How to set up a camera system for a market or shop

Which question will the camera answer?

Before talking about the number of cameras, think about the moment of the incident. Say a customer took a product from a shelf and left without paying. When you look at the recording, you want to see the person’s face at the door and the moment they took the product at the shelf. These two images come from two separate cameras. A single wide-angle camera on the ceiling shows the whole shop but lets you make out neither the face nor the product.

For the register, the question is different. You want to see the money the cashier takes, the change they give, and the drawer. For that, the camera should look from slightly behind and above the register. In the storeroom, goods receiving and door movement are watched: who came in, when they left, whether a box arrived missing.

Write these questions on a sheet of paper and put a dot on a rough sketch of the shop for each question. When you talk with the installation team, this sketch quickly clarifies how many cameras and which lens are needed. Start where losses happen most; if the budget is limited, the door and register come first, then the aisles and storeroom.

Where do the cameras go?

The number differs between a small corner shop and a grocery store with two aisles, but the placement logic is the same. The points below apply to most shops.

• Entrance door: from inside, facing the door, close to face level; daylight coming from outside should stay behind the camera.
• Register: an angle looking at the counter over the cashier’s shoulder; the cash drawer and the POS device in the frame.
• Shelf aisles: a camera looking from one end of the aisle to the other; shelves with expensive products come first.
• Storeroom and back door: the door where goods are received and the box stacking area.
• Exterior: shutter, display window and sidewalk; to see shutter tampering at night.
• Special spots where losses occur, such as the cold cabinet and the cigarette shelf.

Expert note: Do not put a camera behind the display window glass to watch the outside. At night the infrared light hits the glass and the image turns into a white glare. Watch the outside with an outdoor camera.

Resolution and lens: detail at the register, width in the aisle

A camera at the entrance with a 2.8 mm lens sees the door and the area in front of it widely. Because the face of a person walking through the door fills a large part of the frame, it can be recognized. If you put the same camera at the very back of the shop, the face at the door drops to a few pixels.

In a long aisle, a 4 mm or motorized lens brings the person at the end of the aisle closer. At the register, having the camera close to the counter to tell a banknote and a product apart is often more useful than high resolution. Megapixels increases, the recording grows too; so instead of putting the highest resolution at every point, choosing high resolution where detail is needed and medium resolution where a general view is enough gives a more balanced system.

Recorder, disk and retention period

IP cameras send the image to the recorder called an NVR. Let the NVR’s channel count be a few more than your current number of cameras; when the shop grows or a storeroom is added, you will not have to buy a new recorder.

Disk capacity depends on the number of cameras, the resolution, the compression type, and whether recording is continuous or motion-based. In a shop that is closed at night, a disk with motion-detection recording lasts a long time. Decide from the start how many days back you want to go; sometimes you notice an incident days later, while doing a stock count. The disk calculator on our site gives a rough capacity based on the number of cameras and the number of days.

The disk alone does not determine the retention period. For the protection of personal data, you are expected to keep the recording for a period appropriate to its purpose. Setting the period in writing according to your business’s needs is a good start; where you are not sure, consult a lawyer.

Viewing from a phone and user permissions

What shopkeepers expect most from a camera is being able to look from their phone when they are not in the shop. The NVR’s app is installed, the device is connected to the internet, and live video and past recordings are opened from the phone.

Two mistakes are common here. The first is never changing the default password from installation. The second is everyone using the same administrator account. Give your employee live viewing permission only; keep the permission to delete recordings and change settings for yourself. When an employee leaves, disable that user. Also keep the motion notifications in the app on only while the shop is closed; if a notification reaches your phone at every customer entry during the day, after a week nobody looks.

The most common mistakes at installation

In a shop camera system, the problem often comes not from the device but from decisions made on installation day. Most of the mistakes noticed when an incident happens and the recording is checked could have been prevented from the start.

Running the cable through the attic space or a conduit takes a bit more effort on the first day, but cutting a cable that hangs out in the open later is the easiest way to blind a camera. Showing the image of the camera that looks at the register on a monitor facing the customer side is also a deterrent; just make sure the monitor does not show the cashier’s password entry or card details.

• Placing the camera facing out against the door: in daytime backlight the face goes dark.
• Trying to cover the whole shop with a single wide-angle camera.
• Putting the NVR under the register, somewhere easy to remove; a thief can take the recorder too.
• Not setting the time and date; when the recording is presented as evidence, a wrong time causes problems.
• Never checking after installation whether recording is actually happening.

Power outage, heat and the notice sign

If the cameras and the NVR shut down when the power goes out, the moment of an incident may not be recorded. Connecting the NVR, the PoE switch and the modem to a small UPS covers short outages. In Şanlıurfa’s summer, an NVR in a closed cabinet squeezed under the counter overheats and the disk gets damaged; put the device somewhere with airflow.

Because you record video with cameras, you need to inform your customers and employees. A notice sign stating that recording is done with cameras is posted at the entrance. Cameras are not placed in places where privacy is expected, such as toilets, changing rooms or rest areas. For the content of the sign and who will have access to the recordings, see KVKK article.

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