BSL – Deep-Sky Imaging – How a camera works?

Cameras capture images by controlling how light enters through a lens and strikes a light-sensitive surface (either digital sensors or traditional photographic film).

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Lens & Apertures:
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Light reflects off a subject and passes through the camera lens.
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Inside the lens, an adjustable opening called the aperture acts like the pupil of an eye, expanding or contracting to control the total volume of light entering the camera.
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Shutter:
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Behind the aperture sits the shutter, a barrier that acts like an eyelid.
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When you press the shutter button, it opens for a set duration (shutter speed) -ranging from a fraction of a millisecond to several seconds (allowing light to reach the light-gathering element).

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Sensor / Film:
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In modern digital cameras, light hits an electronic image sensor (such as a CMOS or CCD chip) covered in millions of microscopic light sensors called pixels.
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These pixels convert the incoming light energy (photons) into electrical signals.

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Processing & Storage:
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An internal image processor converts these electrical signals into digital data (numbers representing colour and brightness levels) and writes the resulting file to a memory card.

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