There are various ways in which you can manually determine the characteristics of a photograph. Of these ways, the shutter speed is a key one; being the length of time a camera’s shutter is open when taking a photograph with the amount of exposure determining the amount of light that reaches the film or image sensor. A fast shutter speed (1/4000th of a second) will capture a sharp image of a fast subject (under good lighting conditions). A slow shutter speed (from 1/4th of a second and less) will open the shutter for so long that any movement during the duration of the exposure will be blurred and in daylight, so much light will come in that it will look almost-white. If you do a long exposure in the dark you can paint with light (as we have done here below on the left) keeping the shutter open for 30 seconds and moving a torch around to paint streaks. The opposite image is taken with the shutter open for 1000/th of a second, freezing the fast water splashing the subject.
Another way of affecting the look of the image is the aperture. The aperture refers to the opening of a lens’s diaphragm through which light passes. It is calibrated in f/stops and is generally written as numbers such as 1.4, 2, 2.8, 4, 5.6, 8, 11 and 16. The lower f/stops give more exposure because they represent the larger apertures, while the higher f/stops give less exposure because they represent smaller apertures. The aperture primarily affects the depth of field. The higher the f/stop the greater the depth of field is (as can be seen below on the left; everything is in focus). If you do the opposite you get a blurry background with the subject sharp (badly shown with the image on the right…not the best example, but it does vaguely represent a shallow depth of field).
The final adjustment you can make is the ISO. When you change your ISO setting, you’re adjusting your camera’s sensitivity to light. ISO settings can be anywhere from 24 to 6,400 (or higher), and these numbers have a direct relationship with the device’s sensitivity, so a lower setting makes it less sensitive and a high setting makes it more so. The two images below demonstrate an ISO setting of 200 and 1600 (allowing too much light and burning out the image). With daylight (outdoors) you want a much lower ISO.