DSLR Terminology(Apertur,Shutterspeed, ISO Overview)

The aperture is basically the opening of the lens, and it's what light passes through before it hits the image sensor or film plane. The aperture is a metal leaf diaphragm, and it's contained inside the lens, and we can open and close this diaphragm by adjusting our aperture setting on our camera.

Now some cameras control the aperture within the camera body by using a rotating dial, while on some models you'll find an aperture ring at the base of the lens. The aperture size is usually communicated in terms of f numbers or an f-stop. The larger the number, the smaller the lens opening, and the smaller the number, the wider the lens opening.

So for example, this lens I have here is an f/2.8, right now the lens is wide open, it's allowing the maximum amount of light through the lens. If I rotate this aperture ring down to f/22, I'm in a sense closing the aperture, making it much smaller. Now, not only does this affect the amount of light that passes through the lens, this also controls your depth of field. The smaller the aperture, say f/22, the greater depth of field we have, meaning more of the image is going to be sharp, or in focus. The larger the aperture, or the wider it's opened, we're going to have a shallower depth of field, which would give us a reduced area of sharpness. Now the camera's shutter is located within the camera body. And the shutter basically controls the amount of time in which the image sensor gets exposed to the light that's coming through the lens. The speed at which the shutter moves is known as the camera's shutter speed, and depending upon your make and model, the shutter speed can range anywhere from 30 seconds up to 8 thousandths of a second, or even higher on some professional DSLR cameras.

Changing your shutter speed is quite simple, simply locate the dial on you camera body and rotate it to the left or to the right, which will increase or decrease the camera's shutter speed. Now you've probably noticed you have an ISO setting on your camera.

The ISO is describing how sensitive your camera currently is to light. The ISO is completely adjustable, and can range anywhere between 80 and 6400, depending upon your camera's make and model. ISO is a term from the film photography days, and it stands for International Standard Organization, and this was put in place to describe the sensitivity of films.

So for example, if you had a 100 ISO rated film, it was considered to be best used in bright light conditions, while if you had a 3200 speed rated ISO film, it was considered to be fast because it would take less light to burn on to the film, making it perfect to use in low light conditions. And the same holds true for the image sensor in your camera, higher ISO settings are great for shooting in low light, while lower ISO settings are better for shooting when you have a lot of light. Shooting at a slow ISO also gives you a more natural saturated color and less grain, while a higher ISO can render a more grainy image, which is often referred to as camera noise. It's quite easy to change the ISO settings on any DSLR camera.!