One of the three factors to control your exposure is your aperture. The aperture is the mechanical iris, consisting of a number of aperture blades, inside your camera lens that controls how much light it lets through to be exposed on your camera sensor. Similar to a camera lens, your eyes also have the capability to control the amount of light that enters your eye, which helps you to see in bright daylight, and in darker environments.
Depending on your camera (and lens), you can control your aperture by setting it electronically in your camera, or physically by rotating a ring on your lens. The latter is more common on older lenses and on retro-styled camera systems.
Reading your aperture
The aperture is indicated by the character ‘f’, followed by a forward slash ‘/’, and a number, for example f/2.8. In photography jargon, it is commonly referred to as f-number or f-stop. Something unconventional that you may need to get used to is that a lower number indicates that the lens lets through more light. A higher number indicates that the lens lets through less light. So, an aperture setting of f/2.8 lets through more light than f/11. For illustration purposes, we will indicate a large aperture with ‘f/2.8’ and a small aperture with ‘f/11’. Are you understanding it so far?
Aperture stops
In the past, when apertures were set mechanically.. even though some of the recent lens manufacturers also design their lenses with mechanical apertures.. each f-number was engraved in the lens. The difference between each number was generally one stop of light. This means that by switching from a large aperture to a smaller
As mentioned previously, the aperture can also be set electronically. This tends to be more applicable to digital cameras. In this case, the cameras allow you to fine-tune your aperture setting in half or third stop increments, which will help in obtaining more precise exposures.
Below you will find a short table of the most common full-stop apertures in photography.
f-numbers | |
---|---|
f/1 | |
f/1.4 | |
f/2 | |
f/2.8 | |
f/4 | |
f/5.6 | |
f/8 | |
f/11 | |
f/16 | |
f/22 | |
f/36 |
Kindly note that the above f-numbers are applicable to most consumer lenses. However, the f-numbers can even go beyond these numbers (both lower and higher numbers) depending on the lens.
How your aperture affects depth of field
Another concept related to aperture, is ‘depth of field’. In a nutshell, depth of field is the area of your photo that is in focus. This is a concept that we will cover in a future article, but we want to give you enough information that you at least can visualize it.
Everyone knows the classic situation of a great macro photo where the droplet of water sitting on the leaf is sharp and in focus, whereas other areas of the photo are blurry and out of focus. Remember that only the area that is still sharp belongs to your depth of field.
In general, photos taken with a larger aperture (f/2.8) allow for a shallower depth of field. This will help with isolating and putting more emphasis on the subject in your photo. On the other hand, photos taken with a smaller aperture (f/11) will have more of the photo sharp and in focus. A typical example for this is a landscape shot where you want to show the view on top of the very mountain that you just climbed. But depth of field is not solely affected by aperture. There are other factors that influence depth of field, but as mentioned before, this will be covered in a different article.
Limitations and considerations
Something that you may want to know in advance is that the maximum aperture, or the f-number that lets through the most amount light, is limited by the lens itself. Now, you may be thinking: “Then why are companies still making lenses with smaller maximum apertures?” or “Then I might as well just go for the lens with the largest maximum aperture.” We can understand your way of thinking, but, unfortunately, reality isn’t this simple.
See, even though the maximum aperture is lens-dependent, the construction of the lens and the lens elements required to achieve large maximum aperture lenses are incredibly complex. Companies invest a lot of money in research and development to create a product suitable for us consumers. And this money needs to be returned to the company. Who will end up paying for it? Of course, we as the consumer do.
Additionally, large maximum aperture lenses (f/2.8) are generally also larger in physical size. More lens elements, and more material for the housing of the lens, all increase the production cost of each unit. With that being said, the increase in number of lens elements and material also add up to the weight of the lens. Depending on your own situation and preferences, larger and heavier lenses are not particularly the best for traveling.. considering the maximum luggage allowance at airlines, or that 4-hour hike that you have been planning up the mountain.
Furthermore, companies will look at the performance and availability of similar products offered by themselves as well as their competition to determine the right price for their products. The more exclusive a product gets, the higher the price. A basic concept within economics.
Moving forward, now that the concept of aperture has been covered, let’s continue with the concept of ‘shutter speed’. And how shooting with a large aperture (f/2.8) will help in freezing that moment in time. Alternatively, you can proceed with ‘ISO’, if you would like to learn how you can use your image sensor to influence the way that you expose your photos.
P.S. In case you have not fully grasped the concept of aperture yet after reading this article, don’t worry. Read through (sections of) this article a few times to get a better hang of it.
1 thought on “Aperture”
Comments are closed.