CCTV Buying Guide: What to Know Before Choosing an IP Camera (Housing, Lens, IP66/IP67)
Before buying a CCTV / IP camera, be clear about what you need. Housing, resolution, lens size and weather rating all affect the image you get and your budget. This guide summarizes the essentials, based on our distributor's camera selection guide.
1. Questions to answer before choosing a camera
Question | Options |
Which system? | IP camera / Analog |
Which housing? | Dome, Bullet, Mini Dome, Mini Bullet, Box, Cube, Fisheye, Speed Dome PTZ, Mini PTZ |
What resolution? | 1MP, 2MP, 3MP, 4MP, 5MP, 8MP (4K) |
Lens size? | 2.8mm, 3.6mm, 4mm, 6mm, 8mm, Fisheye, Vari-focal |
Indoor or outdoor? | Indoor / Outdoor (IP66 or higher) |
Wireless or wired? | Wireless (Wi-Fi) / Wired (LAN, PoE) |
How will it move? | Fixed, Pan-Tilt, PTZ (pan + tilt + zoom) |
How many cameras on the recorder? | 4CH, 8CH, 16CH, 32CH, 64CH |
How many hard drives? | 1, 2, 4, 8, 16 SATA |
Built-in PoE on the NVR? | 4 / 8 / 16 ports, or no PoE (use a separate PoE switch) |
Note: NVRs with a built-in PoE switch go up to 16 ports. For more cameras, add a separate PoE switch.
2. Which housing fits where
Bullet – visible and deterrent; ideal outdoors, on fences and in car parks
Dome / Turret – discreet and neat; ideal indoors in shops and offices (IK10 models resist impact)
PT / PTZ / Speed Dome – pans, tilts and (PTZ) zooms; for large yards and warehouses
Fisheye – 180°–360° view; one camera covers a whole room
Wi-Fi camera – no LAN cabling; good for homes and small shops, but depends on Wi-Fi quality
3. Lens size and field of view
A smaller mm value gives a wider view but less detail at distance; a larger value is narrower but sees farther (approximate angles, depending on each model's sensor).
Lens | Horizontal view (approx.) | Best for |
2.8mm | 100°–110° | Rooms, shop fronts, wide areas at short range |
3.6mm / 4mm | 80°–90° | Corridors, house fronts, medium range |
6mm | 50°–55° | Entrances, longer range |
8mm | 40°–45° | Roads and gates where you need detail far away |
Vari-focal (e.g. 2.7–13.5mm) | Adjustable | Sites where the distance is unknown; tune it on install |
4. IP and IK ratings
The first IP digit is dust protection, the second is water protection.
IP66 – fully dust-tight and protected against powerful water jets; suitable outdoors
IP67 – fully dust-tight and protected against temporary immersion (about 1 m for 30 minutes)
IK10 – high impact resistance (about 20 joules) for spots at risk of vandalism
5. Features worth knowing
Resolution (MP) – 2MP = Full HD, 4MP = 2K, 8MP = 4K. Higher means more detail when zooming, but uses more storage
Sensor size – e.g. 1/2.8" or 1/1.8". A larger sensor gathers more light for clearer night images
Lux – the lower the value, the better it sees in the dark (e.g. 0.005 lux)
IR / Smart Hybrid Light / ColorVu / Full-color – IR gives black-and-white night images; LED or white light gives color at night
WDR (Wide Dynamic Range) – handles backlight such as glass doors; 120dB WDR is better than digital WDR
H.265+ – strong video compression that saves storage and bandwidth
PoE – power and data over one LAN cable; use with a PoE NVR or PoE switch
AI / smart functions – human/vehicle detection (SMD), face capture, people counting, license plate reading; fewer false alarms
Memory card – some models take a microSD card (e.g. up to 256GB / 512GB) and can record without an NVR
6. Reading camera model names
Hikvision DS-2CD… – IP camera. The next digit is the series (1 = value, 2 = mainstream, 3 = pro); G2 / G3 are newer generations. Suffixes: I = IR, U = built-in mic, Z = motorized zoom, S = audio/alarm I/O, W = Wi-Fi
Dahua DH-IPC-… – HFW = bullet, HDW = eyeball/turret, HDBW = vandal-proof dome. The first digit after the housing code is the series (1 / 2 / 3 / 5); higher means more features
The number in brackets or at the end, e.g. (2.8mm) / -28 / -36, is the lens size
Shop CCTV at DC Computer Network
Browse Dahua and Hikvision IP cameras, NVRs and PoE switches in our CCTV category, or send us your site details for a free design and quotation.


