Welcome to my post ” Lens Aperture explained for Beginners “. In this post I will try to explain the lens aperture in more technical yet simpler details.
What is Lens Aperture?
Lens aperture basically, in the simplest terms, is a hole in which light can pass through. That hole can vary in size. The size or diameter of the lens aperture, or the hole determines the amount of light that will pass through. Obviously, the larger the hole, more light will pass through, and smaller the hole, less light will pass through. Therefore, a photographer can control the brightness( and a few other things– explained later) of the photo by selecting the size of the aperture.
How is Lens Aperture Selected
On photographic lenses, the aperture is marked as a sequence of numbers. These numbers look like (1.4 , 1.8, 2, 2.8, 4, 5.6 . and so on). These numbers refer to the diameter of the hole. Smaller number means wide opening, and larger numbers mean narrow opening. That simple. Photographer refer to these numbers stops or f/stops. So if I select an aperture of 2.8, I would say I’m at f/2.8. On modern lenses, aperture is selected electronically on the camera body- yehhh modern technology! Camera in auto mode can automatically select the right aperture based on the lighting conditions of your scene. This process of selecting aperture is also automatic in your point and shoot cameras, smart phones, tablets or any other mobile device that has a camera built into it.
So what do these apertures numbers mean?
These numbers as mentioned earlier control the diameter of the aperture. Aperture value of 1.8 will result in a wide opening compared with an aperture value of 5.6 will result in a narrow opening. Aperture values such as are fraction of 1. Therefore if your do the simple math, 1 divided 1.8 (f/1.8) will yield approximately 0.55. And 1 divided by 5.6(f/5.6) will yield 0.18. You see 0.55 is larger than 0.18. Figure below illustrates the f/stops
Depth of Field.
Lens Aperture not only controls the amount of light that passes through the lens. It also controls what is known as depth of field. Depth of field is the area around the focus point.
High f-numbers will produce sharp depth of field. More area behind and in front of the focus point will be in focus. Low f-numbers produce shallow depth of field. More area around the focus point will be out of focus. Photographer call this the ‘bokeh’ effect or creamy effect. Shallow dept of field with low f/stop makes the subject stand out and blurs the background.
Sharp depth of field (Nikon USA)
Shallow depth of field(Nikon USA)
How do I determine what aperture value to select?
Photography is careful mixture of three common camera setting. These setting are, aperture, sensor sensitivity(ISO), and shutter speed. Mastering these three essential components can result in stunning photography. There are some guidelines for selecting all three based on lighting conditions and whether your subject is moving or stationary. Photography is just as experimental as it is theory. So get your DSLR out and take some beautiful Autumn shots. More articles coming on other essential components of the camera.