Low light camera modules from e-con Systems: Cooling the CCD from room temperature to -25C will reduce dark current by more. Responsivity is synonymous with sensitivity, and also indicates the efficiency of an imager in converting photons from a low light scene into detailed images. When calculating overall SNR, all noise sources need to be taken into. Cameras with high sensitivity allow efficient conversion of low light images to quality outputs, making it an inevitable feature for low light cameras. Sensitivity is an indicator of the ability of an image sensor to convert incident photon energy to electrical signals. Depth of field is a crucial consideration for an application with varying working distances, and hence a careful design is required while building a low light imaging system for such applications. However, increasing the lens aperture reduces the depth-of-field of a camera. Some sensors include the measurement of dark. To capture images in low light conditions, a larger lens aperture is recommended allowing more photons to reach the sensor. The dark current can be measured by capturing images at various exposure times with the sensor closed by its cap. This is a design consideration than a specification of an imaging system. Lens aperture determines the quantity of light that falls on the sensor. A low-light camera comes with the ability to minimize these noise components to achieve a higher SNR thereby producing good quality images. In an imaging sensor, dark current and transistor noise are some of the major noise components. SNR or Signal to Noise Ratio, in simple terms refers to the ratio of the quantity of signal (valid image data) to the noise (invalid image data) in an image. However, it is to be noted that with increased pixel size, only fewer pixels can be accommodated in a compact imaging sensor causing either a reduction in resolution or an increase in the sensor size. This makes pixel size one of the most critical factors considered while choosing a camera for low light applications. The bigger the well, higher the number of photons collected, and hence better would be the performance of the camera in a low light environment. Pixel size in sensors that come with low light performance is typically 3µm or larger. Pixels are square wells that collect photons, and pixel size refers to the dimension of this square well. Pixel size is the physical dimension of a single pixel in an image sensor. Since this fit is used later to calculate the dark count, independent from the neighboring pixels, the actual. Traditional techniques to measure the dark current were designed for CCD cameras and do not take into account the specific.

consumer cameras, a cooling system is not feasible and dark current can. To decrease the generation of dark current, many camera systems are cooled. Let us now look at each of the above factors in detail. Dark current is a major source of noise in digital imagers. Noise Study In this section, we build a model for the noise level func-tions of CCD cameras. The factors that contribute to the low light performance of a camera are:

Camera calculate dark noise