RedLeaf Security - Low Lux Operation
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Low Lux Operation


Most cameras will work well in normal room lighting, but we have to take a careful look at the specifications to determine if the camera will work well at night or in bright sunlight. The ability of a camera to capture a picture based on the level of light is measured in lux. The lower the lux rating, the better the camera can see in low light. Light sensitivity is measured in LUX units. The LUX measures how much light is seen by the camera. The less light available, the more sensitive the camera has to be. Sensitivity ratings are generally given as the minimum "Lux" levels at which the camera will produce a useable image (1 Lux equals 1/10 Foot Candle). The lower the Lux number, the lower the light levels at which the camera will produce an acceptable image. In other words, the lower the Lux level rating, the more light sensitive the camera.

Network cameras operate in low light conditions by slowing down the lens and using an IR-cut filter or ICR. Slowing down the lens is like keeping the lens open on your still camera for a longer period of time. The result is clear images with precise colors even in low light. No worry while indoors or in dark situations. In addition, the superior lens and hardware design in Network video cameras enable them to capture high quality images even in the low-lux condition.

 

What affects the light sensitivity of a camera?

Lens f-number and type

A lens with a low f-number (such as f1.4) focuses much of the light from the scene onto the camera's sensitive Image sensor. In other words, a wide angle lens captures light from all over the scene. A close-up lens (or zoomed in lens) catches the light from only a small part of the scene. In very low light situations, the focal length of the lens (how far it is zoomed in) affects the camera's sensitivity.

Size and quality of the Image sensor

The quality of image sensor plays a very important role in its light sensitivity. The quality of the specific image sensor which is used in the camera determines the overall quality of the video output. The size of the image sensor is also important, an Image sensor has small squares or elements that are sensitive to light, so, the more light that falls on these elements, the stronger the signal.  The bigger the elements the more light can be collected in a specific length of time. 

Frame Rate and Shutter Speed

Reducing the camera’s shutter speed which also decreases the frame rate is another way of increasing camera’s sensitivity. This allows the light to fall on the Image sensor elements for a longer time. Normally cameras make 30 pictures per second. Thus they have 1/30 of a second to collect the light and convert it into a video signal. If the camera made 15 pictures per second, the image sensor would have 2 times as long to "look" at the picture and absorb the light.


RedLeaf uses high performance image sensors as well as advanced image processing techniques to produce high quality images even at low lux levels of 0.005 lux which is near total darkness.

 

 

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