Dome cameras — Designed to blend into any environment, these models feature a compact design. Dome casing safeguards against redirection, defocusing and impact. Camera direction is always concealed. Good for indoor and outdoor settings, dome cameras can be used day and night.

Box cameras — Boasting conspicuous, rectangular shapes, box cameras deter unwanted activity by their very appearance. Potential offenders know they’re being watched. Operationally, they zero-in on areas where precise monitoring is critical. These models are suitable for a range of outdoor/indoor applications, providing clearly visible, fixed angles of view.

Hidden cameras — Small and unobtrusive, hidden cameras can be installed in a variety of indoor/outdoor environments that require covert surveillance. Since they’re unseen, these models cannot be vandalized, covered or harmed by offenders. HDTV image sensors, thermal technology for intrusion and more advancements make them powerful options for today’s security toolbox.

Bullet cameras — Bullet cameras feature slim, bullet-like designs to achieve long-range viewing. They offer discretion for any environment. Bullets are good for all-purpose surveillance needed 24-7, indoor or out.

PTZ cameras — Known as pan-tilt-zoom, PTZs enable remote control of direction and zoom for exceptional coverage of large areas while tracking movement with superb detail. PTZs are found in places that require round-the-clock coverage that’s fast and precise, such as airports, train stations and arenas.

360 cameras — These “fish-eye” devices use multiple lenses to capture the target location in all directions, offering panoramic viewing. Models with PTZ capability enable examination of specified areas at different zoom levels. Today’s 360s produce extensive views without blind spots.

When researching security cameras, consider specific features and specifications, such as:

Higher resolution for clearer and more detailed high-quality images.

Infrared LEDs to capture clear images in low light or darkness.

Weather resistance such as housing or casing to withstand the elements, including extreme heat, cold and moisture.

Wide dynamic range (WDR) to balance exposure in scenes with both bright and dark areas.

AGC can select from a variety of security-camera models with interchangeable lenses. The correct lens depends on the situation that requires monitoring among such variables as budgets, threat levels, etc. The following lens topics can assist clients in their understanding of best options.

Focal length — Measured in millimeters, the distance from the lens’s center to the point light rays from an object converge or come into focus. The shorter the focal length, the wider the view but with less detail. The longer the focal length, the farther the view but with a narrower angle.

Aperture — The size of the opening whereby light enters the camera. Measured in F Stops (i.e., F1.4), aperture values affect depth of field or the distance between the nearest and farthest objects in a scene. Lower numeric values represent wider aperture.

Iris — The iris controls the amount of light entering the aperture. When the iris creates a large opening, more light passes through. Wider openings do not always mean better images. Excessive light can wash out video coverage. Inadequate light can result in dark scenes. Fixed and manual iris lenses are typically used for an indoor environment with consistent light. The auto-iris lens can adjust for light changes, making them idea for light variations in outdoor locations.

Camera format — Refers to the lens’s image sensor, a spec listed as fractions of inches, such as 1/2”, 1/3” or 1/4”. The smaller the image sensor, the narrower the field of view. The format size of a security-camera lens should be equal to, or greater than that of, the camera’s format size. Otherwise the corners of the scene will be cut off.

C or CS mount — C and CS mount are options for mounting a lens to a security camera. Their main differences lie in the distance from the image sensor to the lens. The C mount distance is 17.5 mm, and CS mount is 12.5 mm. When selecting lenses for security cameras, check whether the lens and security cameras allow for C mount or CS mount. Not having a matching lens could result in poor image quality.

Varifocal lenses — With varifocal lenses, the focal length (distance in millimeters whereby light travels from the lens to the camera’s backend focal point) adjusts for specific needs. Users zoom-in for closer views. Zooming out enables wider views. Compared to fixed lenses, varifocals tend to be more expensive. They are used typically to monitor large areas and capture closeups of people or vehicles. Typical settings are front and backdoor surveillance, garages, parking lots and construction sites.

Two main categories:

• Manual zoom — The focus is adjusted manually by moving a dial or switch.
• Motorized zoom — The camera’s focal length adjusts automatically to capture clear images at different distances. Most varifocal-lens security cameras are motorized for convenient operation, such as PTZs. The zoom can be adjusted via mobile software or desktop client.

Fixed lenses — In contrast to varifocal lenses, the focal length for these lenses is fixed permanently. Image size is fixed no matter the distance between the viewed object and camera. Fixed lenses often monitor interior space or stationary areas.

Two main categories:

• Wide-angle — These lenses have a short focal length to capture a wider field compared to normal lenses. Security cameras with a 2.8mm lens capture 100-degree wide viewing angles. For even wider views, specialized cameras employ dual lenses to capture a 180-degree wide view.

Telephoto — Long focal lengths enable telephoto lenses to capture distant objects with sharp clarity. They are deployed typically to monitor long hallways or fixed points within vast facilities.

Video data contains a tremendous amount of information. When digitized, it can consume large amounts of mega-bits-per-second (Mbps) of bandwidth, making it impractical to transmit over an IP network or cost effective to store. Video compression techniques reduce the bit rate or the number of bits-per-second transmitted over a digital network. The goal is to reduce as much data as possible without diminishing video quality.

Compression software formats are known as codecs, an abbreviation of compressor-decompressor or coding-decoding. These programs compress data (a process called encoding) to enable faster network transmission then decompress it for playback. The industry’s most familiar codec standards are version H.265 and its predecessor, H.264.

• Codec H.265 and H.264 — The latest advancement in video encoding, H.265 is a standard known as High Efficiency Video Codec (HEVC). It delivers 25 to 50 percent better compression than H.264 at the same level of video quality.

Codec software compresses video by dividing the video’s pixels in blocks called macroblocks. H.265 encodes macroblocks ranging from 4×4 to 64×64 pixels. H.264 encodes blocks of up to 16×16 pixels. With a top pixel range that’s four times higher, H.265 provides better motion compensation and prediction technology to enable lower bit rates; users can thus stream more cameras within a 10 Mbps pipeline.

Storage savings and video quality
Before the advent of H.265, users had to decrease camera resolution and frame rates to achieve lower bit rates. However, poor image quality often resulted. H.265 encoding offers the same image detail at half the bit rate. A 4K security camera in H.264 will record at approximately 8 Mbps; using H.265, it can record the same quality at 4 Mbps. As a general rule, a rate of 6 Mbps for H.265 4K is recommended to avoid video artifacting or image glitches that occur during encoding. (Note: no matter which mode is used — H.265 or H.264 — a bit rate that is too low for a given resolution and frame-rate will cause video artifacting.)

Longer recording times — A system using H.264 will record seven days before overwriting old footage. The same system with cameras set to H.265 encoding would record 14 days before overwriting begins. Keep in mind 25% percent savings on average is a reasonable expectation, which means 10 days before overwriting. How much you save depends on how low the bit rates are set for each channel before quality loss is noticed.

Lower internet speed and data requirements — Lower bit rates allow transmission of video streams over slower internet connections. Most apps use the lower-resolution sub-stream by default to save data and work around slow internet speeds. The lower bit rate for H.265 means that users can switch to the high-resolution mainstream without using as much data and on slower connections.

More Wi-Fi cameras — Since H.265 requires less bandwidth for data transmission, it means Wi-Fi cameras don’t require as much throughput to transmit video wirelessly. This results in the ability to connect more Wi-Fi cameras to an access point or wireless router. In the past, it was recommended to only connect a maximum of four Wi-Fi cameras to a single access point using H.264. Setting the encoding to H.265 on the camera enables connections of 6 to 8 Wi-Fi cameras to an access point.

More processing power required — The increased efficiency of H.265 requires greater processing power to encode/decode video, which will slow down the DVR or NVR. With H.265 decoding, a PC with a powerful central processing unit (CPU) — such as 4 or 6 cores — would be required to playback one camera at a time.

Playback compatibility limits — Since H.265 is not as universal as H.264, some PCs and smartphones may need a third-party plugin to achieve playback compatibility. Free media-player software (such as VLC and the K-Lite codec) do not always support H.265 on all computers. In 2018 Microsoft started charging 99 cents for H.265 support on Windows computers. Fortunately, most iPhones and Androids include free support for playing back H.265 videos.

Camera and recorder compatibility — There are still some cameras and DVRs or NVRs that do not support H.265 encoding, particularly when mixing brands, vendors or manufacturers. Cameras and recorders need to be equipped with the ability encode and decode H.265 video. Refer to camera and recorder specs to confirm such support. Additionally, H.265 encoding connected via Open Network Video Interface Forum (ONVIF) can be problematic when mixing cameras and NVRs from different manufacturers.

To save more space and bandwidth, surveillance-equipment manufacturers developed proprietary codec improvements known as H.265+ and H.264+. Also called smart codecs, these technologies predict bit-rate adjustments in real-time based on improvements in how they frame moving objects against a scene’s stationary background. Since they’re proprietary, each version requires deployment of power-over-ethernet (POE) cameras and NVRs from the same manufacturer.