Merry Christmas…

December 23, 2010 at 10:04 am | Posted in FS8 Security System | 2 Comments

Frame rate

December 17, 2010 at 7:27 am | Posted in Articles | Leave a comment

1 frame per second is the lowest frame rate recordable and 30 frames per second is the maximum which is real time.

There is no real need to record in real time unless there are regulatory reasons as in case of government facilities or casinos.

At 3 – 5 frames per second recording you will not miss any activity (remember this is per second).

You can always rewind in high speed so the lower the frame rate the faster it is to playback an entire day.

Distance VS Lens

December 12, 2010 at 10:33 am | Posted in Articles | Leave a comment

The table below shows the area the camera will cover on the screen

Real Examples

Each of these images were captured from 10 metres from the car. Note how the DETAIL and AREA covered by the camera changes depending on the lens size.

Camera 10m away using a 3.6mm lens

Camera 10m away using a 6mm lens

Camera 10m away using a 8mm lens

Camera 10m away using a 12mm lens

Fixed Focal Lens VS Varivocal Lens

December 12, 2010 at 10:15 am | Posted in Articles | Leave a comment

One of the most common lenses in use today, the fixed focal length lens is relatively economical. However, it offers only one focal length, usually between f/1.3 to f/1.8, which cannot be changed. Because the optics in this type of camera is simple and to-the-point in nature, these lenses are usually considered faster than variable- focal-length models. Fixed focal length lenses come in standard, wide-angle, telephoto and variable zoom.

Camera lenses can be divided into two basic types: fixed focal and varifocal (or zoom). A fixed focal lens has a constant focal length, while a varifocal lens can change its focal length. Focal length is simply the distance from the optical center of the lens to a focal point near the back of the lens. This distance is written on the lens (in millimeters) and indicates the field of view produced by the lens

*Focal length Figure*

Fixed focal length lenses are available in various wide, medium, and narrow fields of view. A lens with a “normal” focal length (Ex: 8.0mm on a 1/3″ camera) produces a picture that approximates the field of view produced by the human eye. A wide-angle lens has a short focal length, while a telephoto lens has a long focal length (See figure 8). When you select a fixed lens for a particular field of view, bear in mind that if you want to change the field of view, you must change the lens.

Shorter focal length = wide angle               Longer focal length = telephoto

*Wide angle vs telephoto Figure*

When both wide scenes and close-up views are needed, a varifocal or zoom lens is best. A zoom lens is an assembly of lens elements that move to change the focal length from a wide angle to telephoto while maintaining focus on the camera’s imager. This permits you to change the field of view between narrow, medium, and wide angles, all on one lens.

When deciding on what lens you need, consider:

  • – What DISTANCE will the camera be placed from the object(s) to be viewed?
  • – How much AREA do you want to view on screen around the object(s) to be viewed?
  • – How much DETAIL do you want to capture?

A lens that will give you a wider viewing angle, such as a 4mm lens, will offer you very little in terms of detail. However a 12mm or 25mm lens, which will give you great detail, will not cover a large area since the field of view is narrowed.

What If I Do Not Know Exactly How Far I Need To See?

Instead of going with a fixed focus lens you can go with a varifocal lens. With a simple adjustment you can manually zoom in or zoom out and focus the camera to the exact distance needed to get a clear picture. Varifocal lenses come in all different sizes: (3.5-8mm; 9-22mm; and 5-50mm) just to name a few. This is the best option for large commercial applications because you can adjust the focal distance to what works just right.

Which Security Camera Lens Should I Use?

How far you need to see will determine what security camera lens you should use to best fit your application. A 4mm lens will give a 70 degree angle of view with 35 feet of facial detail. This works great for residential or small office security camera applications. If you need to see further you would go with a higher powered lens. Keep in mind that the further you want to see will narrow the field of view of your picture.

What is Auto-Iris Control used for?

December 12, 2010 at 9:45 am | Posted in Articles | 2 Comments

A lens with Auto-Iris Control has a motorized iris that adjusts automatically to only allow a specific amount of light to pass to the imaging sensor / CCD sensor. If the lighting conditions are very bright the lens will close the iris to reduce the amount of light that is passing to the imaging sensor. Same is true if there is very low light, the lens will open to allow more light to pass to the imaging senor making the image appear brighter. The major benefit to the Auto-Iris lens is that they will adjust to any lighting conditions. This can be very useful in a situation where a camera is installed outside of a building, the camera as the light changes during the day will change the iris to help maintain the picture quality.

Auto iris lens are options on most cameras. Most box / long body style cameras accept either Manual or Auto-Iris style lens. The lens does require power so make sure the the camera that you are selecting has the option for an Auto-Iris lens.

What is Back Light Compensation/BLC used for?

December 12, 2010 at 9:36 am | Posted in Articles | Leave a comment

Many cameras that are sold in today’s CCTV market include a Back Light Compensation ( BLC ) setting. This setting is used to help correct times when the lighting behind a object that you are trying to view is much brighter then the object itself. A good example of this is an entryway camera. The light from the outside shines through the glass and is much brighter then the light that is inside the store. As the person walks into the store they light that is cast on the is much darker the the light that is outside. This causes the camera to produce a very dark image with very little detail of the subject being viewed. By using BLC the brightness of the outside light will be reduced to allow the subject to appear brighter and create a better detailed image of the subject. For another solution for entry way cameras look in to cameras that have a wide dynamic range ( WDR ).

Without BLC                                 With BLC

What is Automatic Gain Control / AGC used for?

December 12, 2010 at 9:19 am | Posted in Articles | Leave a comment

Automatic Gain Control (AGC) is an automatic adjustment that security camera will make when the lighting conditions change. If the light level is low the AGC will increase the signal strength.  AGC does have pre-set limits to keep the gain from going too high or low, this keeps the output video at a consistent level. Some cameras allow you to change the gain level on the camera if you need to adjust the limits.

Most cameras on the market come with built in Automatic Gain Control (AGC). This feature measures the brightness of the picture and will adjust to keep the video signal at a consistent level. If the picture became very bright for example the AGC would decrease the gain to bring the brightness level down to a normal level

How Much Power do my Cameras Require?

December 11, 2010 at 12:40 pm | Posted in Articles | Leave a comment

Most of the cameras require a 12V DC power supply although some have dual voltage 12/24V adapters built in and some cameras require 230V AC power.

The voltage of the camera you need will vary depending on the installation but most of our customers use 12V DC cameras due to the fact that high voltage 230V cameras require a qualified electrician to provide a link to the mains. It is very important that you do not supply a higher voltage than the camera is rated for as this will blow the board and the camera will be useless.

This information should also be available in any accompanying paperwork in the camera box. Unlike voltage, you can supply the ampage in excess of what the camera needs as it will only take what it needs. When specifying your installation be sure to make note of what cameras you are installing, what voltage they need to be and how many there are so that you can choose an appropriate power supply .

Power supplys are needed whenever you are using a 12V or 24V camera to transform the 230V from the mains to the appropriate voltage. The PSU’s are available as individual plug in units up to 1 Amp (1000mA) suitable for single cameras and as metal boxed power supplys up to 4 Amp suitable for powering multiple cameras.

E.g. – An installation with 8 internal colour 12V dome cameras each comsuming 200mA would require the power supply to be able to provide 200mA to each of the 8 cameras. Therefore you would need at least 1.6Amp (1600mA) to power all the cameras. In this case you could use a 12V 2Amp metal boxed power supply unit

What is the difference between CCD and CMOS image sensors in a digital camera?

December 11, 2010 at 12:13 pm | Posted in Articles | Leave a comment

Digital cameras have become extremely common as the prices have come down. One of the drivers behind the falling prices has been the introduction of CMOS image sensors. CMOS sensors are much less expensive to manufacture than CCD sensors.

Both CCD (charge-coupled device) and CMOS (complimentary metal-oxide semiconductor) image sensors start at the same point — they have to convert light into electrons. If you have read the article How Solar Cells Work, you understand one technology that is used to perform the conversion. One simplified way to think about the sensor used in a digital camera (or camcorder) is to think of it as having a 2-D array of thousands or millions of tiny solar cells, each of which transforms the light from one small portion of the image into electrons. Both CCD and CMOS devices perform this task using a variety of technologies.

The next step is to read the value (accumulated charge) of each cell in the image. In a CCD device, the charge is actually transported across the chip and read at one corner of the array. An analog-to-digital converter turns each pixel’s value into a digital value. In most CMOS devices, there are several transistors at each pixel that amplify and move the charge using more traditional wires. The CMOS approach is more flexible because each pixel can be read individually.

CCDs use a special manufacturing process to create the ability to transport charge across the chip without distortion. This process leads to very high-quality sensors in terms of fidelity and light sensitivity. CMOS chips, on the other hand, use traditional manufacturing processes to create the chip — the same processes used to make most microprocessors. Because of the manufacturing differences, there have been some noticeable differences between CCD and CMOS sensors.

  • CCD sensors, as mentioned above, create high-quality, low-noise images. CMOS sensors, traditionally, are more susceptible to noise.
  • Because each pixel on a CMOS sensor has several transistors located next to it, the light sensitivity of a CMOS chip tends to be lower. Many of the photons hitting the chip hit the transistors instead of the photodiode.
  • CMOS traditionally consumes little power. Implementing a sensor in CMOS yields a low-power sensor.
  • CCDs use a process that consumes lots of power. CCDs consume as much as 100 times more power than an equivalent CMOS sensor.
  • CMOS chips can be fabricated on just about any standard silicon production line, so they tend to be extremely inexpensive compared to CCD sensors.
  • CCD sensors have been mass produced for a longer period of time, so they are more mature. They tend to have higher quality and more pixels.

Based on these differences, you can see that CCDs tend to be used in cameras that focus on high-quality images with lots of pixels and excellent light sensitivity. CMOS sensors traditionally have lower quality, lower resolution and lower sensitivity. CMOS sensors are just now improving to the point where they reach near parity with CCD devices in some applications. CMOS cameras are usually less expensive and have great battery life.

Indoor Camouflage Camera6

December 5, 2010 at 5:20 pm | Posted in Indoor Camera | Leave a comment

Mini Sharp CCD Camera(FS8-930PD) -> Rp 800.000

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