Hard Drives & Storing Video

Hard Drives Made for Video Surveillance

Recording multiple channels of HD video requires a hard drive that can keep up with the work load. Purple Series hard drives are designed specifically for surveillance video recorders. They can keep up with the work load, assuring reliable and smooth video recording at all times.

The video recorder stores the video footage on internal hard drives. The size of the drive and the recording options determine the total number of days the system can store. There are several variables that affect the total number of days a hard drive can store. The variables include:

  • – # of Cameras
  • – Recording Resolution
  • – Frames Recorded per Second
  • – Compression Format h264 or h265
  • – Continuous or Motion Activated Recording


The number of frames per second you record for each camera can affect the video quality. Live video is 30 frames per second, Hollywood films are shot at 24 frames per second. If you can record less frames per second then you can have more stored days. 15 fps saves hard drive space but produces a slightly choppy or robotic motion in the video. 20fps is the best bang for you buck, the video is smooth and 20fps requires 33% less hard drive space compared to 30 fps. If you are attempting to capture moving license plates, you will need to record in 30fps, otherwise the plate capture will be blurry.


The security industry has settled on two video compression formats. They provide the ability to record high quality video into smaller compressed data files. The first used was h.264 which is standard now and all video surveillance recorders support this format. Recently h.265 has been released which reduces the file size up to 40% compared to h.264. Clearly the compression format you use will affect the total number of stored days.


Each camera can be programmed to record continuously on motion activation, schedules or a combination of the two. Expect to double your stored days if using motion activated recording compared to continuous recording.

Home Security Camera Placement

Camera Locations

The following are suggestions, they may not apply to every installation. Before you start installing, walk the areas where you plan to locate the cameras. If possible, stand at each camera’s location. Pay attention to what you see. Can you see everything you want to at that location? Whatever you see, the camera will see. If the answer is no or if there is an obvious blind spot, look for a better location for the camera.

Indoor cameras can be installed just about anywhere. Wall or ceiling mounted is fine. Typically, cameras are installed in a corner of the room opposite from the entry point. This usually provides the best coverage and requires anyone who would want to tamper with the camera to be recorded before they have access to the camera. The best height for a camera is usually around the 10ft level or higher. This is high enough to keep people from accessing the camera unless they have a ladder. Also, understand if you aim a camera at large exterior windows or an exterior door, the view may be somewhat limited during bright or sunny days. All cameras are equipped with an auto iris and they work extremely well, but they still have their limits and will have to adjust to either the light level inside or the light level outside. Whichever one it adjusts to, the other will likely be less than optimal.

So where should you locate your security cameras?

Below are a few of the most common viewing patterns. Each has benefits and possibly some draw backs. Your application will dictate which design is most effective.

Mid Wall Pattern

Mounting a camera mid wall and adjusting its view perpendicular to the wall. This location can be useful for certain applications but is seldom used by security professionals, simply because it creates a blind spot on each side of the camera. A 3.6mm lens provides the widest viewing angle without distorting the image. There are 180 degree cameras on the market but they distort the video so badly that the video is useless at distance. We do not recommend using any lens wider than a 2.8mm, which provides a viewing angle of 110 degrees. Still, with such a wide viewing angle, do not expect great clarity beyond 40 feet (there is a warping or bubble effect past 40 feet). Because of this, a 2.8mm lens should be used for up close applications – such as a porch or any location where you desire a very wide angle view but do not require great detail at distance.

Back to Back Pattern

Place two cameras back to back mid wall. This design eliminates the blind spots that can occur when using one camera mid wall.

Secret Service Pattern

Two cameras are installed on the same wall, separated by 15-20 feet and aimed towards each other. Basically, the cameras are watching each other’s back so that neither camera can be disabled without the perpetrator being seen. This design works well with both fixed view and zoom lens cameras.

Corner to Corner

This design is the most common and provides several benefits. It makes the most of each camera’s viewing capability and covers 100% of the perimeter. When the cameras are placed as the diagram below indicates, all blind spots are eliminated and the cameras cannot be vandalized without the perpetrator being recorded by another camera.

Inside Corner

This pattern is simple and very effective. Because a 3.6mm lens provides a 90 degree field of view, it is perfect for an inside corner. When using this method, the camera cannot be vandalized and the corner is covered wall to wall.

How to Wire Your Home for Security Cameras

Dome or Bullet Style Camera, which should you choose?

Note: Less than half of residential systems have indoor cameras. Properly placing cameras outside on the perimeter of your home can be just as effective as indoor cameras without giving up privacy.

Outdoor cameras follow the same basic guidelines as indoor cameras. While they are designed to handle weather, the elements and can operate in extreme conditions, it is still preferable to protect them if possible as they will certainly last longer. If you have the options of mounting the camera directly on the roof, where it will be taking the full brunt of the sun, rain and wind – or on the side of a building where it is somewhat sheltered, always choose the side of the building.

Don’t ask one camera to do the work of two!

The most common mistake customers make when locating cameras is trying to get one camera to do the work of two. We all want to get the most out of each camera, but if you go too thin with coverage, you may be throwing your money away. We have all seen video of some crime being committed, but due to the lack of detail that the video provides, the cuprite cannot be identified. The lesson learned is “Be conservative with the coverage you expect each camera to provide”. As a general rule, each camera should not be expected to view more than 30-40 feet horizontally at the preferred viewing distance.

Good & Bad Security Camera Installations Rated

Typical Residential Camera Placement

Cameras located at the corners of the home in a trap surveillance pattern is common practice and is very effective. Trap surveillance is the most cost effective form of indoor surveillance. Cameras are strategically placed so a person cannot move from one area of the home to another without being seen and recorded. This design reduces the number of cameras needed to effectively protect the inside of a home, while keeping bedrooms and baths private.

Understanding Resolution & Frame Rates


There are many aspects to resolution, but for our needs, we’ll keep it simple. Resolution is simply a way to measure the size of the video being produced. Smaller images produce low resolution video, larger images produce HD or high definition video. It really is that simple. The larger the image being recorded, the higher the resolution and quality.

Resolution is measured in pixels. Then pixels are grouped into categories such as 2 megapixel, 4 megapixel, 5 megapixel and 8 megapixel. These categories are then simplified into 1K, 2K, 3K & 4K categories. This is intended to make things easier to understand but it often confuses the average shopper. The cart below will help clear things up.

Frame Rate or “Frames Per Second” FPS

The frame rate is how many individual images the camera produces every second. Hollywood movies for example are filmed at 24 frames per second. What we consider “live” video is 30 frames per second. Interestingly, the human eye has difficulty seeing the difference between 24 and 30 frames per second.

Why does this matter? The answer is cost. HD video produces huge amounts of data and large hard drives are required to store all that data. So why record in 30 frames per second if our eyes cannot tell the difference between 24 and 30 frames? By recording in 20fps you just dropped the hard drive size by 33% or increased your storage capability by 33%. Also, cameras that produce 20fps are generally lower cost than cameras that produce 30fps.

Have no doubt, the best video performance is produced with 4K cameras at 30 frames per second, but if you value cost over performance, consider 2K & 3K cameras with 15-20 frames per second. The video samples below provide a visual comparison.

30 Frames per Second – 4K

15 Frames per Second – 3K