65369 Photography from scratch 0

In this tutorial, you will learn: Photo lens. The device and the principle of operation. What is lens aperture. Lens care. Fix or zoom lens? What to look for when choosing and buying photo optics. Light filters.

In the first lessons, we examined the principle of operation of a digital camera, what basic elements it consists of, what types of cameras exist, their characteristics and how to choose a camera. It was the turn to talk about essential element camera, on which 70% of the quality of your photos depends - about the lens. Quite complex material with many new terms.

Camera lens is a very complex design. Typically, it consists of a series of glass lenses that refract and focus the light entering the lens. This enlarges the image of the scene being shot and focuses on a specific point.

The lens structurally consists of the following main elements: a system of lenses and spherical mirrors made of special optical glass, a metal frame and a diaphragm. There is a lens in the front of the lens, the main purpose of which is to collect light rays. Inside the lens, other lenses and spherical mirrors are already placed, which are responsible for the subsequent refraction of light and further image formation. The number of lenses or optical elements in the design of modern lenses can vary. Moreover, they can be connected to each other or, conversely, separated by an air space. The simplest lenses use a system consisting of one to three lenses. And in high-quality and expensive lenses, the number of optical elements made of various types of glass can reach ten or more.

Interchangeable lens device (three groups of lenses are visually distinguishable)

High precision of the relative positioning of the lenses in the lens is achieved by attaching the lenses in a metal frame. That is, the frame is not just a lens barrel, but a component that ensures the required distance between the lenses, as well as protects the optical elements from mechanical and climatic influences. The frame usually has several ring-shaped pieces. As a result of the rotation of one of these rings, axial movement the part of the metal frame in which the main lens unit is mounted. The design of the lens frames assumes the possibility of manual or automatic change of the aperture, that is, an adjustable aperture, capable of changing the number of light rays passing through the lens to the matrix of a digital camera.

Six-blade diaphragm

The lens diaphragm is an opaque shutter with a small hole in the center that simply cuts off light rays passing through the edges of the lens. Such a shutter in the overwhelming majority of lenses consists of thin crescent-shaped metal petals installed around the circumference between the lens lenses. These diaphragm blades can rotate simultaneously with each other, moving into or out of the space between the lenses. The diaphragm is used to change the depth of field (DOF). By reducing the size of the aperture, we can sharpen the frame.

Interchangeable lens elements

The lens device may include a focusing ring. It is used to manually focus the lens. By rotating the lens ring, the photographer can sharpen either the foreground or background. If the lens is equipped with an autofocus function, the focusing ring rotates automatically thanks to a special motor. When you press the camera shutter button, the lens automatically focuses in sharpness. Focus is usually locked by pressing the shutter button halfway.

Modern interchangeable lenses from leading manufacturers use an ultrasonic focusing drive (USM) built directly into the lens. Thanks to it, a very fast focusing speed is provided. There are lenses with a so-called screwdriver drive, which mechanically connects the lens and the camera. This system is slower and noisier.

Types of Canon Ultrasonic Focusing Lenses

In addition to autofocus, a stabilization mechanism is often built into the design of the lens, which compensates for camera shake at slower shutter speeds, thereby allowing the photographer to get sharp shots in low light conditions without using a tripod. A zoom lens (zoom lens) has a dedicated zoom ring that is used to change the focal length. With the help of such a ring, you can zoom in or out of the subject in the frame.

The lens barrel can be integral with the camera only if the lens is rigidly integrated into the camera.

In digital cameras, designed for the use of interchangeable lenses, a lens mount system is used - bayonet. These lens-to-camera attachment systems vary from manufacturer to manufacturer, although there are some open mount standards. The size and shape of the mount depends on the type of camera to which the lens is attached.

The lens itself can, in turn, provide the ability to install a variety of filters. For this, it is equipped with a special thread around the outer lens. It is on this thread that various filters and other lens accessories are screwed, which we will talk about below.

Camera lenses are interchangeable or non-interchangeable.

Non-replaceable lenses are installed permanently and cannot be changed to others. Obviously, such lenses make the camera easier to handle, although this is not always convenient. For example, it is not possible to significantly change the focal length during shooting. All that remains is to take advantage of the ability to change the focal length of the non-interchangeable lens itself or use attachment lenses to obtain the effect of a wide-angle or telephoto lens. True, in most digital cameras, to select a suitable composition, it is possible to change the scale of the image by simply pressing the corresponding button.

Interchangeable lenses... The ability to change lenses depending on the specific situation during shooting is very convenient for controlling the creative process. For example, while standing in one place, you can first shoot with high quality the entire surrounding area with a wide-angle lens, and then a specific element of the scene with a telephoto lens. With a wide variety of lenses available, the digital camera offers the ultimate in shooting convenience and photo quality, although the kit of interchangeable lenses is expensive.

Lens specifications

Lenses are characterized by two main parameters - aperture and focal length. As a rule, the values ​​of these parameters are indicated on the front of the barrel of any lens.

Surely, if you have heard such a thing as a fast lens more than once. Most likely, it was the aperture ratio that played a key role in choosing a particular lens, and of course the seller referred to this mystical parameter - the aperture ratio!

First, let's figure out what the lens aperture is. If simply, then luminosity- this is throughput lens, i.e. aperture shows what maximum possible amount of light passes through the lens and enters the matrix of a digital camera. The more aperture the lens has, the more light can pass through it, the more opportunities it has when shooting in low light without using a flash or a tripod. In addition, the high-aperture lens helps focus the camera. Because this lens lets in more light, the camera can be better focused even in relatively low light.

The lens aperture depends on the following parameters:

• diaphragm
• focal length
• quality optics

We will not delve into physics, I will only say that the ratio of the diameter of the maximum open aperture to the focal length will be your aperture ratio (geometric aperture ratio of the lens). It is this aperture ratio that optics manufacturers indicate on the lens barrel - 1: 1.2, 1: 1.4, 1: 1.8, 1: 2.8, 1: 3.5-5.6 and so on. Naturally, the greater this ratio, the greater the lens aperture. Therefore, high-aperture lenses are considered those with a ratio of 1: 2.8, 1: 1.8, 1: 1.4 or more.

Focal length(FR) is one of the most important characteristics of a camera lens, which is usually indicated on the lens and is measured in millimeters. To be more precise, the back focal length is indicated - this is the distance from the optical center of the lens to the focus point.

Dependence of the angle of view on the focal length of the lens

From a practical point of view, focal length can be thought of as the magnification of the lens. The longer the focal length, the more the lens enlarges the image. With a large focal length, the image projected onto the sensors contains a smaller part of the scene being shot.

The focal length and sensor size determine the angle of view of the camera. For zoom lenses, the focal length range is indicated.

Depending on the focal length, a distinction is made between:

Wide angle lens ... Focal length up to 35-50 mm. This lens makes close objects appear even closer and distant objects even farther, while creating a strong sense of perspective. It is used when shooting landscapes, architecture, in confined spaces.

Normal lens (standard)... Focal length from 50 to 80 mm. The focal length of such a lens is approximately equal to the diagonal of the frame. The human eye provides an angle of view of about 50 degrees, which is what this lens provides, that is, the image is close to what we usually see, which is why it is called a normal lens. It is used when shooting portraits to prevent distortion of faces.

Telephoto lens... This type of lens has a focal length of more than 80 mm. Thanks to this, it greatly enlarges items. It is used in sports and any other reportage shooting where it is impossible to get closer to the subject.

Some of the lenses have constant focal length(such lenses are even more often called prime lenses), and do not have any "zoom". Advantages: usually, higher quality of the resulting image, higher aperture ratio. Disadvantages: Lack of "flexibility" in use. Usage: art photography and other types of photography, in which the impeccability of the "design" of the lens is important.

Lenses with variable focal length allow you to "zoom in" and "remove" the image in the frame. Advantages: ease of use, increased versatility, space saving (one such lens can, in fact, replace several fixes). Disadvantages: most often - the worst "picture" (this is mainly because when creating a design of zoom lenses, manufacturers have to make a number of compromises, including the introduction of additional lenses to expand the optical zoom limits of the lens), slightly less reliability due to the presence of moving elements , slightly more distortion, usually less bright than fixed focal length lenses. Usage: where versatility is needed. Very useful when traveling, when filming a reportage.

Lens quality

In the previous lesson, we talked about superzoom - compact cameras with lenses with a significant FR range (or so the lenses themselves are called). In this category, the disadvantages of zoom lenses are especially pronounced, despite the technical innovations of the manufacturers. It is impossible to optimally balance the optical formula of such a lens for quality work in the FR range, several tens or even hundreds of units. I would compare such a lens to a food processor - it can do everything, but everything is not good enough. Read more about superzoom on our resource. Therefore, when choosing a camera with non-interchangeable lenses or when buying a zoom lens, I would not recommend "chasing" the versatility of superzoom if you are primarily interested in the quality of photography. Such a purchase can only be justified for travel photos that do not pretend to be the cover of glossy magazines, and when the quality of your photos is determined by the criterion "Can you see me well? Did the pyramids come into the frame from behind?")))

When shooting in low light, high-aperture lenses produce sharp images at low shutter speeds. Regardless of the type of digital camera (fixed or interchangeable lenses), the lens has a decisive influence on the quality of the resulting image. High quality lenses always produce the sharpest, clearest images while retaining maximum detail in highlights and shadows.

So the most high quality photos are obtained with high-aperture lenses with fixed focal lengths, which is why most professional photographers prefer shooting with fixed focal lengths.

Identifying lens flaws

Despite assurances in high quality produced by the world's leading optics, it is recommended that you test your camera with a specific lens upon purchase. Even budget lenses are not cheap, and defects discovered after purchase can result in a loss of time in trips to warranty and service centers, and simply ruined mood from an unsuccessful purchase.

First of all, after a simple check of the lens for mechanical defects, fungal infections (due to improper storage from the seller) and dust between the lenses, a back-front focus test must be performed.

Concept back focus(back-focus, from the English "back" - back) means that when aiming at the focusing point, the lens missed backwards - the depth of field shifted back. At front focus(front-focus, from the English "front" - front), respectively, the miss occurs forward, the depth of field has shifted forward. To test an interchangeable lens, a special scale with a target is used, which must be downloaded from the Internet in advance and printed on a printer.

Read more about this and other checks (for sharpness, chromatic aberration) on our resource. If you still have a hard time understanding this, just remember these concepts - back focus and front focus. Return to this material later.

Lens distortion

Objective lenses refract and focus light to produce the final image. This may distort the image. Aberrations in photography, the distortion of images formed by the optics system is called. Depending on the nature of the origin, aberrations are chromatic and geometric.

If the contours of objects in the photograph have an unnaturally concave or convex shape, and this is not an artistic intention, this type of geometric aberration is called distortion... Distortion is most pronounced with wide-angle lenses.

Pincushion distortion Is a type of distortion in which the edges of the image bend inward. This distortion can occur in a zoom lens at maximum magnification and when attachment lenses are attached to short throw lenses. This kind of distortion is most noticeable on straight lines near the edges of the image. Pincushion distortion is usually corrected in an image editing program.

Barrel distortion Is the opposite of pincushion distortion. With barrel distortion, the image appears convex and straight lines curve outward. This distortion occurs when the magnification is set to very low in zoom lenses or wide-angle lenses. And this kind of distortion is most noticeable on straight lines near the edges of the image. Similar to pincushion distortion, barrel distortion can be in an image editing program.

Chromatic aberration- this type of optical distortion is due to the lack of focusing of light of different wavelengths at the same focal point. In this case, the short-wavelength light is refracted more than the long-wavelength, as a result of which there is a mismatch of light of different colors in the final image. This distortion is common in most consumer digital cameras that use lower quality lenses. Most professional camera lenses use low dispersion glass optics to minimize chromatic aberration. In addition, chromatic aberration is observed with inexpensive wide-angle lenses.

Colored halos at the bright edges, images are a form of chromatic aberration. This phenomenon occurs when light inside the lens creates magenta fringing along the edges of the image. This flaw is easily detected by the color fringing on the high-contrast edges of the captured image.

NOTE. The ability to eliminate pincushion, barrel distortion, and chromatic aberration in image editing software does not mean that these types of distortions should be neglected when evaluating lens quality. While it is not difficult to eliminate them in two or three images, it is much more difficult to do it in 100 or more images.

Lens Care

Cleaning the lens is a matter that must be approached responsibly from the very beginning of using the camera. Expensive photographic equipment needs attention and care, as careless use can lead to serious pollution, which will significantly reduce the quality of images and lead to premature wear or damage to the optics.

To care for the optics, use wet and dry wipes, cotton swabs, brushes for cleaning optics, blowing dust blowers. The market offers a wide range of various technical solutions for cleaning optics. Modern tools most often combine the above means.

Dry dust... Dust is considered an abrasive that can scratch the surface of the lens, so you need to remove it very carefully and do it first, in comparison with other dirt. Dry dust is best removed with an intense jet of air directed towards the lens surface at an angle of 10-35 degrees. If the speck of dust is not removed, you need to "process" it with a pear from different sides. Blowing with a pear is the first and most effective method of removing dry dust from optics, so it is quite enough.

Wet dust... Sometimes dust particles stick to the lens. In this case, a brush is used, which must be shaken off before use. The movement of the brush when removing dust particles should be short and soft, from the center to the edges with a slight twist to prevent dust from getting into the grooves between the lens and the lens. After successful cleaning of a speck of dust, the lens must be well blown with a pear.

Wet drops... It is advisable to remove wet drops before they dry, otherwise we will get abrasive microcrystals instead of liquid inorganic salts or organic fat. The microfibril wipes or sticks mentioned above are best suited for these purposes, as they instantly and almost completely absorb moisture. It is not necessary to press hard during cleaning, since this can squeeze out the already collected liquid and make scratches with unnecessary movements. It is worth wiping from the center of the lens to its edges in a spiral manner without effort, in short, delicate movements.

Dry drops... If the liquid does evaporate and leave salt crystals on the lens, to prevent micro-scratches, it is necessary to use special wet wipes, ending with a dry stick until the pollution is completely eliminated. If the objective lens has sufficient large diameter, for convenience it is worth using napkins, but in this case it is recommended to wear disposable gloves to prevent hand contamination of the napkin.

Greasy stains and fingerprints... This type of pollution is very common. In this case, it is best to use a special Lenspen, which allows you to conveniently and effectively remove dirt from the lens lenses.

Helpful hints.

1. Always use a special bag for transporting and storing the camera, additional optics and accessories, including cleaning products. The bag will protect the device from dust, thermal shock and mechanical shock, which are often during transportation.
2. When shooting in an area where there is a threat of dust or water droplets, use protective light filters from different manufacturers in advance, which, if deteriorated, are much cheaper than expensive optics.
3. Remember that even professional and skillful lens cleaning leaves behind invisible microscopic marks and micro-scratches that can eventually cause clouding of the optics, so keep your lenses clean from the very beginning and avoid unnecessary mechanical movements on the lenses and they will serve you for many years.
4. Never use your fingers to remove dirt from the lenses and do not use unsuitable materials. This can mechanically or chemically damage the delicate glass or lens coating.
5. Do not blow on the lens - microscopic droplets of saliva will definitely fall on the lens, no matter how you like it.
6. A clean, windless area is best suited for cleaning the optics. Before starting work, ensure that the workplace is as clean and lighted as possible and wash your hands.

​Light filters

Light filters are used to adjust the color, brightness and contrast of the photographed objects. They are also used to create various color and light effects. Most aspiring photographers believe that modern photography has gone quite far, so now you can safely do without light filters. Of course, modern technologies have gone far enough, but this does not mean that one can do without such a useful thing as a light filter in modern photography. Why do light filters continue to be used? Dealing with this is not so difficult. The main thing is to learn how to use and alternate them correctly, and the rest will follow.

Since light filters somewhat reduce the aperture of lenses, only a few are justified in digital photography. For amateur photography, it is sufficient and necessary to have the following filters:

Protective light filter. Serves to protect the outer lens from dust, rain and mechanical stress. It is often best to use ultraviolet (UV) in this role. Due to the high cost of the technological process, it turns out that the more expensive the filter, the less the loss of luminosity when using it. Therefore, the use of very cheap light filters is not recommended.

UV - filter. Designed to neutralize excess rays of the ultraviolet part of the spectrum, which color the general background in a bright blue color. The rays of this spectrum are not visible to the human eye, but are registered by the camera matrix. UV - light filters are indispensable when shooting in the mountains and in sunny weather - they remove blue haze and the color scheme looks more natural. When using a UV filter, the photos come out with a little more contrast, the sky is better drawn.

Polarizing filter. This filter is indispensable for landscape and architectural photography. It consists of two glasses with a special coating - by rotating one relative to the other, you can achieve the disappearance of reflections and glare from non-metallic surfaces such as water or glass.

On a sunny day, the sky and the sea become huge reflectors of all the sun's rays - this negatively affects the quality of the photo - it turns out to be faded and colorless. By using this light filter, the photographer gets an additional opportunity to saturate the color and improve the contrast as separate parts scenes and images in general.

Neutral filter... Serves to reduce the aperture of the lens in order to prevent overexposure when it cannot be done by aperture. Often used for moving water when slow shutter speeds are needed.

As you can see, even modern photography cannot do without "obsolete" light filters. And when choosing a compact camera, the presence of a thread on the lens for a light filter should be an additional argument for you in favor of a particular model.

Lesson # 3 results:

We learned about lenses, their design and specifications. We tried to figure out what kind of magic word "luminosity" is, and what kind of light filters and what is needed for a novice amateur photographer. We learned a lot of new terms.

Practical task:

1. Carefully study the terms mentioned in the lesson and try to remember them. In the future, we will often use them in our lessons.

2. Carefully study the lens of your camera, its markings. Attempt to perform the Front Back Focus Lens Check yourself.

3. Imagine that you really have to buy a portrait and telephoto lens (most in demand by amateurs) for your camera (if you have a compact camera, choose a model with interchangeable lenses for the task, if you bought it or plan to buy it). Based on your shooting tasks and capabilities, we choose a lens: from choosing a specific model, checking in a store to purchasing accessories.

4. Tell us about your opinion about the lens marked - 18-200 f / 3.5-6.3.

We are waiting for the results of the task at. There you can also ask questions about the material presented.

In the next lesson # 4: Practical basics of photography. Automation of a modern camera: autofocus, automatic exposure metering. How shutter priority and aperture priority modes work. How to make your photo stand out by controlling technical parameters... Using automatic and manual camera modes.

REFERENCE INFORMATION- Lens markings

Common notation

80-200mm; 18-55mm; 300mm, etc. - focal lengths. For fixed distance lenses, this is indicated as a single number. On zoom lenses, it is recorded as a range, the first number is the minimum FR, the second is the maximum.
- F: 3.5-5.6; F: 1.4 is the largest possible aperture. Can be specified as a range or as a single number. One number is indicated on fixed focal length lenses as well as on zoom lenses that provide a constant aperture at focal lengths. The range is indicated on budget zoom lenses and some professional ones, due to their design, are not able to provide a constant aperture.

Canon

• EF (Electro Focus) is the designation for the mount for autofocus cameras.
• EF-S (Electro Focus-short backfocus). Designation of the mount for cameras with an APS-C sensor.
• USM (Utlrasonic Motor) - The ultrasonic motor built into the lens is used for autofocusing.
• L (Luxury) - high-quality lenses, expensive and low dispersion lenses are used in the production, they are produced in a dust and moisture resistant housing.
• FT-M (Full Time Manual) - lens with constant manual focus.
• TS-E (Tilt-Shift) - special lenses with the ability to correct perspective by tilting and shifting the optical assembly.
• I / R (Internal Focus Rear Focus) - lenses with internal focusing or focusing by the rear group of lenses (with a non-rotating front lens, the lens length does not change when focusing)
• IS (Image Stabilizer) - optical image stabilization.
• DO (Diffractive Optics) - lenses with diffractive elements. They are distinguished by their small size and weight.
• MP-E (Macro Photo Electronic) - lenses designed for macro photography.
• Float is a system of floating lenses in the lens. Designed to eliminate aberration when focusing at short distances.
• CaF2 (Fluorite) - fluorite glass in the part of the objective lens. Used to reduce aberrations more effectively than Super UD.
• UD (Ultra-low dispersion) - lenses made of low dispersion glass, with a low dispersion value, used to reduce the influence of chromatic aberrations.
• S-UD (Super Ultra-low dispersion) is an ultra-low dispersion glass lens designed to reduce chromatic aberration.
• AL (Aspheric Lens) - aspherical elements, used to reduce aberrations.
• CA (Circular Aperture) - to obtain a circular aperture in the lens, a special shape of the petals is used.
• STM (Stepping Motor) - lenses with a stepping motor.

Nikon

• AI / AI-S (Automatic Indexing) - lenses without autofocus.
• AI-P - lenses without autofocus, similar to the previous ones, are additionally equipped with electronic exposure metering.
• AF (Autofocus) - autofocus lenses without a built-in focus motor.
• AF-N (AF-new cosmetics) - lenses with a narrower manual focusing ring.
• AF-D, D (AF-Distance Information) - lenses with the ability to transmit the distance to the object to the camera.
• AF-I (AF-Internal Motor) is the first generation of lenses with a built-in autofocus motor.
• AF-S (AF-Silent Wave Motor) is the second generation of autofocus motor lenses that do not require a “screwdriver” in the camera.
• CRC (Close Range Correction) - an optical element is installed in the lens, which reduces the effect of aberrations when focusing at a short distance.
• G (G-type) - lenses without aperture control ring.
  Micro (Macro) - lenses designed for macro photography.
• PC-E (Perspective Control) - lenses with perspective correction (tilt-shift).
• ED - The lens uses low dispersion elements to reduce chromatic aberration.
• IF is a monoblock (one-piece) lens, focusing occurs due to the displacement of the lenses inside the lens.
• DC (Defocus Control) - the lens has a bokeh control function.
• VR (Vibration Reduction) - image stabilizer.
• N - a technology that allows you to reduce glare and reflections by applying nanocrystals.
• DX - for cameras with APS-C format matrices.
• FX is a lens for cameras with a full-frame sensor.

Sony

• A (Alpha Type), - designation of the type of mount.
• CZ (Carl Zeiss) - lenses developed by Carl Zeiss for A-mount cameras.
• ZA (Zeiss Alpha) - lenses created by Sony Alpha for Zeiss.
• G (Sony Professional Lens) is a professional lens series that meets high standards.
• Vario-Sonnar, Planar T *, Sonnar T *, Distagon T * - designations of the lens design from Carl Zeiss.
• SAM (Smooth Autofocus Motor) is a cheaper motor than SSM.
• STF (Smooth Transition Focus) - the lens has an optical element, due to which the transitions between areas in focus and out of focus are displayed very smoothly.
• SSM (Super Sonic wave Motor) - ultrasonic motor.
• DT (Digital Technology) - lenses for cameras with APS-C matrix.
• D (Distance Integration) - the lens supports the function of transmitting distance information to the focused object to the camera.
• APO - The lens contains apochromatic elements to reduce chromatic aberration.
• xi - the function of changing the focal length by the built-in motor.

Pentax

• (D) FA - These lenses are designed for a full frame camera.
• DA (Digital) - lenses for cameras with APS-C sensor.
• DA-L (Digital, Plastic) - a lens similar to the DA, a lightweight version, the bayonet is made of plastic.
• DA * (Digital, Pentax's "L") is a professional line of lenses in a dust and moisture resistant housing.
• AL (Aspherical lens) - the lens contains aspherical elements to eliminate chromatic aberration.
• IF (Internal focus) - this lens is focused by moving the internal lens group.
• PZ (Power Zoom) - mechanical zoom drive.
• AF (Autofocus) - lenses with an automatic focusing system.
• SDM (Sonic Direct drive Motor) - lenses with a built-in ultrasonic motor.
• SMC (Super Multi Coating) is a multi-coated lens.
• K-series is a K-mount lens.
• A-series is a Pentax A mount lens.
• F, FA - lens for full frame cameras, equipped with aperture control ring.
• FA J is a full-frame autofocus lens without aperture ring.
• Limited - lenses produced in a limited series, compact design.

Sigma

• EX is an expensive series lens with improved optical and mechanical characteristics.
• ASP (Aspherical Lens) - Aspherical elements are used in the lens to reduce size and improve performance.
• APO (Apochromatic) - the lens is designed using low dispersion glass.
• OS (Optical Stabilizer) - built-in optical image stabilization system.
• HSM (Hyper-Sonic Motor) is a lens with a built-in ultrasonic motor.
• RF (Rear Focus) - This lens is equipped with a rear lens group focusing system.
• IF (Inner Focus) - when focusing, the inner lens groups are moved. Monoblock lens.
• Conv (APO Teleconverter EX) - can be used with APO Teleconverter.
• DG (DG Lens) - lenses with wide angles and large aperture, used for cameras with a full-frame sensor.
• DC (DC Lens) - lenses designed for cameras with APS-C matrix.

Tokina

• AS (Asperical Optics) - the lens uses aspherical elements to reduce aberrations.
• F&R (Aspherical F&R) - the lens is designed using an aspherical element of the F&R type. This technology achieves image quality with uniformly light edges and corrected spherical aberration.
• SD (Super Low Dispersion) - the design of the lens includes low dispersion elements, used to eliminate chromatic aberrations.
• HLD (High refraction, Low dispersion) is a technology to prevent the occurrence of chromatic aberration.
• MC (Multi-Coating) is a special transparent multi-layer anti-reflective coating that protects against reflections and unwanted glare, the technology is used to improve sharpness and color rendition.
• FE (Floating Element) is a special system of floating elements that move when the focal length changes, reducing the astigmatism of the lens.
• IF (Internal Focus) - internal focusing system, during focusing, the inner group of lenses moves, the outer parts of the lens do not rotate.
• IRF (Internal Rear Focus System) - the rear lens group moves during focusing.
• FC (Focus Clutch) is a lens with a focus lock mechanism.
• AT-X (Advanced Technology - Extra) - variable aperture lenses for modern SLR cameras.
• PRO - lenses of the professional line, with a constant aperture.
• One Touch FC is a system used in Tokina AT-X PRO lenses, to switch between automatic and manual focusing by moving the focusing ring.
• DC - an ultrasonic motor is installed in the lens.
• DX is a lens designed specifically for APS-C cameras.
• FX is a lens for full frame cameras.
• M (Macro) - the lens is designed for macro photography.

Tamron

• Di (Digital) denotes a new generation of lenses specially adapted to the requirements of digital SLR cameras.
• Di II (Digital-II) - This series of lenses is designed specifically for use in digital cameras with APS-C sensor.
• SP (Super Performance) is a line of lenses that meet the highest design requirements and excellent technical parameters.
• ASL (Aspherical) - to eliminate spherical aberration and distortion, the lens is equipped with aspherical elements.
• LD (Low Dispersion) - LD elements are made of special glass with an extremely low color index. The result is effective compensation for chromatic aberration.
• AD (Anomalous Dispersion) - the lens is equipped with glass with anomalous dispersion. Effectively compensates for axial chromatic aberrations in telephoto lenses and lateral chromatic aberrations in conventional wide-angle lenses.
• HID is a glass element in the lens that allows you to minimize chromatic aberration along the axis and in the corners of the frame.
• IF (Internal Focusing) - The lens is designed with an internal focusing system.
• ZL (Zoom Lock) - the maximum distance from which focusing is possible, allows you to perform macro photography in the Megazoom range.
• The SHM is a lightweight and extremely durable mechanism from Tamron, based on special plastic and stainless steel reinforcement for mounting the lens on the camera.
• USD (Ultrasonic Silent Drive) - an ultrasonic motor is built into the lens.
• BIM (Built-In Motor) - built-in motor, will allow the lens to be used on Nikon cameras that are not equipped with a "screwdriver".
• VC (Vibration Compensation) - the lens is equipped with a stabilization system.
• PZD (Piezo Drive) - piezoelectric autofocus drive.

Hello dear readers of my site! Today we'll talk about lenses. Let's consider what lenses are, their main parameters, as well as for what types of shooting is this or that lens better suited and why?

Better and more expensive lens than vice versa! I think many will agree with this statement, because the lens is the photographer's eye and it conveys the image. Now on the market there are different types lenses, each designed for a specific type of shooting.

Consider lens classification according to certain parameters.

By focal length.

• Wide or short throw. This class includes lenses with a focal length of less than 50 mm. Lenses with a focal length of 50 mm are considered to produce the most natural image that is similar to human vision. These lenses allow you to capture more space in the frame. Well suited for landscapes, indoor interiors, wide theatrical scenes. The result is a beautiful, sharp picture with great information content. This type includes Fisheye or Fisheye lenses. They have a viewing angle of 1800 and a focal length of 15mm. The image taken with such a lens turns out to be curled around the edges, as if inscribed in a circle.
• Standard or Normal. The focal length ranges from 45mm - 75mm. Versatile lenses as it is suitable for many types of photography. They are very often used to create portrait photographs.
• Telephoto or telephoto lenses ... The focal length of such lenses ranges from 75 mm. They do a good job when it is necessary to shoot distant objects.

By type of focus.

• Fixed focal length lenses (fixes). Such lenses have only one value, for example 50mm. Fixes, as a rule, have a higher aperture ratio, have less distortion, are simpler in design, which means they are cheaper. However, in order to compose an interesting shot, you will have to run your legs.
• Varifocal Lenses (Zoom). More versatile as both wide-angle and telephoto lenses can be used. Now, to build an interesting shot, it will be enough to turn the wheel on the lens. True, this type of lens has a lower aperture ratio, which decreases with increasing focal length. There are constant aperture zooms, but they cost an order of magnitude more. It is wrong to think that Zoom and Zoom are one and the same. Zoom is a maxi ratiominimum focal length to minimum and nothing else! For example, if we have a lens of 18 mm - 55 mm and, otherwise the calculations are unfair, then its zoom is approximately 3, but such a lens will not bring closer, but on the contrary, it will move away, since it was noted above thatHuman vision is similar to that of a 50mm focal length lens. Unfortunately, in-store consultants often try to portray 50x zoom as 50x magnification, which is fundamentally wrong!

By the presence of autofocus.

• With auto focus. It is necessary to separate the autofocus built into the lens and from the electric motor located in the digital camera, the so-called "screwdriver". Not all cameras have this "screwdriver" built in, so you have to buy more expensive lenses with their own autofocus.
• No auto focus. The focusing of the image is carried out by rotating the lens focusing ring. Dignity is their price.

​​ By image stabilization.

• With stabilization (with vibration reduction). More expensive lenses, but allow you to shoot sharp photos especially at slow shutter speeds or at long focal lengths. Anyway, useful function especially when shooting handheld.
• No stabilization. Ideal for shooting with a tripod or handheld at high shutter speeds. In this case, you do not have to overpay.

By aperture value or f-number.

When buying, you need to pay attention to the maximum aperture of the lens. Lenses with a wide aperture range are more flexible, both in terms of sharpness and possible shutter speed. How the range of possible aperture values ​​is indicated, we will consider in the next lesson.

By the presence of a diaphragm control ring.

Here it is simple, whether there is a ring on the lens to change it or not, then the control takes place through the camera.

By picking.

Usually, various accessories are sold with lenses in the kit. For example, lids, hoods, covers, there may even be filters. A trifle, but nice!

As you can see, the range of lenses is very wide and each type of lens has its own advantages and disadvantages. It all depends on the subject and the intention of the photographer. In the end, the photographer takes pictures, and the technique only helps him.

Lenses.
This article will focus on lenses. It is necessary to immediately make a reservation that it is designed mainly for those who are not very versed in technical features and terms. For this reason, some of the information will be omitted, and the main part will be presented as simply as possible.

Why lenses are needed.

Probably, everyone who has just purchased or is going to purchase a DSLR has wondered: why, in fact, you need such a variety of lenses, if a lens is already supplied with the camera (the so-called "whale"). For ordinary day-to-day tasks, such a lens is likely to be sufficient. However, there is an opinion that the more expensive and high-quality the lens is, the better it shoots, and this is true, but it must be borne in mind that it is not a technician who takes pictures, but a person. The lens is just a tool that gives great opportunities, and with the correct selection it will allow you to get the characteristics you personally lack.
Thus, first of all, it is necessary to decide for what purpose the lens is required, since there are not only universal lenses suitable for many tasks, but also very specific lenses, for example, telephoto lenses or tilt-shift lenses.

So what is a lens? Wikipedia says: a lens is an optical device designed to create a valid optical image. In optics, it is considered as equivalent to a converging lens, although it may have a different look, for example, "Camera obscura". Typically, a lens consists of a set of lenses (in some lenses, mirrors), designed to compensate for aberrations and assembled into a single system inside the frame. Simply put, it is a frame-mounted lens system that focuses the image on the camera's sensitive element (film or matrix).
Today on the market there are a huge number of different lenses in a wide price range, they are produced by different companies and have different characteristics. Every camera manufacturer (eg Canon, Nikon, etc.) produces “lenses” for their devices, which have their own lens connector - the so-called “bayonet”. In addition, there are third-party companies that make lenses for different brands of cameras. The most famous of them are Sigma and Tamron, lenses from Tokina, Samyang, etc. are less common. When choosing, it is worth clarifying whether the lens works stably with your camera and it is advisable to check the lens before buying. However, when choosing a lens, the manufacturer is far from the main thing that is worth paying attention to. The characteristics, which will be discussed later, are much more important.

Lens specifications

The main characteristics of lenses are as follows:
Focal length (and the ability to change it);
Lens field of view;
Aperture ratio;
Maximum relative aperture (sometimes incorrectly called aperture ratio);
Mount type or thread diameter for camera attachment - for interchangeable photographic or cinematographic lenses.
In addition to them, there are some more additional characteristics (of various kinds aberrations, resolution, etc.), which we will not touch upon.

Lens focal length
The job of the lens is to form an image on the sensitive element (film or matrix) of the camera. As you know from the school physics course, the focal length is the distance from the center of the lens to the focus (the point of intersection of the rays or their continuation refracted by the collecting / scattering system).

A lens is a collecting system of this kind that focuses the light entering it onto a matrix. The focal length of the lens is the distance from the optical center of the system to the sensitive element.

If we forget about theory and put it more simply, then the focal length of the lens characterizes the ability of the lens to bring objects closer. In order not to get confused, you can remember a simple formula: the longer the focal length, the closer the subject will be. The following are photographs taken from the same position, but using lenses with different focal lengths:

A visual representation of the principle of operation of the simplest lens:

Focal length is measured in millimeters. As a rule, its value is indicated on the lens itself.

Nikon AF-S DX Nikkor 55-300 mm lens
Code: 130335

Sony SAL-50 mm f / 1.4 lens
Code: 105758

According to the range of focal length values, the lenses are divided into prime and vario lenses. Fix is ​​any lens with a fixed focal length, a slang word, an abbreviation used to contrast zoom lenses.

Zoom lens - a lens with a variable focal length (zoom, "zoom").

Each type of lens has both pros and cons, which, however, are quite subjective. Fixes, for example, are much lighter and more compact, but zooms are much more versatile in terms of focal lengths. In some situations (wedding reportage, for example), zoom will allow you to get the desired composition with minimal effort on changing lenses and constant movement. If we compare fixes and zooms that are close in aperture and focal lengths, then you can sometimes get a two-fold superiority of the zoom in weight, which you will certainly feel, and the cost will be higher.
In addition to the focal length, there is another important detail that photographers should know about - the crop factor of the matrix.
The point is that there are so-called "normal" lenses - the perception of perspective in photographs obtained with such a lens is as close as possible to the perception of perspective by the human eye. The parameters of such lenses were calculated at the time of film cameras, which used 35 mm film. The focal length of such a lens is 50 mm.
However, the matrices of most modern SLR cameras are smaller in size than a frame on 35 mm film (crop matrix). Because of this, the part of the image at the edges, captured by the lens, simply does not fall on the matrix, that is, the viewing angle decreases. Therefore, for convenience, the term "equivalent focal length" is used for cameras with a crop sensor - a focal length at which the angle of view will be the same as on film at a real focal length.
Simply put, modern DSLR cameras with a crop matrix are designed in such a way that photographs are obtained a little closer in comparison with frames obtained with a film camera or full-frame matrices. It should be noted that lenses in all formats give the same image, the resizing of which depends only on the size of the matrix. For understanding, see the picture below. The red frame shows the boundaries of a regular 36 × 24 mm frame, and the blue frame shows the boundaries of a 22.5 × 15 mm digital camera.

Usually, in the descriptions of cameras, the so-called "crop factor" is indicated - a coefficient showing how many times the linear dimensions of the matrix smaller sizes film frame. As a rule, modern SLR cameras have this value in the range of 1.3-2.0. Among them, the most common crop factors are 1.5 and 1.6 (APS-C standard) and 2 (4: 3 standard (4/3 and Micro 4/3)). To calculate the equivalent focal length, the focal length indicated on the lens must be multiplied by the crop factor of the camera. For example, let's compare two lenses designed for different cameras:
1. The SMC Pentax-DA lens is marked "18-55 mm". The crop factor of the camera on which this lens is mounted is 1.53. Multiplying the focal lengths by the crop factor, we get the equivalent focal lengths (EFR): 28-84 mm.
2. The lens of the Olympus C-900Z camera is marked "5.4-16.2 mm". The crop factor of this unit is 6.56. Multiplying, we get the EGF of the lens: 35-106 mm.
Now, we can compare them. The first has a wider angle of view at the wide-angle position, the second at a longer telephoto position.

Classification of lenses by the angle of the field of view (focal length).

The classification of photographic lenses by the angle of field of view or by the focal length, referred to the frame size, is widely used. This characteristic largely determines the scope of the lens.

Schematic designation of focal length and their angle of view: 1.Ultra wide-angle lens. 2. Wide angle lens. 3. Normal lens. 4. Telephoto lens. 5. Super telephoto lens

A normal lens is a lens whose focal length is approximately equal to the diagonal of the frame. For 35 mm film, a lens with a focal length of 50 mm is considered normal, although the diagonal of such a frame is 43 mm. The field of view of a normal lens is 40 ° to 51 ° inclusive (often about 45 °). The angle of view of such a lens is approximately equal to the angle of view of the human eye. Such lenses do not distort the perspective of the frame.

Wide-angle (short-throw) lens - a lens with a field of view from 52 ° to 82 ° inclusive, the focal length of which is less than the wide side of the frame (20-28 mm). The objects in the background when shooting with this lens are smaller than we can see. It is often used for shooting in confined spaces, such as interiors, but can be distorted. Also used for landscape and architecture photography.

Canon TAMRON SP AF10-24mm F / 3.5-4.5 Di II LD Lens
Code: 153710

An ultra-wide-angle lens is a lens with an angle of view of 83 ° or more, and a focal length that is less than the small side of the frame (less than 20 mm). Ultra-wide-angle lenses have exaggerated perspective and are often used to add expressiveness to images. Fish-eye lenses have a viewing angle of about 180 ° and produce even more distortion.

TOKINA 11-16 f / 2.8 DX AF for Canon Lens
Code: 163907

TOKINA 10-17mm f / 3.5-4.5 AF DX Fish-Eye for Nikon Lens
Code: 163906

Portrait lens - if this term is applied to the range of focal lengths, it usually means the range from the diagonal of the frame to three times its value. For 35 mm film, a portrait lens is considered with a focal length of 50-130 mm and a field of view of 18-45 °. Concept portrait lens conditionally and refers, in addition to the focal length, to the luminosity and the nature of the optical pattern as a whole. The lenses are quite versatile. In photographs taken with this lens, the objects in the background are smaller than we see. Another issue is that when shooting portraits, they usually try to blur the background.

Canon EF 28-135 f / 3.5-5.6 IS USM Lens
Code: 112705

A long-focus lens (often referred to as a telephoto lens) is a lens whose focal length is much larger than the diagonal of the frame (150 mm). Has a field of view from 10 ° to 39 ° inclusive, and is designed for shooting distant objects.

Olympus M.ZUIKO DIGITAL ED 75-300mm 1: 4.8-6.7 Lens
Code: 159180

Lens aperture.

Aperture is the second most important lens parameter. Most often, the aperture ratio of the lens is misunderstood as the value of the denominator of the relative aperture (f-number). The f-number, the value of which is printed on the lens, only numerically characterizes the aperture ratio.
Generally speaking, the aperture ratio of a lens is a value that characterizes the degree of attenuation of light by the lens. The aperture ratio, more precisely, the geometric aperture ratio, is proportional to the area of ​​the effective aperture of the lens divided by the square of the focal length (the square of the so-called relative aperture of the optical system). That is, it depends on the geometric parameters - hole diameter and length. Effective lens aperture - an aperture that defines the diameter of the incoming light beam hitting the film or matrix. If we consider the lens as a simple tube, then with the same diameter, more light will pass through the shorter one. Accordingly, in order to improve the luminosity of the longer tube, we will have to increase its diameter. When passing through the lens, light is absorbed by the glass, scattered by the lens surface, experiencing various reflections inside the lens, etc. The aperture ratio that takes into account all these losses is called the effective aperture ratio.
As mentioned above, a lens is a system of lenses in a frame through which light passes and is recorded by a photosensitive element. This frame contains an adjustable "limiter" of the light flux, called the diaphragm.

The wider the aperture is open, the more light hits the sensor, the brighter the picture will be. Illustrated below is aperture size versus f-number.

Moving the aperture by one division changes the relative aperture by ≈1.41 times, while the illumination changes twice. The aperture scale is standard and looks like this: 1: 0.7; 1: 1; 1: 1.4; 1: 2; 1: 2.8; 1: 4; 1: 5.6; 1: 8; 1:11; 1:16; 1:22; 1:32; 1:45; 1:64. However, the first aperture numbers on the lenses may not coincide with the standard ones (1: 2.5; 1: 1.7). Typically, f-stop numbers are indicated on lenses and indicate the maximum aperture at a given focal length.

Using the diaphragm, you can not only adjust the amount of light, but also set the required depth of field (DOF). In other words, adjusting the aperture will blur the background. The more the aperture is open, the shallower the depth of field will be (the more blurred the background). This technique is usually used for portraits, that is, where a strong emphasis is needed on the foreground subject. An open aperture forms a circle, a partially closed aperture forms a polygon. The type of this polygon determines the "bokeh" - artistic blurring of point light sources, objects that are out of focus. The more edges (aperture blades), the more beautiful the "bokeh".

Lenses can be specified with one or two (for zoom) f-number values. That is, there is a constant and variable aperture of the lens.

Nikon Nikkor AF-S 50 mm f / 1.4 G lens
Code: 300145

Sony SAL-1118 DT 11-18 mm F4.5-5.6 lens
Code: 102042

Constant aperture is typical for fixes. For zooms, a change in focal length entails a change in aperture ratio (as we remember, it is inversely proportional to the square of the focal length). However, zooms can also have a constant aperture. This is quite convenient, for example, when shooting with a flash, since there is no need to take into account the change in aperture. Such lenses are always a little more expensive due to the complexity of the design.

Typical values ​​of the denominator of the maximum relative aperture of lenses of different classes:
Low-volume unique lens for the NASA space program Carl Zeiss Planar 50mm f / 0.7: 0.7.
Leica Noctilux for rangefinder camera: 0.95.
Jupiter-3 for a rangefinder camera (optical design "zonnar"): 1.5.
Fixed focal length lenses for SLR cameras: 1.2 - 4.
Digital Autofocus Compact Camera: 1.4 - 5.6.
Mid-range zoom lens for DSLRs: 2.8 - 4.
Inexpensive zoom lens for SLR cameras: 3.5 - 5.6.
Autofocus compact camera: 5.6.
Film compact camera: 8 - 11.

To understand all of the above: a faster lens is the one with a smaller f-number. For amateur photography, an average f / 4 is usually sufficient. Therefore, the inexpensive f / 3.5 - f / 5.6 zooms are recommended for beginners, which will be enough for most everyday tasks.

Stabilizers and ultrasonic motors.

When shooting in low light conditions or with slow shutter speeds, the frames are often blurry. Shaking hands or other reasons may cause the frame to be hopelessly spoiled. This is where technologies come to the rescue to help stabilize the image.
The camera has built-in special sensors that work on the principle of gyroscopes or accelerometers. These sensors constantly determine the angles of rotation and the speed of movement of the camera in space and issue commands to electric drives that deflect the stabilizing element of the lens or the matrix. With electronic (digital) image stabilization, the angles and speeds of movement of the camera are recalculated by the processor, which eliminates the shift.
There are three types of stabilizers: optical, with a movable matrix and digital.

Optical Image Stabilizer.
In 1994, Canon introduced a technology called OIS (Optical Image Stabilizer). The stabilizing element of the lens, movable along the vertical and horizontal axes, is deflected by the electric drive of the stabilization system on command from the sensors so that the projection of the image on the film (or matrix) fully compensates for the vibrations of the camera during the exposure. As a result, at low amplitudes of camera vibrations, the projection always remains stationary relative to the matrix, which provides the picture with the necessary clarity. However, the presence of an additional optical element slightly reduces the lens aperture.
OIS technology has been adopted by other manufacturers and has proven itself in a wide range of telephoto lenses and cameras (Canon, Nikon, Panasonic). Different manufacturers call their implementation of optical stabilization differently:

Canon - Image Stabilization (IS)
Nikon - Vibration Reduction (VR)
Panasonic - MEGA O.I.S. (Optical Image Stabilizer)
Sony - Optical Steady Shot
Tamron - Vibration Compensation (VC)
Sigma - Optical Stabilization (OS)

For film cameras optical stabilization is the only technology to combat “shake”, since the film itself cannot be moved like the matrix of a digital camera.

Image Stabilizer with Moving Matrix.
Konica Minolta has developed Anti-Shake (Anti-Shake) technology specifically for digital cameras, first used in 2003 in the Dimage A1. In this system, the movement of the camera is compensated not by the optical element inside the lens, but by its matrix, fixed on a movable platform.
Due to this, lenses become cheaper, simpler and more reliable, image stabilization works with any optics. This is important for SLR cameras with interchangeable lenses. Stabilization with a matrix shift, in contrast to optical, does not introduce distortions into the picture (perhaps, except for those caused by uneven sharpness of the lens) and does not affect the lens aperture. At the same time, it is believed that sensor shift stabilization is less effective than optical stabilization.
With an increase in the focal length of the lens, the effectiveness of Anti-Shake decreases: at long foci, the matrix has to make too fast movements with too large an amplitude, and it simply ceases to keep up with the “elusive” projection.
In addition, for high accuracy of operation, the system must know the exact value of the focal length of the lens, which limits the use of old zoom lenses, and the focusing distance at a short distance, which limits its operation in macro photography.
Stabilization systems with a movable matrix:

Konica Minolta - Anti-Shake (AS);
Sony - Super Steady Shot (SSS) - is an adaptation and development of Anti-Shake from Minolta;
Pentax - Shake Reduction (SR) - development of Pentax, found application in Pentax K100D, K10D and subsequent SLR cameras;
Olympus - Image Stabilizer (IS) - used in some models of SLR cameras and "ultrazoom" Olympus.

Electronic (digital) image stabilizer.
There is also EIS (Electronic (Digital) Image Stabilizer - electronic (digital) image stabilization). With this type of stabilization, approximately 40% of the pixels on the matrix are assigned to image stabilization and do not participate in the formation of the picture. When a video camera shakes, the picture "floats" across the matrix, and the processor fixes these fluctuations and makes corrections using spare pixels to compensate for the shaking of the picture. This stabilization system is widely used in digital video cameras, where the matrixes are small (0.8MP, 1.3MP, etc.). It has a lower quality than other types of stabilization, but it is fundamentally cheaper, since it does not contain additional mechanical elements.

Modes of operation of the image stabilization system.
There are three typical modes of operation of the image stabilization system: single or frame (English Shoot only), continuous (English Continuous) and panning mode (Panning).
In the single-shot mode, the stabilization system is activated only for the duration of the exposure, which, in theory, is most effective, since it requires the smallest corrective movements.
In continuous mode, the stabilization system works continuously, making it easier to focus in difficult conditions. However, the efficiency of the stabilization system in this case may turn out to be somewhat lower, since at the time of exposure the correcting element may already be displaced, which reduces its adjustment range. In addition, in continuous mode, the system consumes more power, which leads to a faster discharge of the battery.
In panning mode, the stabilization system only compensates for vertical vibrations.
It is fair to assume that the presence of stabilization in the lens affects the cost. Therefore, with a limited budget, it is worth deciding how critical this parameter is for you. Stabilization makes more sense when shooting distant subjects, low light, or slow shutter speeds. Consequently, if you are looking for a wide-angle or portrait lens for shooting mostly static subjects, you can save on stabilization.
In some cases, focusing quickly on the subject is important to get a great shot. To do this, manufacturers equip some of their lenses with more expensive ultrasonic (piezoelectric) motors.

Ultrasonic autofocus lens motor.

Here is a list of designations from various manufacturers:
Canon - USM, UltraSonic Motor;
Minolta, Sony - SSM, SuperSonic Motor;
Nikon - SWM, Silent Wave Motor;
Olympus - SWD, Supersonic Wave Drive;
Panasonic - XSM, Extra Silent Motor;
Pentax - SDM, Supersonic Drive Motor;
Sigma - HSM, Hyper Sonic Motor;
Tamron - USD, Ultrasonic Silent Drive, PZD, Piezo Drive.

Purpose of lenses.

The purpose of the lens is essential. Before we start shooting, the question always arises about what we will shoot. Lenses are divided by purpose as follows:
Portrait lens- used for shooting portraits. Should give a soft image without geometric distortion. Telephoto or fixed focal length lenses in the range of 80-200 mm (for 35 mm film) are often used as portrait lenses. The classic are 85 mm and 130 mm. A specialized portrait lens is designed so that it shows minimal aberrations when focusing from a few meters, that is, when shooting a portrait, to the detriment of the image quality "at infinity". A large (better than 2.8) aperture is almost mandatory for a portrait lens, and the nature of the bokeh is very important;
Macro lens- lens specially corrected for shooting from finite short distances. Typically used for macro photography of small objects. close-up, up to 1: 1 scale. Allows you to shoot with increased contrast and sharpness. They have a lower aperture ratio than other types of lenses of similar focal length. Typical focal lengths are 50 to 100 mm. In addition, it usually has a special frame;
Long focal lens- usually used for shooting distant objects. A long-focus lens in which the distance from the front optical surface to the rear focal plane is less than the focal length is called a telephoto lens;
Reproduction lens- used when reshooting drawings, technical documentation, etc. Must have minimal geometric distortions, minimal vignetting and minimal curvature of the image field;
Shift lens(shift lens) - used for architectural and other technical photography and prevents distortion of perspective.
Tilt lens(tilt lens) - is used to obtain a sharp image of extended objects that are not perpendicular to the optical axis of the lens during macro photography, as well as to obtain artistic effects.
Tilt-shift lens- a class of lenses that combines shift and tilt of the optical axis. Allows you to use the capabilities of gimbal cameras in small format photography. The largest manufacturers of photographic equipment have at least one such lens in their optics line, for example, Canon TS-E 17 F4L.
Stenop(pinhole) (pinhole camera lens, small hole, from the English pinhole) - is used for shooting landscapes or other objects with very long exposures and with obtaining an equally sharp image in one frame from macro distances to infinity;
Soft lens(soft focus lens, from the English soft) - a lens with undercorrected aberrations, usually spherical, or with distortionary structural elements. Use to obtain the effect of blur, haze, etc. while maintaining sharpness. Used in portraits. The so-called “soft focus filters” give a slightly similar effect;
Superzoom(travel zoom) is a versatile zoom lens of relatively low weight and maximum focal length range. It is used with reduced requirements for image quality and increased requirements for efficiency of use and weight.
Ultrasound- superzoom, which is characterized by increased magnification of the focal length range, usually starting from five.
Hyperzum- superzoom, the magnification of the focal length range of which is usually greater than 15. Common in professional camcorders and compact cameras, for example, Fujinon A18x7.6BERM, Angenieux 60x9.5, Nikon Coolpix P500 (magnification 36), Sony Cyber-shot DSC-HX100V (magnification 30 ), Canon PowerShot SX30 IS (35 magnification), Nikon Coolpix P90 (24 magnification). The image quality of the lens required in video cameras, especially standard definition, allows you to build lenses with high magnification. In addition, with a small diagonal of the matrices of video cameras and compact cameras, the dimensions of a zoom lens with a large range of focal lengths are incomparably smaller than they would be with the same parameters for the APS-C format. Studio camcorders can be equipped with zoom lenses with a magnification of 50 or even 100.

Lens attachment methods.

According to the method of attachment to the body of the device (camera, movie camera, film projector, slide projector, etc.), the lenses are divided into threaded and bayonet lenses - the former are fastened to the camera flange by screwing along the thread, the latter are fixed in it by turning. In the simplest designs, the lenses are held only by friction or are clamped by a yoke holder. Bayonet lens - (from the French baïonnette - bayonet) - a type of connection designed for attaching the lens to photographic, cinematographic, camcorders and digital film cameras. The main advantage over a threaded mount is the precise orientation of the lens relative to the camera, mainly relative to its mechanical and electrical connections... This is especially important for the mechanical transmission of the set aperture value to the exposure meter and for aligning the electrical contacts of modern lenses with microprocessors. In addition, the barrel of some lenses requires precise orientation in order to correct installation auxiliary equipment: devices for macro photography, follow-tricks and compendiums. The more technologically advanced and cheaper screw mount was supplanted in the 1950s by the bayonet mount, as the thread does not provide sufficient accuracy in mutual orientation. Another advantage of the bayonet mount is faster lens replacement.

There are many different types mounts, so when buying a lens (especially on the secondary market) you need to make sure that this lens is compatible with your camera. One of the two mounts that have remained unchanged since the advent of autofocus and digital photography is the Nikon F (F mount). It is a bayonet lens mount standard for small format single-lens reflex cameras, pioneered by Nikon in the Nikon F camera in 1959, and with some modifications is still used today, including in digital cameras. Another type of K mount that has survived to this day was developed by Asahi Pentax. The rest of the mounts are considered obsolete and replaced by fundamentally new ones, incompatible with previously released photographic equipment.
However, sometimes there is a desire to use in your work any lens with an outdated or unsuitable mount (from the old Zenit, for example) with your SLR camera. For lovers of vintage optics and experiments, there are various adapters and adapters that allow you to install lenses with a different mount.

Adapter М42 - Nikon F with lens and chip.

Lens selection.

For ordinary shooting at home, portraits of friends, street scenes and much more, a beginner is more than enough with the standard "whale" lens that comes with the camera. They have focal lengths of 18 - 55 mm or 18 - 105 mm, suitable for most ideas. An even more versatile lens is available, covering the full range from wide-angle to telephoto (18-200mm focal length), such as the TAMRON AF 18-200 / 3.5-6.3 XRLD DII, which remains the world's lightest and most compact zoom lens.

Nikon TAMRON AF 18-200 / 3.5-6.3 XRLD DII Lens
Code: 136362

If you gravitate towards the craft of photography and want to plunge into the world of photography as much as possible without special costs, then it makes sense to buy a prime lens for a standard lens. For example, everyone's favorite "fifty-kopeck piece" is a lens with a focal length of 50 mm or even 35 mm. With a lens like this, you can get decent bokeh, appreciate its aperture and feel like a real photographer as you move around in search of composition. Plus, it's lightweight and compact, making it a pleasure to work with.

Nikkor AF-S DX 35mm f / 1.8 G lens
Code: 126699

For shooting distant objects, a lens with a focal length of 70-300 mm is suitable, for example, Tamron SP AF 70-300mm F / 4-5.6 Di USD:

Tamron SP AF 70-300mm F / 4-5.6 Di USD Lens for Sony
Code: 160453

For those who want to take macro photography, there are inexpensive solutions in the form of lenses like:

Canon EF 50 mm F2.5 compact-macro lens
Code: 103480

There is an even more budgetary option - various attachments and macro rings.
Macro attachments are special lenses that are screwed onto the lens. They give quite a lot of distortion.
Reversing rings are devices for attaching the lens to the carcass backwards. The magnification is excellent, but there is no control over the aperture ratio.
Macro rings are the most suitable option for a test of strength in macro photography. They allow you to achieve a good magnification, however, like any additional glass in the system, they give some distortion and lead to a drop in the aperture ratio.

Practical photography Bunimovich David Zakharovich

How the lens works

How the lens works

Even the simplest modern lenses consist of two or three lenses, and the more advanced ones are even more complex.

In fig. 4 shows the Jupiter-8 lens. It has six lenses.

Rice. 4. The lens "Jupiter-8" has six lenses

Although a simple collecting lens gives an image, due to its inherent optical imperfections, the image is poor - sharp only in the central part and completely out of focus at the edges. Straight lines at the edges of the image are curved.

True, many of the disadvantages of a simple lens can be significantly mitigated by using diaphragms(an opaque shutter with a small hole in the center) by placing it in front of or behind the lens. This was the means used by the first photographers who did not have good lenses at their disposal. But with the use of aperture, the amount of light passing through the lens decreases many times, which naturally causes a significant increase in shutter speed during shooting.

The search for other methods that would improve the quality of the lens without reducing its effective aperture, already in the first years of photography showed that this can be achieved only by combining two or more lenses of a certain shape, made of special types of optical glass, in the lens. The first such lens was achromat(Fig. 5) - achromatic lens glued from two lenses. Then suggested periscope- a lens made of two freestanding lenses. Was later created aplanat, consisting of two free-standing achromats and which existed for almost 30 years as the best lens of its time, although it also had some optical disadvantages. And only at the beginning of our century it was possible to create the most perfect lenses, practically free from all the shortcomings. These lenses were named anastigmata.

Rice. 5. This is how the photographic lens was improved.

Currently, only anastigmata are produced, except for some simplified type cameras in which simpler lenses are installed. The optical schemes of anastigmata are very diverse and often very complex.

Photographic lenses, like cameras, are given names, for example: "Industar", "Russar", "Orion", etc. Sometimes these names are supplemented with one or another digital code, for example: "Helios-44", "Industar-50 ". Only occasionally does the name of the lens reflect design or other features. So, the letter "T" denotes three-lens lenses (triplets), the prefix "Tele" (for example, "Telemar") denotes telephoto lenses.

The main optical characteristics are indicated on the barrel of the front lens element next to the name. It is these characteristics that should be guided by when buying a camera.

All modern lenses provide a very clear and geometrically correct image of the objects being shot across the entire field of the photo frame, but the technical characteristics and associated optical properties are different for different lenses. Lenses differ in aperture ratio, main focal length, image field angle and resolving power. The aperture ratio and the main focal length are of the greatest practical importance. Numerical expressions of these characteristics are applied to lens mounts.

Rice. 6. The main technical characteristics of the lens are applied to its barrel.

Take a look at the lens barrel. In addition to the name and serial number you will see, for example, such as yet incomprehensible conventions: "1: 3.5" and " F= 5 cm "(Fig. 6). The first of them characterizes the aperture of the lens, the second expresses the magnitude of its main focal length... The meaning and meaning of these characteristics must be familiarized first of all.