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Dead Pixel: a pixel that reads zero or is always off on all exposures. This state produces a black pixel in the final image.
Stuck Pixel: a pixel that always reads high or is always on at maximum intensity on all exposures. This produces a white pixel in the final image.
Hot Pixel: a pixel that reads high on long exposures and can produce white, shades of red/orange or green pixels. These pixels become more evident with longer exposures.
Testing for Dead or Stuck pixels
The best way to test for Dead or Stuck pixels is to use a pure white and a pure red card. Take a picture of each card under normal lighting conditions.
If the pixel is dead it will show up on the picture of the white card as a black pixel.
If the pixel is stuck, it will show up as a white pixel on the picture of the black card
A common mistake in testing for Dead or Stuck pixels is to cover the lens with the lens cap, set the camera to a slow ISO speed such as 80 and taking a long exposure.
This produces some red, greenish and sometimes white pixels.This is a normal state and it is referred to as Christmas Tree artifacting.
The color is caused by the RGB and CMY colored filters of the CCD. In addition, a dead pixel is dead all the time and would not show up with this test since the pixel is black.
Stuck Pixel: a pixel that always reads high or is always on at maximum intensity on all exposures. This produces a white pixel in the final image.
Hot Pixel: a pixel that reads high on long exposures and can produce white, shades of red/orange or green pixels. These pixels become more evident with longer exposures.
Testing for Dead or Stuck pixels
The best way to test for Dead or Stuck pixels is to use a pure white and a pure red card. Take a picture of each card under normal lighting conditions.
If the pixel is dead it will show up on the picture of the white card as a black pixel.
If the pixel is stuck, it will show up as a white pixel on the picture of the black card
A common mistake in testing for Dead or Stuck pixels is to cover the lens with the lens cap, set the camera to a slow ISO speed such as 80 and taking a long exposure.
This produces some red, greenish and sometimes white pixels.This is a normal state and it is referred to as Christmas Tree artifacting.
The color is caused by the RGB and CMY colored filters of the CCD. In addition, a dead pixel is dead all the time and would not show up with this test since the pixel is black.
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