If you record video in your home or business there are some tips that will assist us in the event that your video might one day be used as evidence in a court proceeding.

These tips apply equally to large multi-camera installations as they do to a simple camera connected to a VCR.

The first thing to know is that most of what you see on CSI (fictional TV drama about forensic evidence collection) is fiction. No, we cannot 'extrapolate' a person's face from reflection off a lampshade across the room or from a reflection off your cornea. Nor can we identify a person in the back corner of a video and zoom in on them to have them magically materialize in vivid detail. We wish we could, but this is just not possible, especially with the low resolution security cameras, low frame rates, poor camera positioning, bad lighting and high compression found in today's typical security camera video.

That being said, we don't expect you to install IMAX cameras and high-definition video recorders in your business, complete with a crew of sound and lighting engineers either.

There is a famous line in the movie 'Jerry McGuire' where Tom Cruise's character states emphatically, 'HELP ME HELP YOU'.

That is the purpose of this article. We figure that if we want you to collect good quality video for us, we should tell you how to do just that.

Since most people record video to protect themselves, their property or their loved ones and to document evidence in case they are victimized, you might want to know what can you do to collect the best possible video?

Camera Placemement If you expect to use your video to identify a person, you need to capture their head and face. I know this sounds like common sense, but most of the video we get is taken from a high angle, far above the person we need to identify. Without being able to identify a person’s face, you are only recording the fact that a 'person' was there.

Compression Is Bad (but unavoidable) Most digital video recorders (DVR) use variable degrees of compression to shrink the size of the video to maximize storage on the internal hard disc. On the other hand, VCR recordings are completely uncompressed. Compressing a video results in a video of not only a smaller file size, but of lesser quality and detail. In addition, since compression actually discards information to compress the video, you are not recording all that your camera is actually capturing. Few DVRs actually allow you to turn compression off, but you can control to what degree (how much loss) it will compress your video. Consult your manual or check with your installer for help in reducing compression and increasing the video frame size.

Hard disc drives are cheaper than ever today, so whenever possible, set your DVR to record the largest image size at the least amount of compression. You will use up more hard disc space and may not be able to keep as many days or months of video but what you do have will be of higher quality and of higher evidentiary value.

Lighting Another fact, security cameras need light. Cameras used to record in dark environments are usually sensitive to IR (infrared) light and have some form of illumination. Well-lit scenes are always going to give you better video. Conversely, too much light will make your camera’s image ‘washed out’ and steps to adjust the camera’s iris are necessary. Ensure your camera view is clear, well lit and is not aimed into an area where light changes dramatically.

Color vs Black and White (grayscale) Color cameras provide more details. Determining a person’s skin tone, hair color, clothing colors etc. is only possible when using a color camera. Color cameras need more light to capture these details.
Black and White (or grayscale) cameras are better suited to low light areas. While some important information is not available from a grayscale image, the quality is superior in low-light or artificially lit (infrared) night recordings.

Multiplexing This process allows multiple camera views to be recorded onto a single VCR tape. The result is a stop-motion effect where each camera’s image is recorded on successive frames (or fields) that, when viewed on a system without the multiplexer, appears to be images flashing by at an imperceptibly high speed. The benefit of being able to record several camera sources on a single tape is offset by the fact that there are many frames of data missing from the final result, so when isolating a single camera’s view, even when slowed down to approximate real-time, the images have a strobe light effect and motion is not smooth.

Another way of recording is called Quad. This is where a video display is broken up into four quadrants and images are all displayed simultaneously. While this allows for non-multiplexed full motion video, the images are small and only occupy a fraction of the screen. This presents problems when trying to get details from a single camera. Once the video is recorded in this format, a single camera view cannot be isolated without distortion from zooming in.

Summing up, we recommend that you talk to your camera installer about these issues, review your operating manual to become familiar with your system’s settings and take steps to ensure that you are not wasting your time capturing video that may result in disappointment when you really need it.

If you record to VHS tape, you need to invest in new tapes every 6 months. Don’t just keep re-using the same tired old cassette until it jams up in your recorder. The magnetic particles on the tape are susceptible to wear and tear and cannot be relied upon to serve you well for any great period of time. In addition, pausing playback and scanning forward and backwards while paused will cause your tape to wear even faster.
A worn tape stores poor quality video and creates many unnecessary challenges for our video analysts; some of which can result in us not being able to use what little video you managed to record.

If you have any questions or comments about this article, feel free to contact S/Cst Bill Gordon at (705)526-2201 ext 2310.