FBI CCTV RecommendationsBy John Honovich, Published Mar 10, 2012, 07:00pm EST
The United States FBI provides a CCTV Best Practices guide in a unique form of a TV show episode. In this post, we review the FBI's recommendations, providing feedback and commentary on what is realistic and what can best be done to improve commercial surveillance systems.
The video, watched over 60,000 times, is embedded below. At 21 minutes long, we found the most useful CCTV recommendations between minutes 3 and 12:
While the video is interesting and the recommendations are worth considering, the biggest challenge we see is the cost of them. If money was no object (as it is for the FBI), many of these recommendations would be great. Unfortunately, many are hard to justify economically.
In the rest of this report, we analyze 13 key recommendations made by the FBI, providing our input.
One of the first things the FBI notes is the common problem of washed out images at entrance doors. The snapshot below from the FBI video demonstrates this:
The category of camera that addresses this problem is called WDR or Wide Dynamic Range. WDR is definitely a valuable feature to use especially for outdoor entrances.
Making the best use of WDR can be challenging. Keep these pointers in mind:
- Expect to pay a premium: Cameras with WDR tend to be $100 - $250 USD more than cameras that do not.
- Beware of marketing claims: Any vendor can claim their cameras have WDR and many do even when the performance benefits are minimal or nonexistent.
- MP cameras have the best WDR: If you want the strongest WDR, our tests show that top MP cameras significantly outperform their top SD counterparts.
- Stay Up to Date: Our ongoing testing series has a MP WDR shootout as well as comparisons of new cameras claiming WDR - Pelco SureVision and Axis Q1604.
Next, the FBI comments on problems with cameras being obscured, demonstrated in the clip below of a marketing sign blocking out a suspect's face.
From time to time this does happen. Typically, no obstructions exist when the system is first installed. At that time, the security manager usually reviews and adjusts camera angles and signs to eliminate this problem. However, later on, new signs or furnishings may be installed. For instance, Christmas decorations can be an issue. Often the employees setting this up have no knowledge of nor awareness of the impact on the surveillance system.
The best way to minimize obstructions is to:
- Train the people who watch the surveillance system to take note and make an issue of any obstructions.
- Have an integrator / service company conduct periodic maintenance.
Out of Focus Cameras
Another problem the FBI raises is cameras being out of focused as demonstrated in the screencap below:
This can happen from time to time. Two common steps are taken to mitigate this:
- Periodic maintenance - A technician will come on site every 3 to 6 months, check the focus and refocus each camera as needed. See our support / maintenance guide for recommendations.
- Auto back focus - A feature available on many new cameras allows for automatic re-focusing to eliminate this problem. Auto back focus (also called ABF) is increasingly popular. Even mid tier cameras now have this as a feature. Pay attention to cameras with ABF and prefer them if everything else is close.
The FBI says that webcams provide low quality video.
While that may be the reputation of webcams from many years ago, webcams actually offer excellent resolution at very low cost. For years, HD webcams under $100 have been commonplace. Indeed in our webcam test, they did surprisingly well with the biggest constraints being video processing and cable lengths. Webcams do not scale well but are actually a very economical choice for low budget applications just needing a camera or two.
The FBI notes the importance of resolution:
This example, though misleading, highlights the importance of both resolution and handling adverse lighting. For instance, the lower resolution shot on the right clearly suffers from a WDR / backlight issue. Sometimes, a scene needs more resolution but other times it is a lighting issue. Now, in 2012, the sweet spot for overall image quality is HD (720p or 1080p) from professional cameras. Lower resolution cameras, even with WDR, will not match. However, higher resolution cameras (3MP, 5MP, etc.) will almost always have major low light performance problems.
Depth of Field
The FBI advocates maximizing the depth of field and to this end they recommend lower F stops. The screencap below demonstrates the recommendation.
We disagree on this recommendation entirely:
- In photography, maximizing depth of fields requires higher F stops. This has a horrible side effect in surveillance - terrible low light images - as higher F stops restrict light input. As such, doing this is not practical.
- Depth of field even with low F stops is rarely a practical problem. The big issue typically is lack of resolution / image detail farther away from the camera but that is better handled through higher resolution rather than lens adjustments.
Width of FoV
The FBI cites the age old "15% rule" for capturing detailed facial shots of subjects:
This is well intentioned but it suffers from two major flaws:
- Too Tight: To meet the 15% rule, the total FoV width has to be 5-6 feet. This is way too tight to provide coverage of most facilities. By contrast, the average FoV width is closer to 15-20 feet. While this is often too wide to capture facial details, it is often necessary for cost effectively deploying systems.
- Megapixel Changes: Now with megapixel, you can have faces take up a much smaller percentage of a scene and still capture facial details. For instance, keeping the average 15-20 foot wide FoV and upgrading to 720p HD will likely deliver both a wide coverage area and facial details.
The FBI recommends over 20 cameras to cover the interior of a convenience store as shown by the yellow icons below:
The big challenge here is the cost. Typically, in a facility this size, we would expect to see about half the number of cameras the FBI recommends (8-10 in the interior). Doubling the number of cameras would be hard to justify.
As the FBI shows in the screencap below, the reason they recommend so many cameras is to have completely overlapping camera coverage with no dead spots:
While this is an ambitious and noble goal, the problem remains the cost. Almost no commercial facilities achieve this level of overlap due to it being cost prohibitive. Typically, half the number of cameras is 'good enough'.
The FBI points out again that lighting issues can cause problems identifying subjects as demonstrated in this screencap:
To handle that, they recommend installing artificial lights to offset sunlight. In the screencap below, the FBI demonstrates adding lighting to the left side of the scene:
This is simply a bad idea. Adding offsetting lighting works in photography shoots because a technician can adjust the lighting in real time to optimize the correct balance. However, in surveillance, this is not feasible. An offsetting light will sometimes make the scene better but other times worse because the level of the sun will vary throughout the day and because of weather conditions (clouds, rain, etc.). The FBI's earlier recommendation of WDR cameras is a much better solution to this problem.
The FBI recommends adding in shades to cut down glare on surveillance video.
This can be useful but keep in mind a few practical issues:
- These shades will also impact the overall ambiance and comfort of the business. Typically, this will be a net positive as usually people and cameras both dislike glare. Nonetheless, adding shades impacts the entire business and will need to be approved by owners / operational managers (outside of security).
- Even if shades are installed, shades will need to be raised or lowered on a daily basis. It is important that someone adjusts the shades regularly.
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The FBI offers a series of recommendations for sharing video with the authorities:
This is a complex and important topic. See our Guide to Sharing Surveillance Video with the Police for detailed recommendations.
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