As someone who is beginning to learn about photography, (beyond point and shoot of course) one of the things you are often reminded about is to be mindful of your camera’s aperture settings in order to become masterful in photography as Amatya Photography. Or if you are someone who is still learning about the controls of the DSLR you just got, aperture control is one of the settings you are curious to know more about.
Today, we will be learning more about the aperture, what it is about and why it is important to learn photography.
Of course, we have to first learn what aperture is all about. To make things simple, aperture is the hole within your camera lens through which light passes through. Think of aperture as something that works like our own eyes. In a way, cameras are designed like the human eyes actually.
Elaborating more on this analogy, the cornea in our eyes works like the front of our camera lens such that it gathers all external light and eventually passes it to the iris. The iris can either expand or shrink depending on how much light reaches the iris. In turn, the iris controls the size of the pupil, which is a hole that lets the light pass further into the eye. The pupil would be the equivalent of the aperture of the camera and this affects the retina which is the eye equivalent to the camera sensor. A larger pupil means more light can enter the retina. Same as well with the aperture in relation to the camera sensor.
Aperture Size and Values
As mentioned earlier, aperture is the value that controls how much light enters the camera. That value is expressed in f-numbers: f/1.4, f/4, f/5.6 and so on. These f-numbers that are known as “f-stops” are a way of describing the size of the aperture, or how open or closed the aperture is. A smaller f-stop means a larger aperture, while a larger f-stop means a smaller aperture. This can be confusing for many people since we are used to having larger numbers represent larger values. But when it comes to apertures, the opposite is the case. For example, f/1.4 is larger than f/2.0 and much larger than f/8.0, etc.
Aperture and Depth of Field
Now that we know the basics of aperture, it’s time to know more about how aperture affects photography with regards to the image output itself. One notable characteristic where aperture plays a significant part is with the depth of field of the image. Depth of field is the area of the image that appears sharp. With a large f-number such as f/32, (a smaller aperture as we have learned) it will bring all foreground and background objects in focus so everything in your photo is clear and well defined. On the other hand, a small f-number such as f/1.4 will isolate the foreground from the background by making the objects on the foreground look sharp while the elements in the background become blurry.
The Lens Factor
Every lens has a limit on how large or how small the aperture can get. If you check the specifications of your lens, it should say what the maximum (lowest f-number) and minimum (highest f-number) aperture values your lens offers. The most important thing to look at here would be the maximum because it shows the speed of the lens. For instance, a lens with a maximum aperture of f/1.2 or f/1.4 is considered to be a fast lens, because it can pass through more, making such lenses perfect for low light photography.
Another thing to note about lenses is the case aperture in zoom lenses, those lenses that let you zoom to capture images from a great deal of distance. Due to the complexity of optical design for zoom lenses, many zoom lenses have variable apertures. It means that the lens has different maximum aperture values depending on the zoom distance your lens is set to. For example, an 18-200mm lens has a variable maximum aperture of f/3.5-f/5.6, which means this lens, when zoomed fully out at 18mm, would have a maximum aperture of f/3.5. And when fully zoomed in at 200mm, the lens has a maximum aperture of f/5.6. Other professional zoom lenses would typically have fixed apertures instead, regardless of the zoom distance.
Remember that maximum aperture means that the lens can pass through more light, which will make your camera capture images faster in low-light situations. Having a larger maximum aperture also means better ability to isolate subjects from the background.