Last week we talked about one of three main characteristics of the photography – ISO. Today we will explore another pillar each photo is based on – aperture.
Aperture is the most creative tool out of three you can play with due to its ability to add dimension by blurring background or bringing everything in focus.
Aperture is the hole in lens through which the light travels to camera sensor. This hole can either dilate or contract by using a mechanism built in the lens. The more its dilated, the more light comes in, the bigger the aperture.
The design of it was taken from the human eye which works exactly the same way. If you ever paid attention to somebody’s eye once you turn off the light in a room you would see how the pupil expands in order to gather more light and try to see through the dimmed environment. Same goes with aperture. So if you shooting night time or in a bad lighting condition, you would need higher aperture so the camera could “see” the picture.
The aperture is measured in F-numbers of F-stops. The smaller the F-stop the bigger the aperture and vice versa. It might seem confusing at first and hard to remember but once you get your hands on the camera and play with aperture settings you will get a hang of it right away and see that for example, f/1.4 is larger than f/2.0 and much larger than f/8.0.
Taken from Wikipedia
The depth of field is the most fun thing you can get out of changing your aperture. It is the area of the image that appears to be sharp. A large f-number such as f/32, (smaller aperture) will bring all foreground and background objects in focus, while a small f-number such as f/1.4 will isolate the foreground from the background by making the foreground objects sharp and the background blurry.
Taken from Exposure Guide
As you can seen the picture above, the difference between changing aperture from f/2 to f/16 is drastic and the background with the bigger aperture (f/2) gets really blurry.
Ever heard when photographers start bragging about how fast their lens is? The term “fast” applies to the maximum aperture the lens can offer which is usually f/1.8 or f/2.5. Lens with these f numbers are considered to fast lens because it can pass through the most amount of light to the camera. Usually the fast lens is the choice of landscape photographers because in a dim lighting conditions like shooting the night sky it requires to get as much light as possible without bumping up the ISO and introducing distortion. Every lens has a limit on how large or how small the aperture can get. If you take a look at the specifications of your lens, it should say what the maximum (lowest f-number) and minimum apertures (highest f-number) of your lens are.
The minimum aperture is not that important, because almost all modern lenses can provide at least f/16 as the minimum aperture, which is typically more than enough for everyday photography needs.
Next time when you purchase or rent a lens, take a look at what aperture it can provide. Usually the lens that has the best aperture are “fixed” or “prime” lens. Fixed lens cannot zoom in and out so you would need to physically need to move the camera closer to the object in order to get a closer look. The zoom lenses on the other hand have a lower maximum aperture (usually) and also change the f/number to a bigger one (smaller aperture) once you zoom in depending on how the lens was built. The more expensive lens ($1000 up) might have a set aperture regardless of your focal length.
Check out this great blog post on exposure by photographytalk.com called The Exposure Triangle Explained in Plain English
For more information and awesome animated instructions take a look at this video made by Apalapse
