Aperture
Overview:
Last time we talked about the shutter speed on your camera. I want to focus on aperture this week.
Aperture
Did you know that the human eye works like the aperture on a camera lens? If you were in a dark cave, your pupils would get bigger to try and let more light in. When you are outside on a sunny day, your pupils get smaller because of the amount of light coming in. Aperture is referred to the lens diaphragm opening inside a photographic lens. The size of the diaphragm opening in a camera lens REGULATES amount of light passes through onto the film inside the camera the moment when the shutter curtain in camera opens during an exposure process. The size of an aperture in a lens can either be a fixed or the most popular form in an adjustable type (like an SLR camera). Aperture size is usually calibrated in f-numbers or f-stops. i.e. those little numbers engraved on the lens barrel like f22 (f/22),f16 (f/16), f/11, f/8.0, f/5.6, f/4.0, f/2.8, f/2.0, f/1.8 etc.
Aperture affects the image in two ways. The first is the relationship to shutter speed. The smaller the aperture (large number), the longer the shutter speed needs to be. This can create blur in a photo. The best use of this is when trying to make a stream look like lace (small aperture, long shutter speed). If you would like to stop motion then use a large aperture (small number) and a faster shutter speed.
The second way aperture affects the photo is the depth of field – the area of a photo which appears in focus. A small aperture (like f/16) has a very large depth of field. The foreground and background will appear in focus. This is helpful for landscape photographs. A large aperture (like f/2.8) will have a shallow depth of field. This allows the subject to be separated visually from the out of focus background or foreground.
The images below shows how a small aperture works, (what is in focus?):
If you look at what is in focus on this photo, you see that the leaves and the dew drops are in focus when the background in not in focus.
Taking a look at Buster, his head is in focus when the rest of his body is not.
What is Aperture?
Lets put this as simple as possible– Aperture is ‘the size of the opening in the lens when a picture is taken, this helps regulate the amount of light let onto the sensor.