Q1: How does motion detection work? Through the camera or software?
Motion detection works through the software in the DVR system by recording video when pixels in the image change. Most Security DVRs offer a sensitivity scale so the user can set the sensitivity of the motion detection.
Q2: 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 .
Q3: 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 320x240 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 640x480 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.
Of course, if you record at 640x480 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.
Q4: What happens when my hard disk 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.