When you have decided that you are going to invest in a CCTV system, then you have to make a number of choices based on these criteria -

The first question is pretty crucial as it will be what shapes all the other decisions ultimately, you need to think about what it is you want to have monitored and where, think about the location, if unsure then you are best off talking to an expert in home or office security and they will be able to pinpoint the potential problem areas and suggest locations to have cameras installed. You may want to monitor a doorway or a back yard for break ins outside work hours or you might want to have a wide angle camera monitoring a car park or you may want a camera watching your till and service area in a shop. Once you have a good idea of the purpose and location then all the other choices are easier to make.

Next you need to think about location although you may have already determined if the cameras are to be mounted outside or inside, outdoor cameras are more expensive to install as they have to be weather proof. Next consideration is daytime or night time...you can get night vision cameras these days that produce incredibly high quality images these days and they are a great deterrent when they are visible, most thieves will simply pass your premises by for an easier target than risk being filmed trying to break in. Another option is to have the cameras on standby until they are activated by movement detecting sensors, meaning less storage space needed for video and so it's easier to find the video evidence you are looking for after an incident.

Once the location and purpose has been established then you need to choose either wired or wireless cameras. Wireless are fine for indoors as they are the easiest to install, they are small and can be placed almost anywhere, they have no wires so are discreet and the video is secure if it is encrypted, most systems are these days, there used to be problems associated with clever criminals viewing the wireless video signal but that is quite rare now.  Wireless systems can be connected directly to your computer network via the router which can be extremely convenient and economical way to improve security in your home or work place.

If you go for wired then you have to have the camera mounted in a permanent location - overall the quality of video signal is better with wired and you never have batteries to replace but these kind of cameras are the most expensive to buy and to install. Also you need to consider the field of view you want the camera to capture, close in or wide angle...

If you go for a fixed camera then you need to ensure that the lens it has will cover the field of view you want to monitor, one option worth considering is go for a fixed camera that has Pan, Tilt and Zoom functions, this will then allow you to have the camera either manually or automatically moving from side to side, up and down and zooming in to get the best view of a particular spot. You can opt for colour or black and white which is always cheaper and often perfectly suitable for CCTV and works well in low light. Colour cameras need good lighting conditions to produce decent images.

And finally you need to set your budget and look for a suitable supplier, remember to shop around and use the internet to compare features and prices.