Image of three Dahua dome-style video cameras on a black background


Choosing the right camera for the job isn’t always as easy as you might think. 

While generally “if it costs more, it’s objectively better,” is a guideline that’s hard to fault, it doesn’t factor in your specific need. A camera that can record a mouse winking at 100 metres is obviously a very good product — but if all you want to see is a wall 25 metres away, it’s probably not a sensible choice.

It is important to be clear as to what exactly the purpose of the camera will be. Discuss this with your customer; sometimes their expectations are not achievable or may be outside of their budget. A fisheye camera that provides excellent all-round coverage will perform very poorly at face recognition.

In this article, we will be focusing on lens selection, motion detection, and physical components such as mounts and cables. The advice here is general and all manufacturers will have slightly different interfaces and processes, so you’ll need to consult specific manuals.

Keep in mind, the tips below are not designed to replace training — however, Hills does offer a wide range of comprehensive training courses on product from all our key partners. Talk to your Hills representative about available sessions and your individual training needs.


Lens selection

Cameras with a focal length between 2.8 and 4mm are wide angle, without being distorted (like with a fisheye camera), and are useful for covering large areas for overview surveillance or for covering small rooms with a single camera. 6 to 12mm lenses are good for obtaining increased detail on a specific area of interest indoors — for example, to give clear identification images at a doorway. Lenses of 30mm or greater are excellent for subjects at a distance — for example, capturing license plates down a driveway.

Tools such as field of view calculators are very useful for selecting exactly which lens is required at every location. You can find a link to one such calculator here.


Motion detection

Motion detection is a great way to boost your security and extend the duration of your recording. Motion detection automatically records when movement is detected.  However, some systems will detect any movement — including animals, trees, or even rain. These false alarms are annoying, can reduce readiness for a real security alert — and if your system is monitored, expensive.


Graphic demonstrating different camera view ranges

With improvements in technology and the introduction of Artificial Intelligence (AI), some cameras can even calculate the increased movement of trees in high wind to eliminate over 95% of false alarms. For example, the Dahua WizSense range of cameras and recorders have in-built smart motion detection (SMD Plus), which greatly reduces false alarms by ignoring pets, insects, leaves, branches, raindrops, lights, etc.


Most Network Video Recorders (NVR) will have two locations to configure motion detection: 1. an Event or Alarm section, which lets you configure the area in which you want the camera to look for motion and what to do in the event motion occurs (trigger a notification, switch a relay output, etc.); and 2. a Schedule area, where you can configure how the NVR records at specific times. Some systems will be able to utilise the motion detection technology built into the camera itself, increasing accuracy (as the detection is done pre-compression), and reducing network load. Again, different manufacturers call these menu options by different names, so it is important to consult your manual or attend a product specific training course.

Physical components and connections – it’s not all about technology.

The purpose of the camera will often define the location of the camera. This in turn will help inform the choice of camera style (flush mount for low ceilings, bullets with rain covers for outdoor use, etc.) and will necessitate specific brackets.

Cameras come in all shapes and sizes, so it’s important to understand where each camera is to be mounted. Is it to be mounted to a roof or wall? Is there a building feature that provides an obstacle? Does the mount need to resist extreme temperatures, and does it have a housing to protect cables? Is there a likelihood that something may inadvertently be placed in the camera’s field of view, thus creating a blind spot? Another consideration is likelihood of vandalism. If the camera is somewhere that is at risk of tampering, you need to make sure your mount can resist this.


Many manufacturers provide an "accessory selector" to help you choose the appropriate installation solutions.

Here, for example, is one from Dahua.

Sometimes the ideal installation location for a camera exceeds the standard 100m Cat5e/6 ethernet cable distance. In these situations, consider using a range extending technology such as Dahua’s ePoE. This allows IP cameras to be connected over Cat5 or 6 cable of lengths up to 800 meters.

image of the Dahua accessory selector example screen


Diagrams of Dahua's PoE range-extending technology

The ePoE technology also supports connecting IP cameras over Coax, which is perfect for retrofitting an old analogue site.


Connections are also important. Most people understand that you should weatherproof your connection if a camera is outside, but it’s also a good idea to do this for indoor cameras. Humidity, extreme temperatures, and dust can be just as damaging as rain — and failure to weatherproof connections can lead to camera failure and irreversible damage in some cases. Some security cameras come with waterproof connections, but if there aren’t any included, they can be bought separately.


There is so much to consider when choosing and installing the right video solution. Video surveillance is an integral part of most modern security solutions, and the wrong choice can make your whole system vulnerable. Making sure you have the right solution is relatively simple though. Research the products and the environment in which they are to be used. Communicate with your customer and make sure they understand their options. Some customers think they want something — but if you know it’s not appropriate, you need to tell them. You’re the expert, and they’re relying on you to ensure they have the right solution.

Most importantly, if you aren’t sure, don’t guess. Hills has security solution experts who will be happy to help you if there’s anything you are unsure of — just contact us.