Frequently asked questions about security systems.

General Security Camera Information

Many years ago there were only about five types of security cameras available in the security systems market. Today things have changed considerably. At one time there were only tube security cameras. Today all of the security cameras we use for closed circuit television (CCTV) use a special computer chip called a CCD. These security cameras are a lot more dependable than their tube counterparts, and produce a much better picture. These chip security cameras are much less expensive to produce as well. All of these factors have made the use of CCTV much more affordable and practical for a wider variety of applications than ever before.

What’s a Dome Security Camera?

Dome Security Cameras Among the most versatile types of enclosures. Can be used for both indoors or outdoors applications. Easily accessorized with Pan/Tilt/Zoom capabilities, they offer an aesthetic appearance. Lens are usually interchangeable.

What’s an Indoor-Outdoor Security Camera?

Indoor-Outdoor security cameras for medium to high image quality and flexibility, the bullet security cameras are both cost effective and versatile. They can be installed either indoors of outdoors without any need for a heater and blower enclosure. Pre-equipped with various kinds of lenses, the bullet security cameras maintain a steady (high) temperature within the tiny enclosure.

What Kind of Network Connections Can I Use with the DVR System?

Works with ANY Windows tcp/ip network connection, including Ethernet, ISDN, DSL, T1, Frame Relay, and ATM.

What does Lux mean?

Lux (1/10 of a foot candle) is a standardized method by which to measure a security camera’s sensitivity to light. The lower the number, the less light it will take to reproduce a clear image. For example: A security camera that sees down to 1 LUX, means it generally has the ability to see an image during early evening hours or just before dusk. A security camera that’s down to .1 has the ability to see an image in let’s say, a well lit parking lot. A rating of .05, the ability to clearly view an image in a dimly lit area at night. A .05 image can usually enable a security camera to actually see better than the human eye at night!

Can I Use Any Type of CCTV Security Camera Outside?

Some bullet cameras, Vandal proof Dome camera and most Infrared cameras are designed for outside use with waterproof cases, but if you need lenses of different focal lengths and especially if you need auto-iris lenses (which are best for outside because of varying light conditions) then mini-cams will not be satisfactory. Normally, box cameras are used outside but need to be mounted inside a special outside housing. These housings are rainproof and can also contain a heater unit for really cold climates and/or a fan for hot climates. Mini-dome CCTV security cameras, most Dome camera and some hidden camera meant for inside use only, should not be used outside.

What Does an Auto-Iris Lens do for Me?

Outdoor security cameras or cameras indoors facing a window or an outside door will have varying light conditions. CCTV display and recording systems are set to a certain level of image brightness and contrast. When light levels change in the images produced by the cameras, the displayed and recorded images will either be too bright and washed out or too dark and non-resolvable. The only way to solve this is to use an auto-iris lens. These lenses have an electric motor-driven iris which is opened or closed according to signals fed to it from the camera. Once set, a camera equipped with auto-iris drive will attempt to produce a video signal of constant brightness by opening or closing the auto-iris of the lens, as light levels change.

What is a Vari-Focal Lens or Zoom Lens?

A Vari-focal is a lens that is designed to meet the most challenging jobs by giving the installer the flexibility to adjust between different focal lengths using only one lens. When the situation calls for an odd focal length lens or you are not sure of the correct focal length required for the installation, using a Vari-focal lens is the perfect choice. How many times have you or your installer set-up a job just to be called back because the customer was not satisfied with the field of view of the picture? More than once, most likely. A simple adjustment to the zoom and focus on a Vari-focal lens is all that is needed to rectify the situation on the spot: a less costly and time-consuming prospect than having to order and install a different monofocal lens altogether. Surveillance effects are maximized since any desired angle of view can be obtained

How Far From the DVR Can I Place Security Cameras?

Using RG59 Coaxial Cable, each CCTV security camera can be placed up to 600 feet from the computer and up to 1,000 feet with RG6 Coax. Even longer distances (>2,000’ )can be achieved using Baluns and CAT5 cable

How Many Days/Weeks of Recording Can I Store?

This depends on how big is your hard drive, how many cameras are you using and under what conditions are you recording (on motion, on alarm, continuously, etc.) and what type of compression you are using. Assuming that you are recording only when motion is present (the most common recording method today) using a 30fps board and assuming that you have 4 CCTV security cameras and that there is movement in the surveilled area for 16 hours a day, 5 days a week, and you are recording at 320×240 pixel resolution with MPEG4 compression, you could expect to use up about 20 to 25GB of disk space per week. So, a 40GB drive would hold about 2 weeks of recordings under those conditions. Of course, if you record at 640×480 pixel resolution, and/or you are using a 120fps or faster board, the disk space used will increase. Because of the way that MPEG4 compresses video, there is not a definite mathematical formula that can be applied to say exactly by how much the recordings would grow. Since hard drives are now relatively inexpensive, it pays to use as big a capacity drive as possible (and/or multiple drives) if you are concerned with storing many weeks of recordings before overwriting.

What happens when my hard drive is full?

Normally the system will begin to overwrite the recorded image files, oldest first. You can choose for recording to cascade from one drive to another (i.e if the “C” drive is full, the system can begin to write on the “D” drive), if you have more than one hard drive.