, this was just a temporary glitch, but it was very annoying in an otherwise very smooth installation process.

You are guided step by step, and when it works, it only takes a few minutes for the camera to be up and running. The included mount is stable, which is necessary given the weight. However, keep the placement in mind, as the camera needs a clear line of sight for both the fixed lens and the moving part.

Tri-Cam technology and features

What makes the S4 unique is that it combines three lenses into one device. At the top is a fixed 4K camera with a 130-degree wide angle that keeps a constant eye on the big picture. Below it sits a motorized PTZ module with two 2K lenses that can pan and tilt 360 degrees.

In practice, it works by having the fixed 4K camera act as a scout. When it detects movement, it sends the coordinates to the PTZ section, which quickly turns, zooms in, and follows the object. Eufy calls this “AI Tracking 2.0.” It works surprisingly well. The transition when the PTZ camera takes over is mostly seamless, and thanks to the fixed lens, you avoid the problem of the camera looking the wrong way when something happens at the other end of the garden.

Image quality

Image quality during the day is very good (the video above is compressed and looks better in the app). The fixed 4K lens provides a sharp and detailed image. The PTZ lenses, with their 3x optical zoom and up to 8x hybrid zoom, make it possible to see facial details even at longer distances.

However, there is one technical detail that feels a bit strange. Even though the main sensor is 4K, the video streams are combined into a file where the fixed image is at the top and the zoomed-in image is at the bottom. This means the actual resolution in the exported clip is not “true” 4K. If you want pure 4K, you have to switch to single-camera mode, but then you lose the whole point of the dual-camera setup.

Night mode is good. Color night vision with the help of the built-in spotlights provides a clear and useful image even in the dark. It’s not quite on par with the S3 Pro’s MaxColor Vision, which we thought was fantastic, and it’s one of the things we miss most in the S4. With the S3 Pro, we could see colors almost as clearly as during the day, even in near-total darkness, and that feature is missing here. It’s not bad—it’s still good—but it’s a noticeable downgrade for anyone coming from the S3 Pro.

Detection and AI

Just like the S3 Pro, the S4 uses a combination of radar and PIR sensors for motion detection, and it works well to distinguish between people, vehicles, and other movement. False alarms are few, provided you take the time to configure activity zones and the types of events you want to be notified about. Configuring activity zones and privacy zones for both cameras is also quite fiddly, and you need to set zones separately for the bullet and PTZ parts. It works, but it requires patience.

Notifications arrive quickly, about four to five seconds from the moment motion is detected until you have a notification on your phone.

Connecting the camera to HomeBase S380 (which is not included in the single-camera package) gives you access to Eufy’s BionicMind AI with local facial recognition and cross-camera tracking.

Facial recognition works okay but isn’t flawless. It sometimes misses or has trouble identifying people wearing hats and/or scarves, which is not uncommon during a Swedish winter.

App and usage

Eufy’s app is feature-rich but can sometimes feel a bit cluttered with all the settings. The Swedish translation, which we complained about quite a bit in the S3 Pro review, has improved significantly, but there are still some ambiguous references and odd word choices. It’s livable, but for a product in this price range, it should be perfect.

However, the biggest problem with the app is that it takes too long to access the live view. Sometimes it takes five seconds, sometimes ten, and sometimes even longer before we could see what the camera sees. This is too slow for a flagship model. When you get a notification that something is happening, you want to be able to see it immediately, not sit and wait.

Storage

Just like with the S3 Pro, the major advantage is that no subscription is required. All storage is local. The camera has 32 GB built-in (expandable with microSD).

Conclusion

The EufyCam S4 is an impressive and ambitious product. The concept of three lenses in one camera, where a fixed 4K camera always provides an overview while a motorized PTZ camera follows and zooms in on movements, works very well in practice. The tracking is excellent, the image quality is high, and avoiding subscriptions with local storage is a major plus.

But there are things that drag it down. The slow live view in the app is frustrating. The fact that it doesn’t save in true 4K in dual mode is a shame. The lack of MaxColor Night Vision found in the S3 Pro is noticeable. And the camera is large and expensive.

At a price of 3,990 SEK for a single camera, it’s an investment. However, the fact that it works standalone without a subscription makes it an easier entry point than if you had to buy the base station immediately. It’s a lot of money, but if you want a really good camera that can cover a large area, the eufyCam S4 is hard to beat. But if you don’t need motion tracking and zoom, the EufyCam S3 Pro might be a better choice.

Eufy sent review units for this test. Senders of material have no editorial influence on our tests; we always write independently with our readers and consumers in focus.