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A DSLR camera is still the first choice and best
camera for photographing the crime scenes and physical evidence.
However not all police agencies can afford to buy a DSLR camera kit.
If that is the case then we offer the following as secondary to the
DSLR. We are going to look at the factors that should be considered in
selecting a "simple" digital camera for police use. You may ask why
not simply buy a digital SLR style camera? There may be several
reasons. First and foremost, SLRs are still among the more
expensive cameras on the market and not all agencies can afford the
investment. Second, they are more camera than needed for many
common police uses- things like minor accidents, assaults and field
ID pictures. Thirdly they can be confusing to operate for those
with limited training.
Even for agencies who have digital SLR style cameras available,
point-and-shoot cameras can be a good investment. In my opinion, in
an ideal world every officer would have a camera in their shirt
pocket to use as necessary. The best camera for many jobs is simply
the one you have ready at hand, not the one back in your trunk or
locked in a cabinet at the station.
We can't recommend specific camera models simply because they change
every three to six months, so by the time you read this any camera
we recommend will probably have been replaced with a newer model.
With that in mind, let's look at camera features.
Resolution. Resolution is measured in mega-pixels. Six or more
mega-pixels should be more than sufficient for most uses. The main
exception is comparison photographs of shoeprints. Most
point-and-shoot cameras are not suitable for shoeprint work. Those
that are, feature eight or more mega-pixels and the ability to work
with a detachable flash unit. These features are more easily found
in SLR style cameras, for which ICSIA has a separate spec sheet.
However there are a few Point and Shot or "Bridge Cameras" that come
close to this capabilty.
Exposure. The ability to alter exposure from "automatic" settings
is required. This is referred to as exposure compensation or
exposure value (E.V.) adjustment. On many cameras this is not
available in the green "idiot proof" auto exposure, but is available
in Program exposure. This allows you to lighten or darken a picture
if the built in meter is fooled.
Flash. A suitable camera will have a built in flash, and the
ability to control the output power of the flash unit. This is
referred to as flash exposure compensation.
Lens/Zoom range. This is often listed several ways as a "zoom
factor" (i.e. 3x or 12x zoom range), as a "digital zoom" factor and
in 35mm camera equivalent (35-400mm equivalent). The important
factors are to disregard the digital zoom factor as this simply
degrades your image. In fact, on those cameras that have this
feature we recommend switching it off. The zoom factor is less
important than the lens equivalent. A large zoom range is not
necessary for police use. The factor to look at is the wide angle
lens equivalent, which is the smaller of the numbers listed. A
35-400mm lens has 35mm as it's widest available setting. A 28-105mm
lens has 28mm as it's widest setting. You are more likely to have
use for a wide setting than for a telephoto setting. 35mm lens
equivalents are relatively common, wider lenses are not, but can be
useful- particularly for overall shots of building interiors.
Macro/close focus capability. A suitable camera will have the
ability to focus to approx. 1 inch or less. This is necessary for
close-up photographs of injuries or damaged objects.
ISO. ISO is the "film speed" available on the camera. The higher
the number, the less light is required to take a picture but the
noisier or grainier the image appears. A suitable camera will have
a maximum ISO of at least 400 and the ability to manually control
ISO settings. It is important to carefully read a review of the
specific camera you are considering as some cameras can shoot at 400
ISO with little or no noise and others produce images that look
horrible at this setting.
Batteries. There are cameras available with AA batteries and some
with rechargeable batteries. There are advantages to both. AA
batteries are easily available, and can be picked up almost
everywhere in an emergency. AA alkaline batteries will not last
long in a digital camera however. Lithium batteries will provide
more life, but are expensive. NiMH rechargeable batteries also work
well, but be sure to buy a spare set. Cameras which take
Lithium-Ion rechargeable batteries will provide better battery life
than those which take AA, but make sure to purchase a second battery
that will fit your camera so that you can keep shooting while
charging the other battery.
Memory card type. There is no particular advantage to one memory
card type over another. However, most cameras ship with memory
cards which are too small for serious use. Invest in at least two
cards for each camera with a size of 1 gigabyte or larger. If you
have multiple cameras it's nice to have them all use the same memory
card type.
Shake or Vibration Reduction. This feature compensates for camera
shake caused by the inability to hold the camera perfectly still
without a tripod. It is very effective at reducing blurred images
due to shaky hands. It is not absolutely necessary, but is a nice
feature to have if available.
Weather Proofing. Some cameras are available with seals to keep out
moisture if you use them in the rain. This is a nice feature to
have but is not absolutely necessary.
Conclusion/Guidelines. A suitable point and shoot style camera will
have:
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Six or more mega-pixels.
Exposure compensation.
A built in flash with adjustable power.
A 35mm or wider equivalent lens.
Ability to focus to one inch or less.
At least 400 ISO available and manual ISO control.
Extra batteries and extra memory cards. |
The camera should be "adjustable". The camera
should have the capability to be used both in automatic or program
mode and be able to make adjustments to correct the exposure or
increase the depth of field.
Both shake reduction and weather proofing are desirable features,
but are not necessarily required.
Two good websites for camera reviews are:
http://www.dpreview.com and
http://www.dcresource.com
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