When considering the recording capacity for your security system, it is very important to consider two things: motion or continuous recording and how many days of continuous recording you are trying to accomplish. It is also important to understand how motion recording works and how the camera’s environment affects motion recording. It is very crucial to remember both motion detection and continuous recording record for 24 hours a day.
Both motion and continuous (aka 24 hour) recording work by using H264 compression. Unlike continuous recording, motion recording does not record unnecessary events. Using H264 standards, motion detection works by comparing the first few images (i-frame) against p-frames or subsequent changes in the image. Since H264 ignores the stationary objects: houses, parked cars or trees in the images and only uses changes in the motion-blocks in the frames for recording, motion detection saves both bandwidth and recording storage. When you are using motion recording, your security system is always recording in the background as a buffer.
When you’re setting up a motion detection camera you have to be mindful of few things. Motion area, sensitivity of the motion detection and initial-post recording. Motion area is as important as motion sensitivity because both determine when the recording will start. When setting up the motion area, it’s important to limit the motion active area in the video so you can achieve greater savings in your recording storage. However, motion sensitivity is not as straight forward as the motion area. Most security systems use a range of numbers to determine how their motion detection algorithm works (some variation of H264 standard). Usually, 1 represents the lowest sensitivity which gets progressively higher as sensitivity increases. Based on your selection, the security camera system will use the camera’s field of view to determine when an object can trigger the motion recording. For example, for a small area like an indoor room or backyard you can use a medium setting of motion sensitivity range. For large areas like halls, auditoriums or outdoor scenes, the objects in the field of view of the security camera will be small; this makes it necessary for one to use settings that are higher when determining the camera’s sensitivity.
Lastly, your security system usually has a section in the recording sub menu where you can adjust when the motion recording should start and stop. This way, when you play back a motion recorded event, you will see footage before the object has triggered the motion sensor and after it has ended.
Motion detection works best in small areas and it’s ideal for residential or retail environments. Although, for larger areas such as outdoor parking lots or inside a warehouse, it is recommended for one to use a 24-hour recording setting. The good news is, most security camera systems have each channel recording independent from one another. This allows you to use a mixture of motion detection for some cameras and continuous for the other cameras.