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Top 10 tips to avoid camera placement problems

For want of a nail, the battle was lost, goes the old proverb. Businesses are sinking big bucks into video surveillance systems — all for nought in many cases because their cameras aren’t placed correctly to capture decent images.


June 6, 2008
By Rosie Lombardi

“I would say about half of the cameras installed for identification
purposes aren’t installed properly, and 20 per cent for general
surveillance. Discussions about high-end features are empty unless the
cameras are first installed correctly,” says John Day, president of
Toronto-based Contact North Representatives, which is the Canadian
manufacturing agent for Bosch Security Systems. Day’s role is to
investigate video surveillance systems malfunctions on-site and to
provide training to Bosch’s customers and dealers.

Placement issues can be expensive to fix, says George Majkut, senior
director of loss prevention at The Source by Circuit City, an
electronics retailer and Contact North customer. Camera panning and
placement problems were creating blind spots in image capture, he says.
“We had to buy new cameras after an incident. When we went back to
review the videos, we’d lost the event.”

Day says there are plenty of horror stories of video evidence lost due
to incorrectly placed cameras. In one instance, a security director at
a high-tech firm was fired a week after a video system was installed,
as it didn’t capture identifiable shots of thieves entering and exiting
the building with a ring of laptop bags strung across their shoulders –
one of which was her boss’. “That one sticks in my throat,” says Day.
“She wasn’t responsible beyond trusting the company that installed the
system.”

To avoid camera placement snafus, experts recommend the following tips:


Basic rules of thumb for identification shots

Installations for identification purposes are more challenging than
general surveillance, says Day. “But if companies obey these three
rules, they should be in good shape.”

•    A person’s head must fill at least 20 per cent of the screen height of the original image
•    Lighting needs to be controlled in the area the camera is viewing
•    The angle of view should be kept shallow


Dilemma: View in or out?


Should cameras be pointed in or out at entrances? Companies face a
dilemma, as there are disadvantages in both scenarios. If they’re
pointed outwards, natural light streaming in from outside may blur
images. But if they’re pointed inwards, the camera mostly captures
people’s backs. Experts have divergent views on the issue.

Cameras should be pointed inwards to capture people’s faces as they
leave, says John Sandeman, commander of the video services unit at the
Toronto police. Rationale: Criminals are typically aware of cameras
when they enter, and wear caps or otherwise obscure their faces to
avoid identification. But adrenaline surges after a crime is committed,
and they have an instinctive need to look up to check the cameras as
they exit towards freedom. “We just need that one frame to identify
them.”

But Day prefers to point them outwards so faces are captured as people
enter. Rationale: Most buildings have more exit than entry points. If
people aren’t identified at entrances, they may elude identification
altogether by leaving via a fire escape. “Then you’ve got nothing. So
you must fight that or fight backlighting. I’d rather fight the
backlight, even if it means moving cameras further inside or using two
cameras in the reception area.”


Angle of view

The commonest problem is cameras placed on wide-angle views in lobbies,
parking lots and other large areas, says Sandeman, “Companies trying to
cover as much area as possible in an image turn out to be covering
little except a lot of walls.”

A related issue is that cameras are often mounted on ceilings, which
means they’re angled downwards at people and may not capture facial
features, says Day. Moreover, about a third of the frame is wasted on
irrelevant ceiling shots, and images may also be blurred by fluorescent
lighting. “They should be mounted on the wall so people’s heads fill 20
percent of the screen and backlighting is avoided.”



Cameras at choke-points

To cover large dark areas such as parking lots, cameras are best placed
in strategic areas such as stairwells, entrances and exits instead of
placing many wide-angle cameras throughout the lot. Lack of sufficient
light and wide-angles means these cameras won’t capture identifying
information. “I see example after example of this. Putting them in
well-lit stairwells where they can get clear face shots is more useful
than placing them all over the place. At the Toronto police, we
emphasize camera placement at choke-points.” Day agrees, but warns
there’s no video evidence if criminals arrive or leave by car.
Higher-end technology such as mega-pixel cameras and video analytics
technology may be solutions in high-risk areas to capture facial shots
or spot unusual behaviour patterns, such as people walking in zig-zag
pattern towards cars.


Check the back-focus

A fairly common problem with less-challenging general surveillance
cameras is that they’re often installed without the right adjustments
to back-focus settings, says Day. “Images taken during the day look
alright, but they look fuzzy at night.” How well a camera can focus
depends on the aperture, which opens to maximum settings at night.
“That’s when it’s hardest for the camera to focus.” Cameras typically
have adjustments to position imagers, and there may be subtle
variations from lens to lens. “Most come from the factory perfectly
back-focused, but I wouldn’t rely on that.”


Ask about results

Security managers must have a clear idea of their risk areas and what
results they’re expecting from their video surveillance systems before
they’re installed. Often, they’re dazzled by the technology and not
focused on concrete results, which allows vendors to avoid making
commitments about how the technology performs in key risk scenarios,
says Day. “If car break-ins are a big risk, end-users should ask the
vendor, ‘What is your system going to give me?’ They can use that as
the criteria to evaluate the installation.”


Dealing with installers

Companies must do their due diligence in checking a security company’s
credentials and references, says Day. Even so, the actual installation
is often handled by another contractor, who may not have the right
expertise. “The person installing the camera must understand the
purpose of the camera, otherwise, there’s no hope it will be placed
correctly. But it’s rare for companies to talk to installers before
they’re actually on-site.”

Companies should check if the security company does both the design and
installation of the system, he says. “If they don’t do both, end-users
should find out if the security company will take responsibility for
the results of the system so they know who to go to if they’re
unhappy.” Designers often provide clear specifications to their
installers, which should be sufficient to protect customers – if
companies are prepared to enforce them. “But rarely do I see companies
check to see if what they received is what they were promised.”


Do a Walk-test

Security managers should always request a walk-test with installers to
go through a series of actions that simulate the greatest risk areas
and playing back the images to see exactly what video systems capture,
says Day. If the system is meant to identify license plate numbers, for
example, a test should be conducted for that risk. “This is a
fundamental thing but about 90 per cent of the systems I encounter
haven’t been walk-tested. People are only aware of what they’re getting
after an incident occurs, so the success of the system depends on them
somehow anticipating all problems.”



Get feedback from front-line staff

Security managers don’t always talk to frontline staff who actually
work in the areas cameras are in, says Majkut. “I don’t know everything
that’s going on so I must rely on my team to help me make informed
decisions.” Reports from staff prompted him to review and replace
cameras in The Source’s entranceway. “Our staff said an event occurred,
but when we went back to check the video, the images either weren’t
there or were blurry.”  


Police can still investigate if cameras fail

While good, clear images can be very useful in investigating cases,
Sandeman emphasizes they aren’t central in making a case. “Bad camera
placement may cause problems, but we can still pursue a case without
fantastic images. There’s no question identifying images are helpful.
But back in the seventies, we were nevertheless able to convict people
without video. People tend to forget that.”