This video is part of our intro to photography series, where we break some fundamental concepts of the process of making image. You can find a written version below.
Introduction to exposure
What is aperture?
The aperture value is one of the fundamental aspects of the exposure and perhaps the most intimidating, but it is not needed. The easiest way to think about it is the name of the hole through which your camera sees the world. A large hole gives more light, and a small hole gives in low.
Why are that sequence aperture numbers?
| First, the aperture scale can be difficult to understand, as it becomes 1.4, 2, 2.8, 4, 5.6, 8, etc. |
The naming system may seem misleading at the first time: aperture settings are nominated for which fraction of focal length, the diameter of the hole. This risk is confusing in two ways: first, a small number represents a large hole, and, secondly, belongs to the square root of pattern 2. Most people will not be able to think spontaneously in the context of Route 2, so your best bets will be to remember them.
How does aperture affect exposure?
The important thing to learn is that changing your aperture value in a complete form ‘doubling or half light, in the same way that your shutter speed is doubled or half. Over time, you will remember that F2 is a complete stop bright compared to F2.8 and this F4 another stop is less bright.
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| F2 | F2.8 |
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| F4 |
This is why very large aperture lenses are generally much larger and more expensive than lenses that are not bright.
Along with going to more light, to give you better image quality in low light condition, a wide aperture will also give you shallow depth-field and staining background. But this is a story for another day.
