Buying guidance for Australian homes and small businesses. Product listings and manufacturer specifications checked in November 2026. Confirm the supplied model, lens and HDD option before ordering.
For the same camera family, a 2.8 mm lens generally covers more width; a 4 mm lens generally concentrates the view on a smaller area. Choose the view that gives useful detail at your entry, driveway, counter or gate. A motorised varifocal lens is worth comparing when the exact framing needs adjustment after mounting.
The number on the lens is not a universal viewing angle or identification distance. Sensor size and camera design also matter. This guide uses Hikvision and Dahua examples and links to the actual store listings. Compare cameras · Read the FAQs.
2.8 mm, 4 mm and varifocal: the buying difference
| Lens type | What to compare |
|---|---|
| 2.8 mm fixed |
Useful starting point: Broad nearby entry or room overview Trade-off to check: Distant subjects occupy less of the image |
| 4 mm fixed |
Useful starting point: A more concentrated view in the same family Trade-off to check: Less width; nearby movement can leave the frame |
| Motorised varifocal |
Useful starting point: Adjustable framing for a defined target area Trade-off to check: Choose the final view and test it at both near and far points |
Some Dahua families offer a 3.6 mm option rather than 4 mm. Do not treat them as interchangeable labels. Compare the manufacturer’s horizontal field of view for the exact model and lens. Axis’s lens guide explains why both focal length and sensor size determine the view.
A wider view and a detail view solve different tasks
A wide driveway overview can show where someone walked and which vehicle they approached. A separate, tighter view at the gate can give more image area to the person passing through it. The narrower view sacrifices coverage elsewhere. Increasing megapixels does not remove that trade-off.
The diagram shows framing choices, not footage or a measured performance comparison. A wall, parked vehicle or tall shelf still blocks the view regardless of focal length. Moving the camera or adding another viewpoint may solve the problem better than zooming.
Choose by the distance to the task
Porch or close front door
A wider fixed lens can help cover a nearby approach and doorstep, but check how large a face is at the important point. A high mount and steep angle can hide faces. Test someone approaching, pausing at the door and turning away.
Long driveway or side gate
If the useful target is a defined area farther away, compare a narrower fixed view or varifocal lens. Keep enough width for the approach you need. Check the closest point too; tightening the far-gate view can exclude a person near the house.
Side passage or shop aisle
Choose framing that uses the image on the passage rather than mostly walls or shelving. Check any supported corridor/rotation mode as a separate feature and confirm recorder display support. A longer lens cannot see behind an aisle end or through a projecting wall.
Wide frontage
A 2.8 mm camera is not automatically a 180-degree camera. Compare the stated field of view. For a broad open frontage, see our panoramic camera versus two cameras guide and keep a dedicated detail view where needed.
Fixed and motorised cameras to compare
These examples are grouped by framing task, not by a claim that equal focal lengths give equal performance across brands. Product pages show current prices and supplied options.
Hikvision DS-2CD2367G3-LIS2UY/SL — 6MP ColorVu 3.0
A candidate for an entry or rear access point needing Hybrid Light, two-way audio and configurable warnings. The listed default lens is 2.8 mm; confirm any alternative before ordering. Requires suitable PoE+ and total power capacity.
View this product, current price and supplied options · Manufacturer specifications
Dahua DH-IPC-HDW3667EM-S-IL-ANZ — 6MP Smart Dual Light
A candidate for fixed-view entry or general monitoring with IR and event-triggered warm illumination. It includes a microphone, but not a talk-back speaker. Confirm the supplied focal length; manufacturer lens options are not proof of store stock.
View this product, current price and supplied options · Manufacturer specifications
Hikvision DS-2CD2667G2HT-LIZS — 2.8–12 mm motorised bullet
A 6MP varifocal option for framing a driveway, gate or defined entry area after mounting. The checked datasheet specifies horizontal views from 112.3° to 41.2° across the lens range. Check its PoE+ requirements.
View this product, current price and supplied options · Manufacturer specifications
Dahua DH-IPC-HDW3667T-ZS-IL-ANZ — 2.7–13.5 mm motorised turret
A 6MP Smart Dual Light varifocal option for setting an aisle, gate or entry view. Its focal-length range differs from the Hikvision bullet. Check the required search and event functions with your recorder; a motorised lens is not a pan-and-tilt mechanism.
View this product, current price and supplied options · Manufacturer specifications
What motorised varifocal does — and does not do
A motorised varifocal lens lets you adjust the optical framing and focus using supported controls. For example, the checked Hikvision 2.8–12 mm model specifies a horizontal view from 112.3° at the wide end to 41.2° at the tele end. Those figures belong to that model; they are not universal angles for all 2.8 mm or 12 mm cameras.
Set a view that captures the task, then verify focus and recorded detail in daylight and at night. This fixed bullet or turret body does not mechanically turn like a PTZ simply because its lens is motorised. Digital zoom in playback only enlarges the pixels already recorded.
Do not choose a lens using an illumination-distance claim
A quoted IR or white-light range describes an illuminator specification under stated conditions. It is not a promise that a face or number plate will be usable at that distance. Read any DORI figures as planning information tied to assumptions, then test the real task.
Night-time movement also needs appropriate light and exposure. A bright empty image can still produce blurred walking subjects. Use the night-vision buying guide alongside the lens decision.
Five checks before ordering
- Mark the camera mounting point and the nearest and farthest important targets.
- Measure the width you want in view at the target distance.
- Compare the exact horizontal field of view, not only the focal-length label.
- Confirm the store’s supplied lens variant, power requirements and recorder support.
- Test recorded moving subjects by day and night before treating the view as finished.
Browse Hikvision security cameras and Dahua security cameras. For a shop layout, use our small-shop CCTV planning guide to decide which views need overview or closer detail.
Frequently asked questions
Is a 2.8 mm or 4 mm security camera better?
For the same camera family and sensor, 2.8 mm generally gives a wider view and 4 mm a narrower view. Choose by target distance and the detail needed, then check the exact horizontal field of view. Neither focal length is universally better.
How far can a 4 mm camera see?
There is no single useful distance for every 4 mm camera. Resolution, sensor, lighting, angle, subject motion and the task all matter. Seeing that someone is present is different from capturing a useful face image.
Is Dahua 3.6 mm the same as Hikvision 4 mm?
No. They are different focal lengths, and field of view also depends on the sensor and camera design. Compare the actual horizontal field-of-view figures and required framing rather than treating the labels as identical.
Can I zoom a fixed 2.8 mm camera to make it a 4 mm camera?
Digital zoom crops and enlarges the captured image; it does not change the optical focal length or recover detail that was never recorded. A motorised varifocal lens changes optical framing within its specified range.
Does a motorised varifocal camera follow people?
Not simply because its lens is motorised. Lens adjustment changes zoom and focus; it does not add mechanical pan or tilt. Check any tracking function separately on the exact model.
Should a narrow side passage always use a longer lens?
No. A longer lens can waste less image area on walls when the target is farther away, but can miss someone close to the camera or near a doorway. Check both the nearest and farthest important positions.
Can a 4 mm camera read number plates at night?
Focal length alone does not establish plate capture. Vehicle speed, distance, angle, exposure, headlights and lighting must be designed for the task. A general overview camera is not automatically a suitable plate camera.
Can I order every featured fixed camera with a 4 mm lens?
No. A manufacturer’s lens options do not establish the available store variants. Check the linked listing and confirm any alternative lens before ordering. The product examples in this guide identify the supplied/default options where known.