A camera system consists of cameras with the proper lenses, in an
enclosure (if necessary), with video storage and the software to glue it
all together. To specify the right system first answer the following
questions:
- How large an area do you want to view? The distance away and how wide an
area you would like to view will help determine the type of lens you need. The
higher the “mmthe smaller the field of view and the more magnification you
get.
For example a 4 mm lens provides a viewing angle of about 60 degrees of
viewing angle, and a 40 mm lens provides a viewing angle of about 7 degrees. The
40mm lens provides about 9X magnification.
- Do you need a pan, tilt, zoom type camera system or can you use a high
resolution wide angle camera system that provides digital pan, tilt and zoom?
If you have a horizontal viewing angle of less than 120 degrees you may be
able to use the IQeye camera. This
camera has a very high resolution. For example the IQ301 has a 1.8 M pixel
imager which allows you to achieve 16X digital zoom and still read a license
plate number.
The digital PTZ is better because it allows you to
store full images and never miss anything. The mechanical PTZ camera could have
been looking in the wrong direction when the interesting event occurred.
The mechanical PTZ has an advantage if you need to pan over 120 degrees
and view things clearly at 20X.
-
Do you want to view things at night? Do you have
lights on, and how bright are they? This information will help determine how
sensitive the camera should be.
Low cost cameras have a minimum light sensitivity of about 3 lux, while
better cameras provide better than 1 lux sensitivity. 1 lux is about the light
you get from a full moon.
- Do you want to use the camera outside? If the camera needs to be used in a
wide variety of lighting conditions, you need an auto-iris lens that adjusts to
the light.
Some low cost cameras such as the Axis205 and Axis2100 do not
have the capability to use an auto-iris lens and so are better suited for indoor
operation.
- How much detail do you want to see? Do you want to be able to zoom in on a
persons face and be able to identify the person, or just want to see that
someone was there? This helps determine the resolution of the camera or the
zoom you will need.
- For how long a period do you want to store the video for days, weeks, or
months? This determines how much video storage you will need.
Special video software runs on your PC and is used to control and store
the video from IP type cameras. It lets you view many cameras on one window,
store the video, provides alarms when motion is detected, controls PTZ cameras,
and much more.
Examples of software available include SoftSite32,
NetDVR-64, Axis Camera Explorer and Axis Camera Station.
- Motion detection helps reduce the storage requirements. Can you estimate
what percentage of the time you expect to see motion?
The IP software allows you to select certain areas of the view that are
sensitive to motion.
Once motion is detected you can be notified by email,
sound alarm or even receive a page.
- The frame rate also determines how much storage you will require. For
example you can select a frame rate from less than 1 fps to 30 fps. A higher
frame rate allows you to see fast motion, but you can sometimes get away with
frame rates of about 1 frame/sec.
- What are the weather conditions in your area (winter & summer
temperatures)? This will determine what type of environmental enclosure you
will need.
- How many cameras do you need? This will allow us to calculate how much video
storage you will need.
- Would you like to view the cameras remotely over the Internet? This will
determine what type of IP software we recommend.
NetDVR-allows users to view the
cameras from a remote location using a standard web browser. It is
licensed for 4, 9 16, 32 and 64 cameras. There is no difference in price
for different types of cameras. This is sometimes a less expensive
solution.
HIGH-end Video Server Module board W1860
