REOLINK E321 (3 MP) - WI-FI IP CAMERA

Mains-powered over USB-C, which is what makes continuous recording possible

The E321 runs from a USB Type-C cable and an ordinary 5 V adapter, so it is a permanently powered fixture rather than a battery device that has to ration its energy. That distinction matters more than the spec sheet suggests: Reolink's battery lines, Go and Argus, wake on an event, capture a short clip and go back to sleep, while the E321 holds a live stream and can write to its memory card around the clock. Indoors that is exactly what you want, because the archive shows not only the moment the detector fired but also the ten minutes before and after it, which is usually where the explanation lives. The trade-off is dependence on the grid: a blackout takes the camera down together with the router, so in a home with frequent outages it makes sense to feed it from the same power bank or UPS that keeps the internet equipment alive. Its draw is tiny, so even a modest power bank buys several hours of uptime with no modifications at all.

355° of pan and 50° of tilt: one mount instead of three cameras

A twin-motor pan-tilt head lets the camera swing 355° horizontally and tip 50° vertically, so a single unit placed in the middle of a room covers almost all of it. You can steer it by hand from the app, store presets — cot, front door, window — and jump between them with one tap. Auto-tracking is included as well: once the analytics identifies a person or a pet, the camera keeps the subject framed for as long as it moves through the covered zone. The limitation of any moving head is worth stating plainly: at any given instant the lens points one way only, so while it follows the cat across the living room, the opposite corner is simply not being recorded. For a spot that must be covered without gaps — a safe, a till, a single doorway — pair the pan-tilt unit with a fixed camera instead of hoping it will swing back in time.

3MP, a 4 mm lens and 15 frames per second: what you actually get

The 1/3" sensor delivers 2304×1296 pixels at 15 frames per second, which is a clear step up from the 2MP cameras that still fill this price bracket, though a step below the 5MP E331. The 4 mm F2.0 lens covers 77° horizontally — moderately narrow for indoor use, but that buys a longer usable distance and far less edge distortion than an ultra-wide optic gives you. In a 4×5 metre room faces stay reliably identifiable out to roughly four or five metres; past that the image degrades into a recognisable shape rather than a recognisable person. Fifteen frames per second is enough for domestic scenes — someone walks in, picks something up, leaves — but fast movement close to the lens can smear in individual frames when you step through the recording. If the point is a small detail at a distance rather than the event itself, either move the camera nearer to the spot that matters or look at the 5MP model.

Night vision: eight IR LEDs, twelve metres, and an honestly monochrome picture

After dark the camera switches on eight infrared LEDs rated for about twelve metres, which covers a bedroom, a nursery or a hallway with room to spare. Infrared light is invisible to the eye, so the camera neither disturbs sleep nor advertises itself — the reason this scheme is standard on indoor models. What you should know before buying is that there is no white spotlight here, so the night image is always black and white and it will not tell you the colour of a jacket or a bag. The second common disappointment is placing the camera behind glass: the IR LEDs light up the pane from the inside and you get a milky haze instead of the yard, so filming outdoors through a window will not work with this model. When colour at night is genuinely the requirement, that job belongs to cameras with hybrid illumination, and those are almost always outdoor units in a higher class.

Person, pet and baby-cry detection all run inside the camera

The analytics runs on the device itself, so the E321 separates a human being and a pet from generic movement and only pushes the categories you have left switched on. Cry detection is implemented separately: the camera reacts to the characteristic sound and alerts the parents, which is why this model is so often bought as a baby monitor that doubles as a security camera. The value of that filtering becomes obvious by contrast — a camera without object classification reports every change of pixels, including the cat landing on a cupboard, headlights sweeping the ceiling and a curtain moving by an open window. The owner of such a camera mutes notifications within a week, and from that moment the system stops working as security at all, which is why human detection matters more in practice than an extra megapixel. Two-way audio rounds out the picture: the built-in microphone and speaker let you answer rather than just listen — soothe a child, call the dog, or let a stranger know he is on camera.

2.4 GHz Wi-Fi only, H.264 encoding and cards up to 512 GB

The camera works exclusively on the 2.4 GHz band — 5 GHz is not supported — and that band trades peak throughput for far better penetration through walls and concrete floors, which in a flat is usually a gain rather than a loss. The downside is congestion: in an apartment block 2.4 GHz is crowded with neighbouring networks, so when the picture starts breaking up the first fix is a cleaner channel on the router, not a new camera. Video is encoded in H.264, which is compatible with absolutely everything but takes noticeably more space than modern H.265 at the same quality, and that has to be part of your storage arithmetic. MicroSD cards up to 512 GB are supported, and on a card that size continuous 3MP recording lasts roughly a week to ten days or a little more, depending on how busy the scene is and on the bitrate you choose. If you need a deeper archive, or one that does not disappear together with a stolen camera, the E321 connects to Reolink NVRs and the Home Hub, leaving the card as a fallback for network dropouts.

Where this camera belongs, and where it has no business being

The natural habitat is a flat, a nursery, an elderly relative's room, a living room with a pet, a small office or the counter of a small shop — anywhere one camera should see the whole space and let you talk through it. The housing is rated for indoor use with an operating range of -10 to +55 °C, which rules out an exposed terrace, an open porch or an unheated garage through a Ukrainian winter. It is equally wrong for gate and number-plate duty: 4 mm and 3MP describe a room, they do not read a plate at distance. Nor should you count on it being discreet — the moving head is visible and audible, so the camera declares its presence rather than hiding it. You get the best result by standing it on a shelf or fixing it to the ceiling near the middle of the room; mounted in a corner, a 355° sweep loses half its value because half of the circle faces a wall.

How it compares with its neighbours in this catalogue

Its closest relative is the Reolink E Series E331 [1594]: identical body, identical pan-tilt head, but a 5MP sensor instead of 3MP, a brighter F1.6 lens, a wider 87.5° field and dual-band Wi-Fi 6. The E321 is the junior model of the line, and paying up for the senior one earns its keep mainly in large rooms, in dim light, or where the 2.4 GHz band around you is already saturated. The Imou Ranger 2 gen 2 [1565] competes in the same pan-tilt niche, but per this catalogue it has no human detection and therefore alerts on any movement at all — if you want meaningful notifications rather than just a recording, that single line decides the comparison. The Ajax IndoorCam [1555] is the pick for households that already run an Ajax hub, since it joins the alarm scenarios, though it is a fixed camera with neither pan nor tracking. And if the camera is meant for outdoors, no E-series model will do: this catalogue offers the wired Reolink P334 [1582] and the battery-powered Argus B340 [1577], which are built for rain and frost.

Tell us the size of the room and what exactly you need to see, and we will suggest the mounting point and whether the 5MP version is worth it in your case.