Question: Does the "rolling shutter" aspect of cameras impact measurements?

jenjimah asked on April 12, 2019 18:53
125 | 0 answers | #19046


According to Pi documentation, a rolling shutter means that the camera reads the sensor one line at a time. This is a quality of most, if not all, cameras without a physical shutter.

For lights that flicker, e.g. fluorescent lights and LEDs that use pulse width modulation (PWM) for dimming, this can result in "banding" where the intensity varies as the camera reads down the sensor lines.

So aspects of the question are:

  • How noticeable is banding when measuring flickering lights?
  • Is banding reduced by using longer shutter speeds?
  • Can this be balanced without overflowing the sensor at "normal" light intensities used in research?
  • What kinds of measurements might this be a problem for, which types of measurements is it irrelevant for?
  • If it's a problem, what are some solutions?


2 Comments

Possible examples of banding:

128155 - fluorescent bulb banding1.JPG

122557 - CFL banding2.JPG

97106 - Calibration banding3.JPG

91584 - looks like a white LED banding4.JPG

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154520 banding5.JPG

153053 - sunlight banding6.JPG Since this example is sunlight, this may mean some distortions are attributable to factors other than the rolling shutter effect.

banding6.JPG

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