(Photo credit: Evin Grant)

Did you ever wonder what creates permanently lit, or what we often refer to as “blown”, pixels in your CCD camera’s imager? Here’s the reason:

Charged-Coupled Devices (CCD’s) are made up of an array of millions of photodiodes, which turn light into voltage. Photodiodes have two leads coming from the bottom, a cathode and an anode. When a photon of energy strikes the diode, it excites an electron, creating a mobile electron and a positively charged electron hole. Holes move toward the anode, and electrons toward the cathode, producing a photocurrent. Because photodiodes use voltage to convey information, they can be susceptible to high-energy particles such as cosmic rays.

…continue reading Lit Pixels: Why Do They Happen?

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Time-lapse refers to a shot that follows a transition in time, like an entire sunset in a matter of seconds, or the flowering of a plant in under a minute. It’s accomplished by taking a few frames over the course of a longer interval, and when shown at a faster frame rate, creates the illusion that the event happened in a much shorter time. It’s different from stop-motion photography, where the frame is manually exposed just once, and then time is taken to change the scene. Here, the interval of time between exposures can vary greatly. With time-lapse photography, the interval remains the same.

…continue reading Time-Lapse Recording