Surveillance varies widely in form and function, since nearly every piece of hardware is designed to suit a specific purpose. A device that will best address the concerns of a bank won’t usually be suitable or necessary for installation in your home. We’ll talk about what questions you should ask yourself when shopping and explain some of the advantages of different solutions. Later, we’ll get into some of the details behind the features and technology. Let’s start by talking about what you should keep in mind before you start shopping.
- What do you want to monitor and where will you be mounting the camera—will you be installing the camera indoors or out, and what are lighting conditions like?
- How will the camera be powered?
- Is vandalism of the camera a concern?
- Do you want to be able to record, or just see what’s going on? If you want to record, how long do you want to store video? How do you want to review footage?
- Will you want to add more cameras to your system in the future?
Form First, then Function
What’s commonly referred to as a box camera is the classic, rectangular camera with a lens sticking out of it that’s been in use for decades. They’re usually customizable, allowing for different lenses to be attached as necessary. Housings are available that can protect them from weather or physical damage, in just about any environment. They tend to be conspicuous, which may be considered an asset if your goal is deterrence, but that can remove them from consideration if you’re considering aesthetics. They’ll also need to be installed with a mount, which often needs to be purchased separately.
Bullet cameras are shaped like a cylinder, usually with their lens on one end and power and video connections on the other. Sizes vary widely, and they’re generally less customizable than other cameras. Lenses are almost always integrated and they aren’t meant to be replaced. They’re available in weatherproof and vandal-resistant housings and run the gamut of features. Like box cameras, bullets will need to be installed with a mount. Sometimes the necessary hardware will be included, but not always.
Dome cameras are generally all-in-one devices that come in a variety of sizes. They can be inconspicuous when flush-mounted in a ceiling or wall, presenting only a bubble, or pendant-mounted. Some domes are darkened to obscure the lens from view and keep observers from being able to tell what they’re looking at, and their design is easy to make vandal-resistant. This makes them popular for loss prevention. “Speed domes” feature pan and tilt capabilities so users can change the direction they are monitoring, sometimes eliminating the need for additional cameras, with more advanced units capable of moving through pre-programmed tours. Installation of some may require cutting into ceilings and walls and electrical wiring work to be done, particularly for “in-ceiling” devices, so check before making a purchase.
Similar in design to dome cameras, turret, sometimes called eyeball, cameras have a similar profile, but lack the protective dome bubble of their cousins. Capabilities are also similar, but they’re usually designed to be more modular, with simple screw-in installation. These cameras don’t lend themselves to vandal or weather resistance and those features are less common. Costs are often lower to reflect that.
Aside from the most common forms, there have been others around for years. Lipstick cameras are, essentially, smaller bullets. Board-cams are pretty much just a sensor and lens attached to a circuit board, sometimes without any sort of case, that are light on features but easy to hide. And then there are covert cameras that can be built into just about any form you can think of.
In recent years, several consumer-friendly devices have hit the market that don’t resemble any of the standard form factors. These are mostly manufactured by newcomers to the surveillance industry and are essentially webcams that are built for permanent or semi-permanent mounting, and are generally lower in price. They’re usually fairly limited in capability when compared to traditional security cameras, trading power, compatibility, and features for ease of use.
Range and Resolution
Your next consideration is how far away you’ll be installing the camera from what you want to monitor, and the quality of video you require. Professionals refer to this as DORI (Detection, Observation, Recognition, Identification), which tells you at what distance you’ll be able to simply detect something moving within the frame and where you’ll be able to see a detailed image. You’ll need to take a few things into account. For recognition or identification, you want to get a pixel density of greater than 60 PPF. There are plenty of calculators available. The chart below is a very rough idea of what pixel density will be using a camera with the most common sensor type.
| Lens Size |
Range in Feet |
||
|
1/3" sensor |
10' |
25' |
50' |
|
2.8mm |
75/110 |
30/45 |
15/20 |
|
4.0mm |
100/145 |
40/65 |
20/30 |
|
6.0mm |
160/240 |
65/95 |
30/48 |
|
8.0mm |
215/320 |
85/130 |
40/65 |
What the Heck is Lux?
One of the most confusing specifications for newcomers to surveillance is lux. Outside surveillance cameras usually present light sensitivity as ISO, with a higher number representing a better sensitivity. In surveillance, we express it as a lux rating, which represents the light levels in the environment the camera is viewing. Technically, 1 lux is equal to 1 lumen per square meter. A camera’s lux rating is the lowest light environment in which a camera will produce a usable image. Practically speaking, this doesn’t mean a lot. It’s a bit of an archaic term and is remarkably imprecise. Because of this, we need to talk about lux in generalities, except in one very important instance.
“Low-light” cameras can generally record below 1 lux. Cameras with sensors that can perceive near-infrared will be rated to record at hundredths of a lux. These are sometimes called Ultra Low-Light or Starlight cameras, among other trade names.
Cameras that are rated 0 lux can record in absolute darkness, which is often referred to as True Night Vision. This is the one instance in which lux has a practical absolute value.
How is that possible? Their sensors can perceive infrared light outside the visible spectrum. With the help of IR illuminators, light sources that are often built into the camera itself, the camera can capture clear video. It’s important to realize that IR video will never be color. By switching to infrared, the camera is only sensing light in a narrow range of the spectrum outside the capability of the human eye. To give us a usable image, it needs to be monochrome. If a camera makes a claim of night-vision recording, check its lux rating.
What About the Weather?
There are a lot of cameras capable of being used outdoors. Look for the camera’s Ingress Protection (IP) rating to find out if it will stand up to weather. The IP rating indicates that a device has been tested to determine its resistance to water and dust. IP65 is the minimum rating you should look for if it will be outdoors. If you’re going to be installing the camera in a particularly rainy or damp environment, look for an IP66 rating. IP67 or higher ratings are granted to devices that can be fully submerged.
Aside from IP ratings, look at the camera’s temperature range, especially if it will be installed in an area that gets especially hot or cold. An outdoor camera won’t necessarily be suitable for use in sub-zero temperatures, at least not for an extended period. If extreme conditions are a possibility, there are many cameras with built-in heaters or cooling systems. There are also enclosures that can be purchased separately to toughen up a device that might not otherwise be suitable for use where you need to install it.
You Have the Power! Right?
How will you power your camera(s)? Pay attention to power specs before making a purchase. Some cameras, particularly those at the higher end that are aimed at professional installers, will require that they be wired directly into an existing electrical system. They may not even include a power supply of any sort. After all, you don’t want to have your high-tech surveillance system defeated by someone who just reaches up and unplugs it or snips a visible power cable.
Many network cameras can receive Power over Ethernet (PoE), which cuts the number of cables you need to run to your device in half. Just check the PoE standard for which the camera is rated, and you’ll need to have a powered switch (or a power injector) attached to the cable at the other end to send power.
Batteries aren’t used very often in surveillance cameras. These devices usually need to be operational 24/7/365, and battery technology still hasn’t caught up with that requirement without needing to be removed and recharged every few days. While solar battery solutions exist, they aren’t what anyone would call ubiquitous, and tend to be costly, aimed at projects like remote construction sites where there isn’t any other power available.
Answer those questions and you’ve got a good start. If you need help, the B&H team is available to help you. There’s a lot to wade through on our website and every situation is different. We’ll help you put together a system that suits your needs.
Click here for Part 2 of our two-part Surveillance Buying Guide.
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