What is written on the lens?
Please look at this lens - what do the numbers on the lens barrel mean?
Aperture of a lens is the aperture value of a lens when it is fully open.
For the lens in the photo just above, the lens aperture is 2.6. And than less number, topics lens aperture more. Paradox?
There is no paradox here ... when we say MAXIMUM DIAPHRAGM, it means that it is completely open and we mean the size of the aperture hole, and not its designation with a number. And the number indicating the aperture at its maximum opening will be minimal because in reality it is the denominator of a natural fraction (if you notice, 1: 2.8 is written on the lens barrel - these two points are a mathematical division mark, often there is so little space on the frame, that the division sign and the unit are simply not written
Why is lens aperture important when choosing a camera?
When choosing a camera with a removable (=interchangeable) lens, you can buy a fast lens and replace the one you already have. But if you are going to buy a camera with a fixed lens (for example, a compact camera), it is very important to find a suitable camera model with a fast lens - with an aperture of no worse than 2.8. Because the more the lens aperture opens, the more freedom you will have, the freer you will feel in non-standard lighting conditions.
In addition, the depth of field depends on the aperture of the lens. In turn, depends on your photos.
Many compact cameras have a very limited choice of apertures, and as a result, a large depth of field. Moreover, some super-compact models of digital cameras and almost all cameras do not have smartphones and phones - in such cameras, instead of the classic diaphragm (an adjustable hole in the baffle between the lens lenses), a special filter is used, the transparency of which is regulated by the camera electronics. With such a camera, it is generally impossible to influence the depth of field. I'm not going to say it's good or bad. It all depends on
If you don't want to "bother" with the camera settings and you like to just point the camera at the subject and press the shutter button - you won't even notice the difference. If you like to experiment a lot, shooting in different, often not ideal, lighting conditions, 2 or 3 apertures available can severely limit your options.
When choosing a lens for their digital camera, photographers often face the fact that with the same focal length or range of focal lengths (if we are talking about zoom lenses), optics can have different aperture ratios. At the same time, sellers often advise purchasing more expensive optics, referring precisely to the high aperture ratio, as if it is able to solve all problems when shooting. But is this really so, and what fast lenses can the market of photographic equipment offer us today?
Advantages and disadvantages of fast optics
Aperture is understood as the bandwidth of the lens, that is, the maximum possible amount of light that will pass through the optics and hit the camera matrix. Accordingly, the higher the lens aperture, the more light will pass through it. What does it give in practice?
First, in different lighting conditions, when shooting handheld or photographing moving subjects, you can use a faster shutter speed. Secondly, fast optics allow you to shoot at lower ISO speeds, thereby minimizing the amount of digital noise. Thirdly, fast lenses provide faster autofocus, which is especially important, for example, in reportage photography. Fourthly, a wide maximum aperture allows the photographer to limit the depth of field of the imaged space. Fifth, thanks to the fast aperture, which provides a bright image in the viewfinder, the photographer can control the sharpness and composition of the picture with confidence. Finally, when photographing at apertures close to maximum, you can get a nice, beautifully blurred background.
Thus, the advantages of high-aperture optics are sufficient. But there are also disadvantages. First of all, these are more serious overall dimensions, since a large maximum aperture requires the use of lenses of a larger diameter and additional optical elements designed to help eliminate chromatic aberrations and distortions. As a result, the design of a high-aperture lens in comparison with non-aperture optics at the same focal length becomes more complicated.
Fast lenses with internal focusing are slightly shorter. In this case, during the focusing process, small optical elements move inside the lens, while the front elements, which have more serious dimensions, remain stationary. With internal focusing of the lens, there is virtually no rotation of the front element of the optics. Plus, the speed of autofocus increases, and the balance of the design of a fast lens, in general, improves.
The second disadvantage of fast optics is closely intertwined with the first. Since the design of such lenses uses larger optical elements, it is much more difficult for specialists to manufacture and correct such optics. As a result, the cost of optics increases. The high price is, perhaps, the main disadvantage of high-aperture optics from the point of view of any photography enthusiast or enthusiastic photographer.
On the other hand, as a rule, fast lenses are created using the most modern technical solutions and the highest quality materials, which means that by paying a more serious price for optics, the photographer gets something more than just a higher aperture. When used correctly, a fast lens can provide a significant improvement in image quality, which is especially important for professional photographers in particular.
Choice of fast optics
It should be noted that the very concept of high aperture, in general, is rather relative. For example, the difference in lenses with a maximum aperture of f / 1.2, 1.4 or 1.8 in practice is often difficult to feel. By the way, it is known that one of the fastest lenses was developed in the mid-60s for the NASA space program in order to photograph the dark side of the moon with its help. It was a CarlZeissPlanar 50mm with f/0.7 aperture.
Beginners often chase after the lens with the highest aperture and, of course, sellers are happy to sell them such optics, because it costs many times more. But is it worth paying extra for an f/1.4 or f/1.2 lens if you don't shoot at maximum aperture very often? This is the first question you should ask yourself when choosing fast optics. Today in the market of photographic equipment you can find a fairly wide range of fast lenses - both optics with a fixed focal length and zoom lenses. Several interesting models can be distinguished.
Sigma 30 mmf/1.4 EXDCHSM
This fast f/1.4 lens is designed for cropped SLR cameras with APS-C sensor format. It has a rugged body, a 45-degree field of view and a traditional optical design consisting of seven elements in seven groups. The design uses two optical elements made of low dispersion glass (Special Low Dispersion), which ensures the elimination of chromatic aberrations.
The Sigma 30mm f/1.4 EX DC HSM is equipped with an eight-blade diaphragm and an ultrasonic motor (HSM) for faster and near-silent focusing. The advantages of this lens include good color reproduction and a pleasant, unusual pattern. At the same time, it requires precise adjustment of the focus in the camera and is characterized by a drop in sharpness in the corners of the frame.
A fast lens with a focal length of 50 mm, taking into account the crop factor, it can be used in various shooting situations - in portrait, landscape or genre photography. The Sigma 50mm f/1.4 EX DG HSM has a circular nine-bladed aperture that can beautifully blur out-of-focus areas. The optical design includes eight elements in six groups, including a molded aspherical lens, which effectively suppresses chromatic aberration.
The likelihood of glare is minimized due to the use of multilayer coating of optical elements. It also contributes to higher contrast in photographic images. The minimum focusing distance is only 45 cm. The equipment of the optics also includes an ultrasonic HSM autofocus drive. It is noteworthy that the fast lens Sigma 50mm f/1.4 EX DG HSM can be used with both digital SLRs and film cameras.
Canon's lineup includes the EF 50mm f/1.4 USM prime lens with a standard 46-degree field of view and ultrasonic focus motor (USM) with continuous manual focus adjustment. This lens is versatile in use and compact in size. The optics design, consisting of seven elements in six groups, uses elements with high light refraction, which provides the ability to create sharp, detailed images even at full aperture. An 8-blade, nearly circular aperture diaphragm creates even, smooth blur for out-of-focus areas of the image. The Canon EF 50mm f/1.4 USM lens is a fast aperture lens suitable for landscape and portrait photographers, as well as for reportage photographers.
This is a professional lens focused on portrait photography. It has the widest aperture in Canon's EF lens range, giving you full control over depth of field and shooting in low light without the need for flash or long exposures. A wide aperture with a round aperture makes it possible to evenly blur out-of-focus areas and focus the viewer's attention on the foreground. The ring-type ultrasonic motor (USM) ensures fast and quiet focusing on the subject. There is also the possibility of electronic manual focusing.
The design of this lens consists of eight elements in seven groups, using a large aspherical lens with variable curvature and a moving element to ensure greater clarity and contrast in the image areas in focus. The EF 85mm f/1.2L II USM is capable of transmitting distance information to the subject to the E-TTL II flash system for more accurate exposure metering.
Another fast lens from Canon's professional L series with a large aperture, 35mm focal length and a wide 63-degree field of view. This optic features an internal floating focus mechanism and a rugged, rugged construction that is water and dust resistant. The EF 35mm f/1.4L USM has an eight-bladed aperture and an ultrasonic focus motor for lightning-fast focusing. The optical design includes eleven elements in nine groups, including a large aspherical element to obtain an image with scatter correction and ensure sharpness across the frame. The minimum focusing distance is only 30 centimeters. .
AF-S Nikkor35mmf/1.4G
The AF-SNikkor 35mmf/1.4G is a professional wide-angle lens with a focal length of 35mm and high aperture from Nikon's proprietary line. It was developed specifically for use with the Japanese company's FX format digital SLR cameras. The lens design consists of ten elements in seven groups, including one aspherical element to provide higher image sharpness and contrast. Thanks to the special NanoCrystal coating, unpleasant glare and halos are eliminated. With a nine-bladed aperture, the lens produces pleasing, soft bokeh. The AF-S Nikkor 35mm f/1.4G optics is good because it has a durable, waterproof magnesium alloy body and high build quality, which allows it to be used in the toughest conditions.
Sony 50mmf/1.4
Sony's fast aperture lens for branded A-mount DSLR cameras. This is an excellent portrait lens with excellent resolution across the frame and high image clarity. Its design consists of seven elements in six groups. The 50mm focal length, combined with a wide aperture, makes this lens suitable for portraiture and low-light photography. The circular bladed diaphragm provides beautifully blurred backgrounds. The Sony 50mm f/1.4 lens is compact in size and relatively light in weight (220 grams).
High-aperture optics are, of course, wonderful, but do not forget that high-quality lenses with a wide aperture are not cheap. High aperture allows you to shoot at faster shutter speeds and at lower ISO values in various lighting conditions. However, when choosing a lens, think about how often you will actually need the widest aperture when shooting. If you don't often use wide apertures, then maybe you shouldn't go for high aperture, but it's better to pay attention to other lens parameters.
Surely, if you bought a lens, you have heard such a thing as lens aperture. Most likely, it was the aperture that played a key role when choosing a particular lens, and of course the seller tried to sell you a more expensive lens precisely referring to this mystical parameter - aperture, as if it would solve all your problems;)
First, let's figure out what lens aperture is, and what it is eaten with. Simply put, aperture is the throughput of the lens, i.e. Aperture refers to the maximum amount of light that passes through the lens and hits the sensor of a digital camera. The larger the aperture of the lens - the more light can pass through it, the more opportunities when shooting in poor lighting without using a flash or tripod.
The lens aperture depends on the following parameters:
- diaphragm
- focal length
- optical quality
We will not delve into physics, I will only say that the ratio of the maximum open diameter to the focal length will be your aperture ratio (the so-called geometric aperture ratio of the lens). It is this aperture ratio that optics manufacturers indicate on their lenses, for sure you have seen the following signatures - 1: 1.2, 1: 1.4, 1: 1.8, 1: 2.8, 1: 5.6 and so on. Naturally, the larger this ratio, the greater the aperture ratio of the lens. Therefore, fast lenses are considered those with a ratio of 1:2.8, 1:1.8, 1:1.4 or more.
For the record, the world's fastest lens was made in 1966 for NASA, who used it to capture the dark side of the moon. It is called Carl Zeiss Planar 50mm f/0.7 and its aperture ratio is 1:0.7, only ten such lenses were produced.
Every photographer, whether he is a beginner or a pro, knows that the fastest lenses are portrait lenses with a fixed focal length. And of course, every self-respecting photographer has such a lens in his arsenal. Another plus of fast fixes is that they are relatively inexpensive, for example, when compared with fast zoom lenses, but no less high quality.
Fast lenses are ideal for portrait photography because they give a small aperture, which is very important for .
Which portrait lens should I choose, aperture 1.2, 1.4 or 1.8?
There is the fact that beginners want to buy a faster lens, and of course sellers are happy to sell them this lens, which costs many times more. The only question is whether you need to overpay for the f / 1.4 aperture if you practically do not use it!
?Then I took another photo, which is doing well: the face is in focus and the background is blurred, but the aperture was already f / 2.8.
I messed up a lot of frames before I realized that f / 1.2 should only be used if there is not enough light to shoot and then, this does not always help, it's easier to increase, especially if you have . Sometimes, even at 50mm prime with f/2.8 aperture, you can miss and many details will be out of focus, so I always play it safe, especially when photographing models, in good light I use aperture no smaller than f/3.2.
As you can see, the depth of field is quite noticeable.
Having decided to choose a new lens for your SLR camera, you should decide what parameters it should have. Among the important points that significantly affect the quality of the result is the lens aperture. What is the aperture ratio of a photo lens, what tasks does it help to solve, which optics are fast aperture and other issues later in the article.
What is lens aperture
The amount of light that enters the camera's matrix depends on how fast the lens is used by the photographer. Aperture (denoted by the letter f) shows how powerful a stream of light will reach the target. After all, the glass or plastic from which the lenses are made is not completely transparent and part of the light flux is scattered on the way to the matrix. Light is refracted in different directions, part of it is absorbed by the lenses.
The wider, the more light it can let in. Aperture is indicated based on the diameter of the maximum open aperture and to the subject. The smaller this ratio, the higher the aperture ratio.
The amount of light that hits the matrix depends on:
- depth of field of the image;
- the ability to create a high-quality picture even with insufficient light.
Depth of field
Fast lenses allow you to sharpen only the main objects more sharply. For example, when shooting portraits. The number of objects in sharpness is determined by . The surrounding background is beautifully blurred, creating a so-called around the subject. This allows you to get rid of unnecessary details, hide an unattractive background. Such shots in many cases look much more impressive.
Quality even in low light
With a lack of lighting, the photographer can change 3 basic settings in the camera:, and the light sensitivity of the optics (). In this case, the shutter speed can only be changed to certain values, so as not to get. High ISO values can degrade the quality of the frame, as digital noise will appear. It remains to use aperture, that is, the maximum opening of the aperture. This indicator will not degrade the quality of the image and will help out in this situation.
What optics is considered fast
Fast lenses are also called fast and bright lenses. This type of optics includes models in which the maximum open aperture (f) starts from 2.8. For example, Sigma 17-50mm F2.8. The aperture can be opened even wider, as in Nikon 50mm F1.4G portrait fixes.
There are also super fast lenses. For example, Nikon 50mm F1.2 MF.
At the same time, beginners should take into account that it is better not to open the aperture to the maximum indicated on the optics. For example, at the specified f1.4, the working aperture starts at about f1.8 and even f 2.0. And at f1.4, even the main object in the frame may not be very clear.
Advantages and disadvantages
Cameras equipped with high aperture optics offer a lot of advantages and some disadvantages.
Advantages
Among the advantages:
- High quality and brightness of photos;
- The ability to get bright and spectacular shots even with a lack of light;
- Shooting at short shutter speeds "handheld" in any light;
- The speed of some types, which is especially helpful when using filters;
- Beautiful bokeh that allows you to make artistic portraits even in the absence of a suitable background;
- The ability to create original photographs. For example, when shooting a portrait, focus on the eyes and leave the rest of the face blurry;
- Shooting at low light sensitivity (ISO) without fear that the frame will be spoiled by digital noise;
- Bright and bright image in the viewfinder, which makes it easier to find a convenient angle and focus. Especially if you focus manually. You don't have to squint too hard to strain your eyes.
disadvantages
- The main disadvantage of high-aperture glasses is their high cost. Especially when it comes to zoom lenses - that is, optics with variable . Fast fixes, such as Nikon 50mm F1.4G, are cheaper. But then you have to get an additional lens, because a fixed distance is not suitable for all types of shooting. It's great for portraits, but won't do well for reportage. Especially if the objects being shot are at a great distance from the camera. In this case, zoom is indispensable;
- Also a disadvantage can be considered a strong blurring of surrounding objects when shooting at maximum aperture values. Especially when, according to the photographer's idea, several objects should be sharp at once, and shooting conditions, for example, lighting, do not allow closing the aperture too much to increase the depth of field.
When a fast lens is needed
Amateurs who shoot only everyday scenes and do not strive to develop in photography, may well get by with cheaper optics and the aperture ratio is not so important. Professional cameras with fast lenses come in handy in the following situations:
- When shooting sports or wildlife. In this case, it is important to set the shutter speed as fast as possible so that objects moving at high speed are not blurred.
- For shooting professional shots in the evening or at night. In such conditions, a good lens aperture is indispensable. High-aperture lenses help to catch and use even low-light objects.
- To compensate for the low light sensitivity of the camera matrix. Aperture is able to smooth out such a lack of a camera.
- For creating high-quality photo reports in rooms with insufficient lighting. For example, in nightclubs, restaurants, fashion shows or dance competitions.
Enlightenment and luminosity - different concepts
Which fast lens to choose
In general, high-aperture optics are divided into 2 types: fixed and zoom lenses.
Fixes are great for studio shooting, where you can easily change the distance to the object, moving around the room. And the model is static. Fixed lenses are good in picture quality. Their design has fewer optical elements, which reduces the number of distortions.
Beginners most often choose optics with a fixed focal length from 50 to 55 mm, with aperture ratios from 2.8 to 1.4. Such lenses are also called "fifty dollars". They can be found in the lines of all the most famous manufacturers of photographic equipment. These parameters are quite enough if the photographer does not have the desire to engage in subject or night photography.
In second place in popularity are fixes with a focal length of 30 and 35 mm. They are wide-angle and are suitable for a large number of tasks. But at the same time, they slightly distort the perspective, which adversely affects portrait photography.
Those who specialize in close-up portraits prefer 85mm and 135mm primes. And the longer the focal length of the optics, the greater the bokeh effect.
Among glasses with a variable focal length, models with a focal length of 17-55 mm are most popular. By adding optics with a distance of 70-200 to them, you can confidently shoot high-quality reports. In the presence of course the skills of reportage shooting.
Aperture is an important parameter in a lens. It helps to take high-quality pictures even in difficult conditions, for example, with a lack of light. However, fast optics are not cheap, and in the case of fixes, most likely, you will need more than one - with different focal lengths. Therefore, a beginner can first try his hand at cheaper models. In the future, it will become clear whether you need a fast lens or whether ordinary kit (complete) optics can cope with the tasks.
In simple terms, the aperture of a camera is a device through which light enters the camera's matrix. The diaphragm consists of the so-called "petals", the number of which can vary from three to twenty pieces. Depending on the intensity of illumination, the petals reduce or increase the diameter of the light-transmitting hole. The principle of their action is similar to the pupil: in dim light it expands, in bright light it narrows.
To better understand the principles of calculating the characteristics of a lens (including the aperture value), it is necessary to know what the focal length of a lens is.
Lens focal length
Focal length- this is the distance between the camera matrix and the main optical plane of the lens, subject to its focusing to infinity. This indicator determines the viewing angle achieved by a particular lens. The longer the focal length, the smaller the viewing angle. The specifications usually indicate the minimum and maximum focal length that the lens provides. It is customary to measure it in millimeters.
The ratio of the focal length to the aperture size is called the f-number. That is what determines the aperture value. The smaller this indicator, the larger the hole, and the more light penetrates the camera matrix. It is worth considering that the aperture value is often indicated as a denominator of a fraction, without specifying the focal length.
Possible values of f-numbers are described by a special aperture scale, which is a sequence of numbers:
1 - 1.4 - 2 - 2.8 - 4 - 5.6 - 8 - 11 - 16 - 22 and so on.
The essence of the scale is that narrowing the aperture of the lens by half leads to a decrease in the amount of light entering the matrix by four times. A similar effect has a double increase in focal length. The aperture scale is often applied to the lens barrel for the convenience of the photographer.
Lenses with the smallest f-numbers (f/1.2 - f/1.8) transmit the maximum amount of light. Such lenses are called fast lenses.
Lens aperture
Aperture- this is the degree of attenuation of the light flux by the camera lens, or, in other words, the ability of the lens to transmit the real brightness of the object. The larger the aperture, the better the pictures taken in poor lighting conditions without using a tripod and flash are obtained. In addition, fast lenses allow you to take pictures with the shortest possible shutter speeds.
The aperture value is determined by the value of the maximum open aperture. Together with the focal length, it is usually indicated on the rim of the lens. So, for example, the inscription 7-21 / 2.0-2.8 means that with a focal length of 7 millimeters, the aperture ratio is 2.0. Accordingly, with a focal length of 21 millimeters - 2.8.
When choosing a lens, it should be borne in mind that the maximum open aperture is used very rarely. At the same time, the price of fast lenses is significantly higher. For most buyers, there is no point in overpaying for an indicator of 1: 1.2; it is quite enough to buy a more budget option with an aperture ratio of 1: 1.8.
Relative hole
The reciprocal of the f-number is called relative bore. The relative aperture value determines how many times the focal length of the lens exceeds the diameter of its aperture. On the lens barrel, this indicator usually looks like a 1: 2 fraction. Such figures mean that the hole diameter is half the focal length.
In different sources, the concepts of aperture value, relative aperture value and aperture itself are often described in a scientific, obscure language. In order not to make a mistake when choosing a camera and not get confused in the characteristics of the lens, it is worth remembering the dependencies that exist between them.
So, luminosity is a constant property of optics that cannot be changed or adjusted. It should be remembered that aperture has nothing to do with the current aperture value. As mentioned above, its value is equal to the value of the aperture in the maximum open position.
The relative aperture, unlike aperture, is a variable value. You can adjust it with the aperture.
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