Dark current
Stray electrical charge that appears in areas of the CCD elements that are not exposed to light. The result is irregular noise in image areas such as shadows.
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Dark current
Techniques Glossary Dark current
Stray electrical charge that appears in areas of the CCD elements that are not exposed to light. The result is irregular noise in image areas such as shadows.
Dark Current Noise
A few paragraphs above, it was mentioned that pixels measure light by counting photons. This is a simplified view.
Dark Current
Dark Noise
The charge accumulated by pixels while not exposed to light. Normally, this charge is reduced or eliminated prior to capturing a picture.
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Dark Current
Pixels collect signal-charges in the absence of light over time, which can vary from pixel to pixel. The result is known as dark current, or more commonly as noise.
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Dark Current
a.k.a. noise, dark noise. Pixels collect signal-charges in the absence of light over time, which can vary from pixel to pixel, and the result is known as dark current.
Also called dark current, this is the voltage from a CCD when no light is incident on the CCD.
definition:
The clarity of detail in an image; dependent upon resolution (number of pixels) and contrast.
Thermal noise, dark current, and cosmic rays may alter the pixels in the CCD array. To counter such effects, astronomers take an average of several exposures with the CCD shutter closed and opened.
Dark Current The electronic signal generated by the thermal characteristics of the CCD even in the absence of impinging light.
I used to work in digital image processing (I actually processed Hubble Space Telescope images before it got its "glasses", right after it went into orbit) about 10 years ago, and we did lots of tests of what we called "dark currents".
For a digital camera to know what black is, it needs to take a dark current reading, which is the base value of a completely black pixel.
Photon shot noise dominates at high signal levels (short exposure) and comes from the basic statistics of photon detection. Thermal shot noise comes from the dark current of a sensor and is strongly correlated with temperature (lower temperature ...
(due to read-out and other circuitry on the chip), then higher pixel densities will result in less light gathering area unless the microlenses can compensate for this loss. Additionally, this ignores the impact of fixed pattern or dark current noise, ...
 See also: Camera, Image, Digital, Noise, Pixel
  
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