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ISO

Rob Blatt — Tue, 10 Mar 2009 05:15:00 +0000

In still photography, the sensitivity of the silver halide crystals in the film to light. In digital still photography, the sensitivity of the image sensor to light. Digitally, it’s also known as the exposure index rating (EI).

Aperture

Rob Blatt — Wed, 18 Feb 2009 17:33:06 +0000

Aperture is a ratio of the focal length of a camera to the diameter of the iris of the camera. With a wider aperture, which is a lower number, more light will get into the camera. With a more narrow aperture, which is a higher number, the amount of time the camera is taking that image is going to need to be longer.

Sound

Rob Blatt — Thu, 05 Feb 2009 15:17:51 +0000

When something vibrates and creates a sound it changes the pressure of the medium that surrounds it, creating waves of varying pressure. The medium could be air, water, concrete, jello or just about anything with mass. The waves move through the medium and the compression/decompression is what is heard. The speed at which the medium vibrates is the frequency or tone of the sound and the amplitude is the amount of difference in air pressure, and it perceived as volume.