If your camera has manual functionality then you will see some or all of these symbols on the dial. This is the dial on my camera, A/S/M are all one setting, you have to access the menu to choose which one you want.
Program Mode (P)
Shutter Priority (S or Tv)
In this mode you control the shutter speed and the camera will automatically set the aperture for the best exposure. Shutter speeds are measures of the length of time that light is allowed to strike the sensor of your digital camera, they are shown in fractions of a second e.g. 1/60 means that the shutter was open for 1/60 of a second. Shutter speeds affect the clarity and sharpness of your photos. This is not only with regard to camera shake, but to freeze motion, such as a child jumping high on a trampoline or splashes of water.
The faster the shutter speed the less blur, a fast shutter speed will need lots of light as less will be reaching the sensor. Sometimes you may want to deliberately set a slow shutter speed to allow moving parts of the scene to be blurred.
Use the sports mode on your cameras fixed shooting modes for a fast shutter speed, often depicted as a runner, but bear in mind you’ll need it to be a bright day to get good results.
Aperture is measured in f-stops, going from small numbers e.g F/2.0 where the aperture is open wide to larger numbers F/16.0 where the aperture is very small. Just like the pupil of your eye you can adjust the aperture to suit the light conditions, at night when light is low you have big pupils and in full sun you have tiny black dots. So if you are struggling for light set the aperture lower to allow more light in which increases the shutter speed, and reduces the chance of camera shake.
Importantly - the aperture also controls depth of field which means how much in front of and behind the point you are focussing on is acceptably sharp, which is so important to the final image.
For digital cameras with fixed shooting modes use portrait mode to get a wide aperture when you have less light and landscape mode to achieve small apertures. Portrait mode is usually a head and landscape is usually a mountain. Why those pictures you ask, well that all has to do with depth of field.
I will discuss depth of field on its own next week, I want to take some time to get some good pictures together to explain why it is important.
Questions or comments are most welcome!