What is Aperture?
YASIR WAQAR
Network Engineer | Branding, Graphics, Cybersecurity, Ethical Hacker | I help SMEs drive an 80% Increase in traffic and test network security
What Is Aperture?
In photography, an aperture is the opening of a lens used to control the amount of light necessary to expose the sensor/film; in addition, the aperture is used creatively to control the compositional use of depth of field. A smaller (closed) aperture restricts light and increases the depth of field in a scene, whereas a larger (open) aperture allows for more light and decreases the depth of field within a scene.
But, why does this matter to you? By understanding aperture, I can help you capture images that better achieve your creative vision. This article is designed to be the ultimate guide to understanding aperture and comes from our full-length course Photography 101. However, I want to be clear, this article, along with the education on SLR Lounge, are not designed to be technical manuals, but rather field guides.
If you haven’t already, be sure to check out our official guides to ISO and Shutter Speed, which are of course the other two parts of the Exposure Triangle.
We create real-world field guides designed to get you out and shooting as quickly as possible. For those who are interested, we will include additional technical details and facts at the end of the article. Let’s dive into the first piece of this article, which is using the aperture to control your image exposure.
APERTURE FOR EXPOSURE CONTROL
Aperture is one of the three pillars within the exposure triangle, shown below.
In our introduction, we simplified the exposure component of Aperture to the following: larger (open) apertures allow more light to reach the sensor/film, while smaller (closed) apertures allow less. The pupil of your eye works in the same way! Your pupils naturally close to restrict light in bright environments and open (dilate) to allow for more light in dark conditions. Hold on to this simple truth as we discuss the details of Aperture.
First, let’s talk about how Aperture is measured and depicted. When we discussed ISOand Shutter Speed, number increments were naturally intuitive. A higher ISO speed represents higher sensor/film sensitivity, and thus more light, but also with the downside of decreased image detail. A higher Shutter Speed represents the shutter opening and closing faster, to freeze motion and also reduce the time for light to expose the sensor.
click below for more detail...