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Frequently Asked Questions

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Cameras

  • How many days/weeks of recording can I store?
    This depends on how big your hard drive is, how many cameras you are using, and under what conditions you are recording (on motion, on alarm, continuously, etc.). Assuming that you are recording only when motion is present (the most common recording method today) using a 120fps system, and assuming that you have 4 cameras and that there is movement in the area under surveillance for 16 hours a day, 5 days a week, you could expect to use up about 150GB of disk space per week. So, a 150GB drive would hold about 1 week of recordings under these conditions. Since hard drives are now relatively inexpensive, it pays to use big capacity drives. All of our systems come with a minimum 500GB Hard Drive Space. Upgrades are always available.
  • Can I use my old cameras mixed with new ones?
    Yes, provided certain conditions are met. Even with the same color type, some older cameras and some newer cameras mixed together can cause problems because of very different image synchronizing systems. In this event, you can get interference between one camera image and another. Color cameras are more prone to this type of problem. Our digital video recording products handle a combination of color and black and white (B/W) cameras.  
  • Why don’t I need 30 frames per second video recording on all cameras?
    Of course, recording frame rates must be fast enough so as not to miss anything - a major problem with multi-camera time-lapse VCR systems. This kind of recording frame rate can certainly miss many things, but a digital system recording at anywhere from 7 to 25 frames per second should miss nothing and still provide many days of recording capacity. There are some applications, however, that do require faster recording rates (e.g. sleight of hand), and we now have the high speed (120fps to 480fps) systems for these purposes.
  • What happens when my hard disk is full?
    When this is the case, the system will begin to overwrite the recorded image files, oldest first. This is one of the great benefits of a digital system vs. the older analog systems. Once the drive becomes full, it is automatically overwritten with new video without any user interaction. You don't have to do a thing!
  • Why are color cameras better than black and white (B/W) cameras at lower light levels?
    Traditionally, B/W cameras were considerably less expensive than color cameras, much more light sensitive, and often of higher resolution. Today, this is not always true. The price gap has narrowed considerably, resolutions are basically the same, and while B/W cameras are still more light sensitive than color cameras, the light levels at which our color cameras will produce images is as low as 0.3 Lux, which is pretty low light.  With these points in mind, color cameras, in most cases, are a better buy today than B/W cameras. A good example of this is our Day/Night vision camera, which works very well in dark settings. Super Day/Night Vision Camera  
  • Lens Chart
    You can refer to the below chart to determine the exact field of view based on lens focal length and distance to the target. For example, a camera viewing a target area 10 feet away will provide the following target sizes:
    • 2.8mm lens = 12.9 feet X 17.1 feet
    • 4.0mm lens = 9.0 feet X 12.0 feet
    • 6.0mm lens = 6.0 feet X 8.0 feet
    • 8.0mm lens = 4.5 feet X 6.0 feet
    • 12.0mm lens = 3.0 feet X 4.0 feet
    The chart can also be used in reverse. By knowing the object distance and the required target area, you can determine what lens is required. Lens Chart  

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