What criteria should be used when selecting a security camera?
When selecting a camera system, the first question is not "how many megapixels"; the first question is: what do you want to do with this camera? Seeing a vehicle pass, monitoring what a person is doing, identifying someone you know, and identifying the identity of someone you don't know are four separate requirements, and each requires different resolution. Without determining this, the system purchased is either more expensive than necessary or produces the result "there is image but nothing is clear" at the time of the incident.
Selection guide and FAQ
First, determine the purpose: pixels/meter criterion
The IEC 62676-4:2014 standard (EN 62676-4:2015 in Europe) defines camera performance by the number of pixels per metre on the target plane. This is the measure we use when designing a system — not the megapixel figure on the camera label, but the pixel density achieved at the distance where the target is. The levels in the table belong to that edition; IEC 62676-4:2025, published on 9 October 2025, introduced a new seven-level scale according to manufacturers’ technical notes (secondary source; the standard text is paid) — the comparison and a calculator are in the lens and megapixel guide.
| Purpose | Required density | What it achieves |
|---|---|---|
| Detection (is something there?) | 25 pixels/metre | You understand that there is human/vehicle movement in the area; who it is cannot be determined |
| Observation (what is happening?) | 62.5 pixels/metre | What the person is doing, which direction they are going is monitored; clothing color is distinguished |
| Recognition (do I know this person?) | 125 pixels/metre | You can tell whether the person in the image is someone you have seen before |
| Identification (who is this person?) | 250 pixels/metre | Enough facial detail to establish the identity of someone you do not know |
Analog (HD-TVI/AHD/CVI) or IP?
This is the most frequently asked question and there is no single correct answer — what matters is your existing cabling infrastructure.
| Topic | Analog HD (coaxial) | IP (network cable) |
|---|---|---|
| Cable | Existing coaxial is preserved; separate power is run | Cat6 single cable; power also supplied from the same cable via PoE |
| Distance (single cable) | Varies by manufacturer, cable and resolution (e.g. a DVR datasheet in the catalogue gives 1,200 m at 720p and 800 m at 1080p for HD-TVI; the higher the resolution, the shorter) | 100 m (standard Ethernet); beyond that, extended with a switch, fibre or a long-distance PoE mode that lowers the speed |
| Resolution | In practice 2–8 MP; limited options at the upper end | Wide range from 2 MP to 4K and beyond |
| Image analysis | On the recording device, limited | On the camera: line crossing, area intrusion, human/vehicle discrimination, license plate |
| Digital zoom | Poor — insufficient pixels | Strong; field can be enlarged after recording |
| Installation cost | Low in existing facility (cabling not renewed) | Low in new facility; cabling cost applies in older facility |
| Does it require network information | No — plug and play | Yes: IP plan, switch capacity, PoE budget |
| Disadvantage | Low analysis and resolution ceiling | Video freezes/drops if network setup is incorrect |
Camera types and where they are used
| Type | Where suitable | Caution points |
|---|---|---|
| Dome | Indoor, ceiling; store, office, corridor | Direction of view is not apparent from outside; dome glass IR reflection can bounce light inward (image becomes blurry when soiled) |
| Turret (eyeball) | Indoor and outdoor; alternative to dome | With no dome glass, IR light cannot reflect back off the glass; its viewing direction is easier to read than a dome’s |
| Bullet (cylinder) | Outdoor, facade, parking lot, long distance | Visible, high deterrent effect; however, direction is readable from outside and prone to snow/dust accumulation |
| PTZ (pan/zoom) | Wide open area, port, field, stadium | Meaningful only if there is a dedicated operator monitoring or automatic tracking setup; will miss events when viewing another direction. Fixed camera is added alongside |
| Fisheye / 360° | Wide indoor field of view from a single point | Covers the entire area but detail is weak; not suitable for identification |
| Thermal | Perimeter security, total darkness, wide open areas | Sees temperature difference: does not require light but does not READ faces and plates. It is for detection, not diagnosis |
| License plate recognition (ANPR) | Vehicle entry-exit | It is a separate discipline; angle, speed, and illumination are critical. Detailed explanation is provided in our License Plate Recognition category |
Six key details that make the most difference in the field
- Night vision comes from the camera’s own infrared (IR) light; the IR range on the label (e.g. 50 m) is given under the manufacturer’s own measurement conditions. Walls, trees or rain shorten the real range. Where there is some light, low-light (starlight) sensors that give colour night images are more useful — clothing colour is lost in a black-and-white IR image.
- Backlighting (entrance door, glass facade, storefront) turns a person into a silhouette in a camera without WDR capability. WDR is not a negotiable feature in entrance cameras.
- Outdoors, IP66/IP67 (water-dust) is required; in impact-prone areas, IK08–IK10 (vandal) rating is sought. For cold storage and open field applications, operating temperature range must be verified.
- Recording duration depends more on the camera's bit rate than on disk size. H.265 compression takes roughly half the space compared to H.264; this means twice the duration on the same disk. We calculate recording duration during survey along with the number of cameras and resolution.
- The recorder and its disks matter as much as the cameras: a desktop disk not designed for 24/7 writing carries a higher risk of early failure, so continuous recording uses surveillance disks. The recorder itself should not be placed where it can be broken; it belongs in a locked cabinet or a separate room.
- A system without an uninterruptible power supply stops recording the moment the power is cut; someone who cuts the power and gets in is not recorded. A UPS for the recorder, switch, modem and, in analogue systems, the power unit feeding the cameras goes into the budget from the start.
Because video recordings make a person identifiable, they are personal data under Law No. 6698. In practice three things are needed: (1) a visible information sign at the entrance to the area the camera watches; (2) a written definition of who may access the recordings (an authorisation matrix) and prevention of unauthorised access; (3) recordings kept for a period limited to the purpose and then deleted. Cameras should also not see the neighbouring plot, residential windows or the public road more than necessary. According to the Authority’s announcements of 8 June 2026, cameras should not be placed in private areas at work such as toilets, changing rooms, prayer rooms and rest areas; in apartment buildings they should not be placed in stairwells or in front of flat doors in a way that shows the inside of the flat when the door opens. We set camera angles within this framework during installation; details are in our KVKK and cameras guide.
Frequently asked questions
Do I need to replace my cables when upgrading from my existing analog cameras to IP?
Not necessarily. There are converters (EoC) that carry IP signal over existing coaxial cable; they can be used to avoid cabling costs. However, in a new installation or if cabling is already being renewed, setting up IP directly with Cat6 and PoE is both cheaper and more capable. For gradual migration, hybrid recording devices accept both analog and IP cameras together.
How many megapixels should my camera have?
Megapixels alone is not an answer. What is decisive is how many pixels per meter you obtain at the distance where the target is located; this depends on the lens angle. A wide-angle 4K camera may provide less recognition capability than a narrow-angle 2 MP camera. The correct approach is: first determine the purpose (detection/observation/recognition/identification) and the width to be monitored, then select the lens and resolution accordingly.
How long should recordings be retained?
There is no single period that applies to everyone; the KVKK principle is that a recording is kept for the period set in the relevant legislation or for as long as the purpose requires (Art. 4/2-d). For some businesses the regulation sets the period: recordings are kept for 90 days at jewellers and paid internet halls, and for at least 30 days in the common areas of shopping centres. Keeping recordings longer than necessary is a KVKK risk, while keeping them too briefly loses the recording when an incident is noticed late. The list by sector and the disk calculation are in the guide on how many days a camera records.
Can I view the cameras from my phone?
Yes, mobile viewing is standard in both analogue and IP systems. What really matters here is security: instead of exposing the device directly to the internet, the manufacturer’s cloud service or a VPN should be used (if the manufacturer’s cloud server is abroad and the footage passes through or is stored on it, in our reading the KVKK Art. 9 rules on transfer abroad come into play), default passwords must be changed and the device firmware kept up to date. Preventing unauthorised access to recordings is also part of the KVKK data security obligation (Art. 12).
Is it worth buying an AI-powered camera?
Models that distinguish between humans and vehicles significantly reduce false alarms caused by leaf movement and shadows — in systems where alarms are actually monitored, this keeps the system usable. Facial recognition, however, is a different matter entirely: biometric data is specially qualified personal data and its installation creates separate legal requirements; we do not recommend it unless specifically requested.
Does a camera system prevent theft?
Visible cameras are a deterrent, but not a barrier on their own. A camera records the incident; an alarm system reports it instantly. Installing both together, with the relevant camera view opening automatically when the alarm is triggered, both reports the incident and puts it on record.