When a lens is focused on an object, theoretically, the whole plane passing through the object and perpendicular to the optical axis should be in focus. Practically, objects slightly in front of and behind the object in focus will also appear sharp. This “extra” depth of sharpness is called depth of field. A wide depth …
Images can be constructed by using simple optical and geometrical rules. As can be seen on the following drawing, at least two rays are used to create the image of an object. There are three basic rules to follow: Objects taken at various distances touch the optical axis with one end. By definition, rays that …
When a light ray traveling through air or a vacuum enters a denser medium, it reduces its speed by index of refraction. Different media (which are transparent to light) have different indices of refraction. For example, the speed of light in air is 300,000 km/s and almost the same as in vacuum. If a light …
Sensor sizes are specified by the diagonal and mainly include 1/4″, 1/3”, and 1/2″. A lens can fit in with a smaller sensor. When using with a larger-sized sensor, for example, a 1/4” lens with a 1/3” sensor, the situation of dark corners in the image will be caused.
A camera with WDR wide dynamic range is able to operate in variable light conditions, especially in high contrast situations. When shooting in high contrast, backlight, glare and light reflection environments such as the entrance, ATM or the window side, the object will appear dark and unrecognizable. WDR (Wide Dynamic Range) technology can ensure an …
Video manager software mainly includes web-based software and central management software. Webbased software is built in the camera, allowing users to perform basic functions such as recording, monitoring and configurations. Relatively, central management software offers more powerful functions such as playback, remote monitoring in multiple monitors etc., to achieve efficient, flexible video management. Monitoring Users …
An NVR (Network Video Recorder) is an IP-based recorder that operates independently from a PC or other operation systems. Aimed to store digital video streams from network cameras, an NVR is usually incorporated with a large-volume hard disk to allow for a long period of recording. An NVR differs from a traditional DVR in its …
As CCTV is part of a multi-layered security approach, a CCTV system design should begin with a comprehensive needs assessment to ensure security risks and mitigation plans are identified. Clear requirements, a comprehensive site survey, and proper equipment selection and installation must all be considered when designing a CCTV system. Identifying Customers Needs Before deploying …
in order to achieve efficient video transmission, it is important to evaluate your bandwidth requirements before setting up an IP surveillance system using cctv storage calculator. Bandwidth requirements in cctv storage calculator vary with the following factors : Resolution: the higher the resolution, the more bandwidth is required Complexity of the scene: the more complicated …
A network camera, also known as Internet camera, IP camera or Internet video camera types , transmits live digital video over an Ethernet network to back-end devices such as a PC or 3G phone. With a dedicated IP address, a built-in web server and audio/video streaming protocols, it can work independently for real-time monitoring Introduction. …