There are various types of exposures eg: long exposure, fast exposure, etc which refers to a single shutter cycle to allow certain amount of light to pass through lens and to the sensor.
Here are couple of examples how exposures is used in various circumstances:
Shutter SpeedShutter speed is the length of time the camera's shutter is open when photographing a subject. In other words, shutter speed is responsible for freezing an action or blurring the motion.
If we consider the above two pictures as an example, the image 1 has the action freezed and the image 2 has a motion blurred.
Before photographing any subject you need to know what should be the shutter speed?
When you need to photograph a sharp looking moving object you need to have higher shutter speed about 600 to 1000. When photographing a motion less or still object you need to set the shutter speed to 60, make sure not to shake your camera if you are shouting hand held or better use a tripod. You can use 60 to 125 shutter speed while photographing portrait and landscapes. Also make sure there is good amount light on the subject.
|Aperture size from larger to smaller rate|
Smaller aperture: Larger f-number like f/16 to f/32 is required when you need the subject and the foreground and the background of the subject to be sharp thus when the depth of field is increased. Use small aperture while photographing landscapes and architecture. You need to also think about the amount of light available to set the aperture. For indoor photography since there will not be enough light, you need to reduce the f-number to 5.6 (The max value in some of the kit lenses) to allow more light to pass into your camera. When you set smaller aperture when there is not enough light the picture will become darker you may need to use flash light in those conditions.
Larger aperture: Smaller f-number like f/3 to f/2.8 is useful when you need the foreground and the background of a subject to be blurred therefore the depth of field id reduced. While photographing portraits you can set the larger aperture so that the background of the subject is out of focus and the subject only will be sharp. Larger aperture is also useful in macro photography as it lets more light to pass into the camera and helps the camera's sensor to capture the subject much sharper.
ISOISO is the level of sensitivity of your camera's sensor to the available light. Increasing the ISO value will add more noise and grains to your image. ISO is an important aspect of digital photography to have an understanding of if you want to gain more control of your digital camera. When you are shooting outdoor in a bright light always use lower ISO 100 to 300 this will reduce the noise fully. Even when you are doing wildlife photography make sure to set the ISO as low as possible to produce a better quality picture.
Increase the ISO value only when you really need to shoot is low light situations though it adds more noise to your picture it allows your sensor to capture the subject you need.
Finally now you can take your camera out and shoot with manual mode to practically set and understand how Shutter Speed + Aperture + ISO helps each other in producing a better picture.
Points to remember:
- Always photograph by mounting you camera to a tripod when you have set lower shutter speed
- Do not increase the ISO more than 400
- Use flash in low light conditions so that you could still use lower ISO value
- Use Smaller aperture to photograph landscape
- Use Larger aperture for portraits and macro
- Review the pictures on computer for better understanding on how the various values of shutter speed, aperture and ISO works.