Should You Use PTZ Cameras?

Though popular, PTZ cameras often create a false sense of security. They make for great demonstrations but are often underutilized or misused.

The use of PTZ cameras varies significantly. Offices and fast food restaurants rarely use PTZ cameras. However, the majority of cameras at shopping malls and public surveillance are PTZs. In general, PTZs are the standard choice for monitoring large public areas.

Here's a short video demonstration of using a PTZ:

Advantages of PTZs

• Monitoring large areas: the PTZ camera can be panned, tilted and zoomed to cover hundreds of acres (a few square kilometers). This is not possible with fixed cameras which normally only cover a small area (few hundred square meters).
• PTZs can be placed on tours (patterns) that move the camera in a predetermined way to capture areas of interest. For instance, over a 1 minute period, the camera can capture the front door, the gate to the parking lot and the fenceline. The tour can repeat indefinitely.
• Operators can control PTZ cameras to track a suspect or respond to a security incident. The operator can zoom in to view and capture fine details like facial features or license plate. The operator can also follow a suspect across a large area.
• Because PTZs can cover a wide area, this reduces the cost of coverage per given area.
• People love PTZ demos. They are the closest thing the surveillance industry has to movie special effects (see the demo above). It makes people feel excited about the potential.

Alternatives to PTZs

Megapixel IP cameras are emerging as an alternative to PTZs but issues remain.

The primary potential of Megapixel cameras is to eliminate the problem that PTZs can only view/record where they are currently looking. By contrast, since megapixel cameras use a digital zoom, viewing does not impact the area recorded. Also, since megapixel cameras eliminate the mechanical complexity of PTZs, their cost is lower (even for multi-megapixel) and the service issues should be less.

However, megapixel cameras cannot come close to matching the potential coverage area of a PTZ camera. Even with the far higher pixel count of a megapixel camera, it's unlikely to provide anything more than the equivalent of a 2x or 3x optical zoom. Furthermore, while megapixel vendors contend that megapixel cameras provide the resolution of 20 to 60 standard definition cameras, the effective image detail is nowhere close to this (especially at lower light conditions).

While megapixel certainly offers enhanced resolution and coverage area over fixed cameras, there's little reason to believe that megapixel is or can eliminate the use of PTZs.

Best Fits for PTZs

With these considerations in mind, PTZs work best when:

• An organization has operators dedicate to monitoring security systems. If you are a big box retailer or a sports stadium and have operators dedicated to monitoring, PTZs make sense. The PTZ cameras allow operators to monitor greater areas. However, if you rarely monitor the security system and primarily use it for investigations, megapixel cameras are a worthwhile alternative to consider.
• An organization has a really large area that needs to be covered. Such large areas may still be impractical even with megapixel cameras. Only a PTZ provides you the range needed (so long as you have active monitors). However, if you have a moderate size area (like a parking lot with a few dozen spaces), one or two megapixel cameras are likely to be less expensive and more effective.