Before we answer this question, it's important to understand the basic principles of aperture and how it works. If you’re already familiar with aperture, skip to Aperture on the L16, below.
Aperture on an SLR camera
In traditional photography, each lens has a series of adjustable metal blades that narrow or widen to let certain amounts of light pass through. Aperture controls the size of that opening, and, in turn, the amount of light that hits the camera’s sensor. The larger the opening, the more light allowed in; the smaller the opening, the less light allowed in.
Aperture also affects depth of field—or the range of your image that will be in focus. The human eye is a good comparison, as it functions similarly to a camera’s lens and aperture. If you try focusing your eyes on an object nearby, you’ll notice that the other parts around it—which are the same distance away from you—are also in focus. When you try focusing on something far behind your first object, you’ll notice how the first object is no longer in focus—and neither are the other equidistant objects.
Aperture works the same way. When your camera is focused on a subject, it will create an imaginary plane of focus. The area in front and behind that focal point that is in focus is the depth of field. Depth of field grows deeper or shallower depending on the aperture. When the aperture is large, like f/1.8, there’s not as much range of focus in front of and behind the focal point. In other words, the depth of field is shallow, and objects outside of the plane of focus will appear blurry. Shallow depth of field is often used to draw attention to or isolate the subject from the rest of its environment. A smaller aperture like f/22 creates a deeper depth of field, so the areas in front of and behind the focal point are all in focus.
Landscape photographers tend to shoot at smaller apertures (i.e. f/16, smaller opening) in an effort to keep more of their image in focus, whereas sports photographers shoot with larger apertures (f/2, bigger opening) to focus solely on the point of action and blur the surrounding areas. Additionally, the more light they allow into their cameras, the faster they can set their shutter speed to stop the motion of the sport.
Aperture on the L16
There is no native aperture control on the L16 because it doesn’t function like an SLR. Since the L16 is shooting with 10+ camera modules at a time, there’s no need to adjust aperture on each of the modules—it’s just automatically set to be wide open. For the 28mm and 70mm lenses that means f/2.0 and for the 150mm lenses, f/2.4.
Why do we do this? For starters, our lenses are nearly diffraction limited, which means they are as good as physics will allow them to be. If we reduced the aperture of our lenses, it would reduce the resolution of the lens. And secondly, the more light we can capture, the more information we have about the scene. By keeping each lens wide open, the L16 can gather more data about the scene in front of you. And the more information the L16 has, the higher the quality of images it can generate.
The beauty of computational imaging is the ability to control depth of field after an image has been taken—so you don’t have to worry about setting the aperture while you’re out in the field. You can decide whether the photo should have a deep or shallow depth of field—and you can even try out different depths of the same photo. That way, aperture is one less thing to worry about, and depth of field is one more creative option you have to make your images look exactly the way you want them.