Why bother with different sized apertures or shutter speeds?
Because you can alter the effect that is achieved. For example, if you are taking a photograph of a landscape then you might want to select a narrow aperture, such as f11, because the narrower the aperture is, the larger will be the area in front of and behind your subject which is in focus (larger depth of field or DOF). On the other hand, if you are taking a photograph of your kids, you might prefer the area behind them to be blurred in order to make your kids stand out from their surroundings. For that you could choose a wider aperture, such as f2.8, because the wider the aperture is, the smaller will be the DOF. On the other hand, sometimes it’s worthwhile selecting a slow shutter speed – for example if you have got a waterfall right in front of you and want to convey movement by blurring the water. For that you could deliberately choose a slower speed, e.g. 1/10sec, because the slower the shutter speed the more likely the camera is to record any movement as blur rather than keepin
