Video Security Definitions
4K: is a broadcast standard that defines image capture that has 4,000 vertical pixels in image, which has been a long established minimum resolution standard for Professional Broadcast Video recording and transmission. Contrast that with “Standard Definition” which was only 420 vertical lines (or pixels in digital terms).
So any camera rated as a 4K camera is high enough to meet quality professional broadcast resolution and recording minimums.
Box Cameras & Brick Cameras: Any size of fixed cameras that have Box or Brick shape. This was the traditional form factor of video camera, which was the most popular form factor of surveillance cameras till mini-dome cameras took that title around 2005.
Bullet Camera: It originally referred to small form factor cameras that are roughly look a lip stick case, but now can include tubular camera as big a 3” or larger diameter tube shaped camera, typically with built in wall or surface mount bracket integrated to rear of camera tube. It includes “Lip Stick” small form factor cameras, to much larger form factors of similar shape.
CCTV: Closed Circuit Television. An Analog video technology. The term is virtually obsolete, as most new analog systems now are hybrid Analog, therefore are not closed circuit – but rather open to the internet on back end portal thru the Hybrid DVR; Therefore, not closed circuit. Also, TV part of the acronym designation is now is now more generally referred to as Video monitoring. Hybrid Analog, HD-TVI (analog), and IP Surveillance looks to be the future of what was formerly referred to as CCTV analog, as well as on the higher end, IP based Network camera on the higher end of surveillance needs.
Digital Zoom: Is a software cropping of image in camera FOV / Field of View, in contrast, see Optical View definition..
Fixed Cameras: Any camera that is fixed in viewing angle, and it includes many form factor of cameras including box, brick, mini-dome, bullet, turret, and dome cameras. Some may have digital Pan Tilt control (lens is fixed, but software crops view to user), and some have digital zoom (lens is fixed, but software crops and expands FOV).
Forensic Video Capture: Quality video resolution to provide enough detail that is usable to clearly identify people or subject behavior & object identity to use as legal evidence, commercial behavior analysis, or for scientific video subject analysis.
FOV (Field of View): Think of it as the picture frame if what the camera pics up. Focal length of cameras lens, the size of imaging sensor built into camera, and distance that camera will be from target scene will all influence field of view. Field of view should be a primary consideration on what camera you choose. It helps refine lens types to choose, sensor size, and how high of resolution you need to meet target clarity of video.
HD: High Definition; for IP video this starts at 720p (number of vertical pixels in image), then 1080p, and then moves to the Megapixel (MP) rating standard, where 1 megapixel is roughly 1 million pixels in entire image captured. Analog & Hybrid systems adopted the HD equivalents rating to compete with HD IP / Network video.
The following table roughly equates digital resolutions.
720p=1MP, 1080p=2MP, then 3MP, 4MP, 5MP etc.. There are commercially available cameras commonly up to 20MP, and even more. One Notable resolution is 9MP = 4K. See “4K” for explanation and significance.
HD-CVI: is a proprietary Dahua (China) hybrid technology, because they are only compatible with HD-CVI DVR’s and expense is similar to IP, industry is skeptical of it as the future resistant technology.
HD-SDI: is a proprietary Dahua (China) hybrid technology, because they are only compatible with HD-SDI DVR’s and expense is similar to IP, industry is skeptical of it as the future resistant technology HD-TVi: Yes it sure looks like TVL, but TVI with last letter I, is an Analog hybrid technology compatible with a wide range of non-proprietary Analog and Hybrid DVR’s. It means High Definition, Transport Video Interface sends video, audio, and data signals thru standard cctv coax, with distance over coax for up to 500 meters. Compare to IP cameras that are limited to 100 meters over Cat 5/6 cable.
H.264: H Dot 264 is a digital transmission compression codec that reduces bandwidth over motion JPEG streaming bandwidth.
Lens Types: Fixed, and Varifocal:
Fixed lens has a fixed cone of view angle captured by focal window… It is significant because each camera needs to be optimized for either wide angle overview of scene, or specifically on a smaller well defined area. It has a great affect on detail captured by camera and resolution of camera is significant to get needed detail. The wider the field of view, the less the effective resolution of small areas of the image. If fixed focal length is more zoomed into a specific area, the detail is much higher, but at the cost of missing overall image outside the FOV/ field of view.
Varifocal, means you can change from wide angle focus, to a zoomed in focal length and anywhere between.
Optical Zoom: Is a remote control mechanical zooming lens via the cameras video interface. Allowing changing of FOV in and out, via lens focal length control, which not only affects FOV, but also image magnification or reduction with compound lens adjustment..
PTZ Camera type: Any size or form factor of cameras that can be remotely controlled via Internet, or wired controller that allows camera to be controlled from a distance that camera views can be controlled on the X, Y, and Z 3D axis, as well as zoom control. Basically a robotic cameras that can view can be controlled by Panning left and right, or Tilt viewing angle that can be controlled to view up, horizontal, or down, and lens Field of View can be controlled for wide angle, to zoomed in focus.
Turret Cameras: Are a form factor of camera that typically have a round eyeball shaped camera shape, with an integrated flat wall / surface mount bracket that surrounds and seats the camera that creates a turret that allows nearly any type of camera mounting and positioning in integrated turret mount seat. They can be as small as 1” diameters up to 6” or larger diameter camera ball.
TVL: TV Lines / Television Lines are horizontal lines on Image, which are scan refresh lines on image. It is used in the analog & hybrid cctv resolution / image quality rating system. The higher the number, the clearer the video is. Standard definition at low end is 420 TVL, while 1,000 TVL is roughly equivalent to 1080p (1080 vertical pixels) in video image of comparable IP camera rating system.
DVR: Digital Video Recorder is a recording device for Analog based camera technologies
NVR: Network Video Recorder is a specialized Recording computer for IP based camera technologies.
VMS: Video Management Software installed on NVR’s to record and manage multiple video streams for record, monitoring, and managing of IP surveillance video.
PoE: Power over Ethernet, which uses Ethernet cable to power end device as well as transmit via a Cat5/ Cat6 cable. Also known as low power, 14 watt for end device, as defined by IEEE 802.3-af standards, using 2 spare pair wires on Ethernet cable to transmit power, and remainder to transmit data.
PoE+: High Power PoE, as defined by IEEE 802.3-at standards of up to 24 usable watts to end device, using all four pairs of wires in Ethernet cable to transmit power, along with data.
IP Video Technology & Cameras: It is an internet base video managed and transmitted. It shares data pipeline with your Cat5/ Cat6 Ethernet computer equipment. Generally speaking, cost of IP cameras are 2-3x higher, or even more cost then analog or analog hybrid HD-TVI, or fully Analog CCTV technologies. IP video has generally adopted High Definition standards as baseline resolution, of 720p, 1080p, or even higher megapixel resolution. Though many brands and resolution cameras can be combined on the same system, it requires a software VMS (video Management Software) which is pricey licensed software, typically annual re-occurring cost Software as a Service model (SaaS) which adds to cost. If you stay within a same brand of cameras, most manufactures offer free software compatible with only their camera models for small systems (up to 3 – 16 camera licenses), depending on manufactures. A couple manufacturers allow unlimited licenses with purchase of their cameras.