What is Aperture? What are the Effects on Photography?

In this article, we explained the aperture in photography. What is the aperture in the photo, how does it affect the photo, where and how is the aperture priority mode used? We will seek answers to questions.

What is Aperture in Photo?

aperture or aperture is a system that adjusts the amount of light falling on the sensor or film. While manual lenses are adjusted manually from the ring, today’s lenses are electronically controlled via the machine. The aperture is one of the basic elements of the photo formation process. The cameras do not have aperture. The aperture system is located on the lens.

As the origin of the word, Diaphragm (aperture) comes from a French word written as “diaphragme”.

In another case I want to mention at the beginning is that the aperture value is inversely proportional to the aperture value. For example, f1.4 aperture will have a higher aperture while f8 will be smaller. As the f value increases, the aperture diameter becomes smaller. Therefore, lenses with high f values ​​can pass less light. (What is the aperture: called the opening through which the light can pass through the leaves)
Because of today’s cameras, I will use the word sensor and not the word movie. The rays coming onto the sensor are first reflected from the object to be photographed. Then it passes through the lens of our machine. As it passes through the optical lenses and aperture ring, it falls on the sensor. And so the photograph is produced digitally.

Effects of Aperture on Photography

So how does aperture affect photography? In this process, the aperture has two important functions. The first is to adjust the amount of incoming light falling on the sensor. The second is to check the depth of field. Let’s examine these issues.

1. The effect of Aperture on light

From time to time, we observe that the photographs we take while using a lens such as 50mm f1.8 are very bright on very sunny days. The reason is that he took the photo with the clearest aperture f1.8. It’s very simple we have to do. To narrow the aperture of our lens. So to raise it to a value like f5.6. Sometimes, contrary to the situation above, if our photo turns out to be too dark, the solution should be to open the aperture, that is, to change the aperture value to a smaller value of 2.8.

We said aperture, a complete system. It consists of aperture baldes, a ring and a powertrain. But in photography, the aperture value that we will take more photos from the system is important. Because it is one of the most important values ​​that directly affect photography. So what is the Aperture value?

Aperture Value in Photo:

Simply aperture value; It is the value obtained by dividing the focal length of the lens by the aperture diameter. I will not consider it theoretically. How it is calculated is not our topic at the moment. I will try to study the effect on the photo. Take f2.8, for example. All lenses with a 2.8 aperture are expected to take pictures with the same brightness at the same values ​​under the same lighting conditions. How so?

The photograph taken by a 35mm f2.8 lens and a 300mm f2.8 lens under the same lighting conditions should be the same in the light (except for frame difference). So someone should not be darker or brighter. 35mm lenses are 3 cm long and 300mm lenses are at least 20 cm long. So how will the light pass from 3cm to 20cm at the same rate? Here is an engineering-appreciated subject and its answer is hidden in aperture values.

Aperture – Light calculation

The aperture value is indicated by f. In photography, f values ​​are fixed and are as follows with ORDER. They are listed as 1 – 1.4 -2 – 2.8 – 4 – 5.6 – 8 – 11 – 16 – 22 – 32 – 45 – 64 – 91 .. However, in addition to these values ​​in cameras or lenses, half (1/2) or 1/3 stop values ​​are written. For example, between f2.8 and f4, there is a half stop value of f3.5. While explaining the subject, we will talk more about the exact stops. These aperture values ​​mean: The next stop dims the light exactly twice. (If you have a shutter speed of 2.8 aperture at 1/60 sec while taking pictures in the same light, f4 will be halved and will be 1/30).

Diaphragm systems are mostly located on the lenses. The smallest value that a lens can give you and the smallest value is written on the lenses. For fixed focus prime lenses, the maximum aperture should be written in the part where the lens name is written. Like the knitting’s f1.4 on Nikon 50mm f1.4. This will mean the following. The maximum aperture of this lens can be f1.4. But the shortest aperture value may not write in the same place. But he definitely writes about the aperture rights of the lenses. For example, the minimum hoarseness in the lens above was f16. We can see it from the aperture chart.

Another thing to note here is that a lens does not have all apertures. In other words, if f1 and f64 can be in the same lens, I think that lens will be 1 ton or something. And it will be worth a fortune. Manufacturers often produce consecutive 8-10 full stop aperture lenses as they want to avoid both cumbersome and cost.

If our lens is a variable focus lens rather than a fixed focus, the f value; As shown, it is represented by two numbers. This means that. For example; In a 18-105mm f3.5-5.6 lens, it can get a maximum of 3.5 aperture at 18mm, but at 105mm, it can take a maximum of 5.6 aperture. In other words, 105 mm, which is the largest focal length, will not get the 3.5 value. It can take the f values ​​starting from F5.6. But some zoom lenses don’t like it. For example, a 24-105mm f4 lens means it can always get f4 at any focal value. These types of fixed aperture lenses are higher quality and more expensive than other zoom lenses.

A Rightly Known Wrong: ‘Mathematics Doesn’t Lie’

I want to open a parenthesis here again. You will be a little confused. You cannot get out of the work you are looking at, ignore this paragraph. In fact, aperture values ​​are always expressed as 1 / at the beginning of the value, as in f1 / 1.8. What have we said so far: “As the aperture value decreases, the aperture width increases”. In fact, it’s not mathematically correct. We express it in this way because it has become widespread in this way among the public.

In fact, it’s mathematically the opposite. In other words, mathematically f 1 / 2.8 value is greater than f 1/4 value and the aperture increases as the value increases. But this is the case mathematically. Since we are used to talking the opposite way among the people, we talk about the aperture value increases as the f value decreases. Since I finished the explanation in this paragraph from the Mathematics Department, I wanted to write it simply because I knew how to borrow it. I’m sorry if I’m confused.

What is Pre-set Aperture

Some lenses, besides the full-stop aperture, are the 2nd with no stops, sliding aperture that slide like oil as you turn them. Such sets of apertures are called preset apertures. They are apertures used for those who shoot video rather than photography. Pictures can be taken up to the preset aperture value. Old Soviet lenses are famous in the manuals.

One of the most famous is the 135mm f2.8 lens called Zenit Tair 11-A. It is a lens with very nice optic quality and unique bokeh. Anyway, our subject is the aperture of this lens; Let’s go back there. One of the two aperture rings rotates with a snap while the other rotates without a stop. In other words, it can stop without a stop in between. It also has the function of locking the other of the stop aperture (preset). If the pause aperture of the sample stops at f8, the other preset aperture only works between f2.8 and 8. Takes pictures at f8 in auto mode. The stop diaphragm will be locked. Modern lenses today are actually preset apertures.

Yes, let’s move on to the other function of the aperture:

2. Effect of Aperture on Depth of Field:

Net Depth of Field It is called the places that are not seen in the photo and seen clearly. Clear depth of field in a photograph; It depends on 4 main factors. These factors are the subject of my writing here. For us, the most important of these factors is the aperture for now. The effect of the aperture on the net depth of field occurs as follows. The larger the aperture value, the shorter the aperture, the clear depth of field will increase (the fuzzy area will decrease, the net areas will increase); the clearer the aperture, that is, the smaller the value, the lower the depth of the field will decrease (the fuzzy area will increase, the net areas will decrease)

Depth of Field in Portrait Photography and Landscape Photography

Portrait photographers want the background to be as blurry as possible so that the portrait can be in the foreground. Therefore, they can achieve the desired rear (or front) blur with an light aperture. For example, 50mm f1.4 or 85mm f1.8 are among the classic portrait lenses.

Landscape photographers also want every area in their frame to be clear. They use short-focus lenses and high apertures for this. For example, 16mm f11 are the values ​​of a classic landscape photograph. They often use 16-35mm f2.8 or 16-35mm f4 lenses. The main reason for using f2.8 in such lenses is not the depth of field, but to take clear pictures in low light conditions. As a result, the 16-35mm F2.8 lens can also be dimmed down to f11; The 16-35mm f4 lens can also be dimmed down to f11.

Since macro photographers approach their objects as close as possible, the depth of field decreases to be measured in millimeters. They use the lowest values ​​of their lenses to increase depth of field. Depth of field increases but light transmittance decreases. Therefore, they try to capture the ideal photo by removing this deficiency with snaps and ISO.With these examples, let me finish the effect of the aperture on the net depth of field. Finally, there are a few notes I would like to add.

Things to Know About Aperture in Photography:

** The ideal photo is not taken just by changing the aperture or shutter speeds. After finding the appropriate frame, the result will be achieved by correctly adjusting the aperture, shutter speed and ISO values.

** Avoid using the lightest aperture value of your lenses if you don’t need or give special effects. The vast majority of lenses are not able to give the clearest-sharpest image in their lightest apertures. You can shoot 1-2 full stops for the sharpest image

** The shapes of the background bokeh are related to the shapes of the aperture baldes. Lens manufacturers increase the number of aperture baldes to give more circular bokeh. For example, the tair 11-a I mentioned above uses 15 aperture blades and can give full circular bokeh. At the same time, the lens named industar is star-shaped, and some versions of the Hellios 53 lens produce very different bokeh thanks to square-shaped aperture baldes.

Using Aperture Priority Mode

** If you cannot shoot the camera in full manual mode, the most useful mode is “aperture priority” mode. This mode is shown with A in many brands such as Nikon-Sony, while Canon is shown with Av. In this shooting mode, you set the aperture value from the camera or lens; your machine will automatically give the shutter value according to the ambient light.

** It is inherent to use open aperture in portrait shots and aperture in landscape photographs.

** When you change the aperture values ​​of your lens, keep in mind that other variables also reach different values. For example, in a situation where you sometimes need to shorten the aperture, your shutter speed will decrease considerably for the ideal photo. Therefore, your photos will come out shakyly, that is, without being clear. For the ideal photo, you should find your aperture value by instantly connecting it with the shutter speed and ISO value. Otherwise, you can take off the eyes when you say I would make an eyebrow.

You can see the details of ISO from the magnificent trio of photography by clicking here for shutter speed.

May your light be of good quality.