Markings on the lens. Canon lens markings

In this article we present to you a breakdown of all the abbreviations that Canon uses to label its lenses. Knowing these symbols will help you make an informed decision when choosing a lens.

EF (Electro-Focus)– Standard mount for Canon cameras, lenses with this marking are suitable for any Canon SLR cameras.

EF-S (Short back focus)– Lenses designed for cameras with a cropped APS-C matrix. Canon EF-S lenses have a protruding lens and frame on the mount side, which makes it impossible to use EF-S lenses with full-frame cameras.

TS-E (Tilt-Shift)— Tilt-Shift lenses allow you to correct the perspective of an image by shifting or tilting a group of lenses relative to the optical axis. The lenses are used mainly in architectural and product photography.
In the near future we will devote a separate review article to these wonderful lenses and their capabilities.

MP-E (Macro Photography)– special versions of lenses with EF mount, but without electric focus. The second type includes only one specialized macro lens, the Canon MP-E 65 mm 1-5x Macro, which is capable of providing five times magnification without additional accessories.

L (Luxury)– A series of professional lenses with high degree protection from moisture and dust. The lenses in this series are only EF models, which usually have a fixed aperture ratio over the entire range of focal lengths. For external distinction, L series lenses have a red ring on the rim.

fisheye– Fisheye lens type. Ultra wide angle lens.

Macro– a prefix indicating that the optics belong to the macro line. First of all, it is characterized by a reduced minimum focusing distance.

IS (Image Stabilizer)– Image stabilization. The system contains a movable lens unit that compensates for camera movement when shooting. This allows you to shoot in low light with shutter speeds four stops longer than lenses without stabilization.

In new lenses, you can see the Roman numeral two next to the stabilization system, which means that the lens uses a second generation stabilization system.

USM (Ultrasonic Motor)– Ultrasonic motor for focusing. This motor runs quietly and quickly. Lenses with this motor are marked with a gold ring.

DO (Diffractive Optics)– The use of diffractive optics in the lens design, which reduces chromatic aberrations.
Lenses with this design are marked with a green ring.

IF– A lens design in which the internal lens unit moves when focusing. Due to the fact that the lens does not change its size, it focuses faster and is more convenient for working with filters for which their location is important, for example, polarizing and gradient ones.

RF— A lens design in which only the rear group of lenses is used for focusing. This speeds up the focusing process.

24-70 mm– Focal length range.

f:2.8– Maximum available lens aperture.

f:3.5-5.6— Range of maximum available apertures for zoom lenses. The range is related to focal lengths, this range is indicated for an 18-200mm lens, for 18mm the maximum aperture is f: 3.5, for 200mm, respectively, f: 5.6.

Soft Focus— Ability to control the degree of image softening. Used in several Canon lenses.

S-UD— The use of lenses made of ultra-low dispersion optical glass makes it possible to create lenses that are practically free of problems with chromatic aberrations.
Used in many L-series telephoto and super-telephoto lenses and wide-angle lenses.

AL— The lens design uses aspherical lenses, which eliminates spherical aberration. Currently, aspherical elements are installed in almost all EF lenses.

CA Circular Aperture— Circular diaphragm.

FT-M Full Time Manual— Most EF lenses equipped with an ultrasonic motor (USM) make it possible to adjust sharpness immediately after autofocus operation without switching to manual focus mode.

P.S.

The camera manual contains a list of compatible lenses; be sure to use this list when choosing a lens.

There are a lot of rumors about Canon lenses on the Internet, I admit honestly, until recently I myself was mistaken about the difference between EF and EF-S lenses. In this article, I tried to collect some information about them, which will help make a choice in favor of one modification or another, put an end to disputes and dispel some myths.

Let's first decipher the abbreviation EF - it comes from the phrase Electro-Focus (“Electrofocus”). With the EF mount comes an automatic focusing system built into the optics, i.e. There are no moving parts between the lens and the camera, only contacts, and the electric motor in the lens is responsible for focusing and aperture. By the way, the first EF series lens appeared back in 1987.

EF-S is a modification of the mount for cameras with an APS-C format matrix, which was developed in 2003. The "S" stands for Short Back Focus. The last optical element in such lenses is located closer to the matrix than in EF lenses. For comparison, I’ll give a picture of two lenses with different mount modifications.

Left lens EF, right EF-S

As you can see, on the right lens the last lens is located after the mount thread, i.e. when installed on the camera, it will be noticeably closer to the matrix. In fact, this is the only, but very important difference. The fact is that EF-S optics cannot be used with full-frame cameras. Despite the compatibility of the mount, a protruding lens can damage the camera mirror. Moreover, EF lenses are compatible and can be used with any Canon EOS cameras (DSLRs).

For APS-C format cameras, lens focal lengths must be adjusted. To calculate the focal length equivalent to that obtained on a full-format sensor, you need to multiply the values ​​indicated on the lens by 1.6. There is a widespread opinion on the Internet that for the EF-S series this is not necessary and the real values ​​​​are indicated on the optics, already taking into account recalculation. This is wrong. As an example, I will give a description of the new Canon EF-S 18-55mm f/3.5-5.6 IS II lens from the company’s official website:

The EF-S 18-55mm f/3.5-5.6 IS II is a high-quality, standard zoom lens that will appeal to photographers who prefer to travel light. With a focal length equivalent of 29-88mm in 35mm format…

As you can see, for these lenses the standard conversion of focal lengths is used and 18-55 turns into 29-88mm. A completely logical question arises: why bother with this entire garden? The fact is that this design made it possible to make lighter, smaller lenses. This is according to Canon, but in fact, it is quite possible that this is done so that inexpensive lenses are not used with expensive full-frame equipment.

Another interesting touch: neither the EF nor the EF-S were licensed to third party optics manufacturers such as Sigma or Tamron. Despite these manufacturers' claims of 100% compatibility, Canon does not provide such a guarantee. Therefore, when purchasing non-branded lenses, they must be tested especially carefully.

Let's draw conclusions about Canon lenses:

• focal length on APS-C cameras is recalculated for all types of lenses;
• ultra-wide angle on cropped cameras is only available with the EF-S 10-22mm lens;
• Unfortunately, fisheye on cropped cameras is not available at all;
• EF lenses are suitable for any Canon cameras;
• when upgrading from an APS-C camera to full frame, EF-S lenses cannot be used.

If you plan to upgrade to a full frame camera in the future, consider purchasing lenses in advance.

The website continues the series of articles about the markings and symbols of lenses from global photographic equipment manufacturers. In the last PhotoHack we discussed in detail. Today we’ll talk about their “sacred enemy” and, concurrently, the world leader in the production of photographic equipment - Canon.

Before starting the story about markings Canon lenses Let's take a short excursion into history: in 1987, a Japanese company offered the market a fundamentally new electron-optical photographic system - Canon EOS. Unlike its main competitor, Canon did not modernize the obsolete FD mount, but created new type EF mount, which met all the requirements of the new time and was the basis of the advanced Canon EOS system. This was a very bold step for the company. Canon could have lost a significant part of its customers, but, as they say, risk is a noble cause. Professionals highly appreciate the benefits new system and began to update their fleet of equipment. And for ordinary people, Canon launched a powerful promotional campaign in which it praised the simplicity and miraculous automation of EOS consumer cameras.

So, the first thing we see in the marking of any Canon lens (for example, EF 70-200mm f/2.8L IS II USM) is an abbreviation indicating the type of mount. Today, the EF mount has modifications EF-S and EF-m, which have both common and distinctive features from the main mount. Let's look at each of them in more detail.

E.F.(Electro– Focus) – the name of the bayonet mount of the Canon EOS system, which replaced the Canon FD mount produced from 1971 to 1987. EF is short for English electro– focus (electro-focus). The presence of the abbreviation EF in the lens name indicates not only its compatibility with all EOS cameras, but also imposes a number of other “default” characteristics. First, the bayonet mount has no movable mechanical connections between the camera and the lens: they are replaced by electrical contacts. Autofocus and aperture control is only possible electromechanically from the camera body. Secondly, all EF series lenses have a built-in autofocus drive motor.

As a result, buying a lens with the abbreviation E.F., you can be sure that it is compatible with all Canon EOS digital and film cameras without any restrictions and that it has autofocus regardless of the level of your camera (or professional).

The Canon EF bayonet mount is not compatible with the Canon FD mount. Of course, there are special adapters for working with old manual lenses on EOS cameras, but they are not compatible with all lenses in the FD line and have a number of limitations.

EF-S (Electro– FocusShortbackfocus) − designation of lenses designed specifically for digital SLR cameras(). Canon EF-S lenses appeared in 2003 along with the release of the first amateur digital SLR camera, the Canon EOS 300D. The letter “S” in the abbreviation “Short back focus” indicates a shorter distance from the rear lens to the matrix. Therefore lenses E.F.– S not compatible withE.F.-bayonet mount . But cameras using the EF-S mount work great with EF lenses. This means that the EF-S 15-85mm f/3.5-5.6 IS USM lens will work on both the EOS 1100D and EOS 7D, but you won't be able to use it on cameras with full-frame sensors (EOS 5D Mark II) or professional reportage cameras with APS-H sensor format (EOS 1D Mark IV).

Today, the Canon EF-S bayonet mount is used in the following cameras: EOS 7D, 20D, 30D, 40D, 50D, 60D, 300D, 350D, 400D, 450D, 500D, 550D, 600D, 1000D, 1100D and their modifications.

EF-M (Electro– FocusMirrorless) − lenses and mount type designed specifically for Canon EOS M mirrorless cameras. Lenses EF-M not compatible with mountsE.F. – S AndE.F. . But the latter can work with a Canon EOS M camera using a special Mount Adapter EF-EOS M.

Since Canon's EOS M mirrorless system was only introduced in 2012, this moment There are only two EF-M lenses: the Canon EF-M 22mm f/2 STM and the Canon EF-M 18-55mm f/3.5-5.6 IS STM. According to rumors, Canon will expand its line of mirrorless cameras and lenses for it.

T.S.– E (Tilt– ShiftEOS) − Canon non-autofocus lenses, with the help of which it is possible to correct the perspective of the image by shifting or tilting a group of lenses relative to the optical axis. Unlike its main competitor, Canon TS-E lenses have aperture adjustments from the camera body.

After the abbreviation indicating the type of mount or its modification, the marking of Canon lenses also indicates the maximum possible. For example, Canon EF 50mm f/1.8 II (you can read its review on our website) or, in the case of a zoom lens, EF-S 18-135mm f/3.5-5.6 IS STM.

50 mm, 18-135mm− focal length of a particular lens. Zoom lenses first indicate the minimum and then the maximum focal length.

f/1.8, f/3.5-5.6− maximum possible aperture values. All zoom lenses have two values: for the minimum and maximum focal lengths of a particular lens. In our case, at 18mm the maximum possible aperture value will be 3.5, and for 135mm – 5.6.

L (Luxury)− the red letter “L” paired with a red ring around the front lens indicates professional Canon lenses. Characterized by high quality images, high price, heavy weight and the presence in the design of fluorite, ultra-low dispersion or ultra-low dispersion elements, anti-reflective coatings, etc. Many lenses in this series are protected from dust and moisture.

IS (Image Stabilizer)− indicates that the lens has image stabilization. Also, the inscription “Image Stabilizer” is indicated on the lens body, near the bayonet mount. Canon first introduced in-lens image stabilization back in 1995. The Image Stabilizer system is currently in its fifth revision and allows you to take pictures with shutter speeds five stops longer compared to lenses without stabilization. For example, to avoid blur when shooting a static subject using an “unstabilized” Canon EF 85mm f/1.8 USM lens, you need to set the minimum shutter speed to 1/125. Using the Canon EF 70-200mm f/2.8L IS II USM, you can shoot the same object without blurring at a shutter speed of 1/5.

II− as in the case with, the Roman numeral is used when the lens model was updated, but the marking itself remained the same previous version: Canon EF 70-200mm f/2.8L IS II USM – Canon EF 70-200mm f/2.8L IS II USM, Canon EF 50mm f/1.8 II – Canon EF 50mm f/1.8. There is an opinion that the Roman numeral “II” denotes the generation of stabilization technology, which is not true.

USM (Ultrasonic Motor)− ultrasonic drive of the lens autofocus system. This drive is characterized by high focusing speed, low power consumption, and low noise level. Very often on lenses with a USM drive there is Golden ring around the front lens and the inscription Ultrasonic. Professional “L” series lenses also have the Ultrasonic inscription on the body.

Canon uses two types of USM motors: ring-type USM and micromotor USM (more a new version called Micro USM II). The first type is used in professional lenses and lenses in the mid-price segment, and the second type in cheaper ones. The average user should definitely know that lenses with ring-type USM motors have the function FT-M (Full Time Manual), which allows you to manually adjust focus regardless of the selected focus mode (analogous to Nikon’s M/A system). USM lenses with a micromotor (and, accordingly, Micro USM II) do not have such a function and can break if manual focusing is carried out in autofocus mode. The only exception is the Canon EF 50 f/1.4.

STM (Stepper Motor) − new technology autofocus drive, which provides multiple rapid movements of the focusing group of lenses over short distances, and with extremely low level noise. Lenses with STM motors are designed to work primarily with cameras that provide phase focusing using a matrix. At the moment this is only .

The main markings may contain the names of specialized lenses: Canon EF 100mm f/2.8 USM Macro or Canon EF 8-15mm f/4.0L fisheye USM. These names speak for themselves and do not need explanation.

IN model range Canon optics have two lenses, the name of which (including on the body itself) contains the abbreviation DO: EF 400 mm f/4 DO IS USM and EF 70-300 mm f/4.5-5.6 DO IS USM.

DO (Diffractive Optics)− lenses marked with this abbreviation are characterized by the presence of diffractive lenses in the optical design, which are designed to combat chromatic aberrations and distortion.

Canon also has the Canon EF 135mm f/2.8 lens SF (Soft Focus), which allows you to control the defocus of the image and control the degree of spherical aberrations in the foreground or background of the image.

All of the above abbreviations, numbers, letters and designations refer to markings that are indicated on the lens or accepted for classification within the optics line. But there are also designations that can be found in instructions, catalogs, official description on the website, etc. They mainly concern the optical properties of the lens and the focusing method.

IF (Internal Focusing)− monoblock lenses, in which focusing occurs by moving only the internal groups of lenses. Thanks to this, IF lenses do not change their size when focusing and their front element does not rotate, which makes it convenient to use gradient filters. The internal focusing system is implemented in most and some.

RF (Rear Focusing)− lenses in which only the rear group of lenses is used to speed up focusing.

Float− a system of floating lenses in the lens, used to eliminate aberrations when shooting at short distances.

AL (Aspheric Lens)− lenses have aspherical lenses in their design to combat spherical aberrations. Used in almost all EF lenses.

UD (Ultra-low dispersion)− lenses with low dispersion (scattering). Used in most lenses to minimize chromatic aberrations.

S-UD (SuperUltra-lowdispersion)− lenses with ultra-low dispersion (scattering). Almost all chromatic aberrations are removed. Used in many L-series telephoto and super-telephoto lenses and wide-angle lenses.

CaF2 (Fluorite) − indicates the presence of fluorite lenses in the lens to eliminate chromatic aberrations. Used in super telephoto lenses.

C.A.(CircularAperture) − involves the use of specially rounded aperture blades in order to obtain the “correct” bokeh.

In short, this is all I wanted to tell you about Canon lenses. As always, write your questions, comments and suggestions in the comments.

• E.F.– this format, introduced back in 1987, refers to a completely electronic lens mount to the camera body. Lenses designated EF are compatible with all EOS film and digital cameras and are capable of working with the full-frame 35mm format;
• EF-S– The only difference between Canon EF and EF-S lenses is the fact that the latter is designed to work with APS-C sensors, such as that found on the Canon EOS 700D camera. Canon EF-S lenses should not (and in most cases cannot) be mounted on Canon EOS film or digital cameras with a 36x24mm sensor size due to the larger mirror used in these cameras. When attached to such cameras, there is a risk of damage to the mirror when the shutter is released, which may hit the rear element. EF-S lenses are equipped with a special protective element that prevents them from being mounted on full-frame EOS devices;
• EF-M is a new lens format that was specifically designed for CanonEOSM mirrorless systems with EF-M mount. Like the EF-S, EF-M lenses are designed for cameras with an APS-C sensor. They can only be used with CanonEOSM system cameras due to their short flange distance (the distance between the lens mount and the film or sensor surface). At the same time, EF and EF-S type lenses can be mounted on the EF-M mount using appropriate adapters, but EF-M lenses cannot be mounted on the EF mount;
• FD- This is an old bayonet mount format for manual focusing, used in optics until 1987. Since this mount was not suitable for autofocus, the EOS system with an EF mount was developed. CanonFD lenses have now been discontinued, but the lenses are still used by film camera enthusiasts. There are several modified FD mount lenses that, using special adapters, can be installed on modern EOS EF cameras. An adapter with a special optical element allows you to focus at infinity, while conventional adapters do not allow this;
• CHO– lenses identical to FD lenses only without special coating of the front lens (meaning SSC coating, which allows you to cope with side and backlight and achieve excellent contrast);
• FL– lenses identical to FD lenses with the inability to work in shutter priority mode.

2) Abbreviation of Canon lenses depending on class and technology:

• L– belonging to the “Luxury” line. The L designation denotes top-end, professional lenses with the best optical characteristics and formulas using complex elements. These lenses are built to Canon's highest standards and are often weather-sealed and feature wide apertures. The cost of L lenses differs depending on their quality. For example, some lenses can be considered budget, for example the 24-105mm f/4 L lens. Its cost is over $1,100 at the moment, which is certainly not small. But for L-optics this price is more than acceptable. L lenses are easily recognizable thanks to the red ring on the body;
• SSC– Super Spectra Coating. Originally invented by Lord Rayleigh in 1886 and later refined by Carl Zeiss, this coating had a huge impact on the development of optics. In effect, this coating minimizes reflections and increases contrast. All modern Canon lenses are multi-coated and only older lenses are marked SSC;
• l, ll, lll– Roman numerals indicating the generation of the lens. For example, there are two Canon 24-70mm f/2.8L lenses: the first CanonEF 24-70mm f/2.8L and the second USM CanonEF 24-70mm f/2.8L ll USM. The only difference in the name is the "ll" designation on the second lens, which is actually an updated version of the first lens. Both lenses are professional L-class lenses, but with different optics and prices. Typically, if a lens gets Image Stabilizer (IS), it also means a newer release of the optic;
• USM– means that the lens is equipped with a top-end ring ultrasonic motor. This is a fast, quiet and powerful autofocus motor, which also allows you to manually adjust focus at any time. It is used in most modern Canon lenses, from inexpensive prime lenses to expensive L-class lenses;
• Micro USM– means that the optics use a simpler and smaller motor. Like its older brother, this motor is fast and quiet and is used in compact lenses with a small number of optical elements. A significant drawback is the fact that Micro USM does not allow manual focus adjustment at any time. But there are exceptions to this rule. One notable lens, the Canon EF 50mm f/1.4 USM, allows full manual focus when the Micro USM motor is engaged. At the same time, it is worth noting that both the presence of a USM motor in the lens and the equipping of the MicroUSM lens with a motor are indicated on the body in the same way, with the letters USM;
• STM– Stepper motor designed to minimize vibration and noise when recording video. This motor is gradually making its way into the budget segment of Canon optics. The first lens to use STM was the EF-M 22mm STM lens. So, all EF-M lenses currently have a stepper motor, and some EF-S lenses have received updated versions with an installed STM motor (for example, EF-S 18-55mm f/3.5-5.6 IS STM). On lenses with an STM motor, the movement of the focus ring is now measured in electronic value and then the data goes to the STM motor, which in turn drives the lens system;
• A.F.D.– The Arc-Form Drive was the first focusing motor to be used in Canon EF lenses. It is much noisier and slower compared to USM engines. Also worth noting is the slow response, as well as the inability to use manual focusing. If a lens with autofocus does not have motor data indicated on the body, then the optics are equipped with either an AFD motor or a MicroMotor;
• MM– this abbreviation stands for Micro Motor, which is essentially a smaller version of the AFD motor. This motor is used only in the cheapest Canon lenses such as the EF-S 18-55mm f/3.5-5.6 IS ll Kit. The motor does not allow you to use manual focusing at any time and produces quite a lot of noise during operation;
• PZ– a stand for zoom, which has a special motor for changing focal length. Perhaps the only lens that uses PZ is the EF 35-80mm f/4-5.6 PZ;
• IS– this abbreviation means image stabilization for Canon. Image stabilization refers to technology that moves the optical elements of the lens to counteract shake or shake, and allows for more accurate results with long shutter speeds and static lens positions.

3) Specialized designations for Canon lenses:

• Macro– a lens with this designation focuses at relatively short distances and provides a 1:1 magnification;
• Compact Macro– similar to regular Macro lenses, but can focus at very close distances (for example the EF 50mm f/2.5 Compact Macro lens). There is a special converter for this lens, which increases the flange distance (the distance between the sensor or film and the front lens of the lens) and makes it possible to magnify 1:1 for this optics (meaning the Canon Life-Size Converter EF);
• MP-E– there is only one lens with this designation and that is the Canon MP-E 62mm f/2.8 1-5x Macro. MP-E stands for very high magnification. The lens begins to focus at the distance that is the maximum for most macro lenses. This lens cannot focus at infinity. Instead, the user will have the option of magnification ranging from 1:1 to 5:1;
• TS-E– Tilt-shift lenses are used for creative portraits, landscapes, architectural or macro photography. They are exotic and expensive lenses with exclusively manual focus;
• DO– lenses using special Diffractive Optics lenses, which bend light more than regular glass. This allows them to be smaller than conventional lenses with the same parameters. A well-known example of such optics is the Canon EF 400mm f/4 DO IS USM lens. It, like the L lenses, has impressive build quality, but has a green ring on the body rather than a red one;
• Softfocus– as you may have guessed, Softfocus lenses have an optical formula that allows you to get a “softer” picture. These lenses were very popular several decades ago because they concealed skin imperfections in portraiture and created a special “soft” effect in the frame. It is worth noting that such lenses are not particularly popular nowadays, since the soft focus effect can be obtained in post-processing. There is only one Canon EF lens with Softfocus and that is the EF 135mm f/2.8 lens. You can turn off the Softfocus function by turning the corresponding ring on the lens and then the EF 135mm f/2.8 lens will work normally.

Lenses for Canon cameras There are quite a few, and sometimes they differ by just a few letters in the model name, and the price varies quite significantly. Therefore, let's collect a breakdown of these designations so that it is clear what technologies are used in this or that optics and what the buyer ultimately pays for. This article will only show models for Canon produced by the company itself, and in one of the following I will collect transcripts for the popular Sigma and Tamron lenses.

As an example, let's take the popular Canon EF 24-105 f/4L IS USM lens. Naturally, at the beginning there is the name of the manufacturer (Canon), then the type of lens mount or mount (), there may also be a designation for special lenses (TS-E and MP-E), it is understood that they also have an EF mount. The range of numbers or one value (24-105 in our case) reflects the focal lengths of the lens and the type - if there is one number, then it is a fixed lens, if the range is a zoom lens. Then comes the maximum aperture value (f/4 or f 1:4 in our case), again, if the range is indicated, this means that the maximum aperture depends on the focal length. This is the basic information, after it there is an indication of belonging to the top line (L) and the technologies used in this optics (IS, USM). Often you can see the Roman numerals II and III in the name - depending on the location, this is either a lens version or a technology version.

Now let's take a closer look at each abbreviation:

• E.F.(Electro-Focus) - standard mount for Canon cameras; lenses with this marking are suitable for any Canon SLR cameras.
• EF-S(Short back focus) is a type of lens mount designed for cameras with an APS-C matrix (crop). When purchasing such optics, keep in mind that they are not suitable for full-frame cameras due to the shortened rear segment.
• TS-E(Tilt Shift) and MP-E(Macro Photography) - special versions of lenses with an EF mount, but without electric focus. The first use the technology of shifting a group of lenses relative to the optical axis to correct perspective and are used mainly for photographing architecture. The second type includes only one specialized macro lens, the Canon MP-E 65 mm 1-5x Macro, which is capable of providing five times magnification without additional accessories.
• L(Luxury) - a series of lenses of improved quality with increased dust and moisture protection. Only EF lenses are marked with this letter; they are intended for professional photography and usually have a constant high aperture (for long focal lengths a variable maximum aperture is possible). Purchasing this series of optics is advisable primarily if you plan to switch to full frame; it is unlikely that you will be able to maximize their capabilities with a crop lens, but in any case there will be a noticeable increase in sharpness and a decrease in optical distortion compared to conventional lenses. Externally they differ from other lenses with a red ring around the rim.
• fisheye- a designation for a specific type of lens (fisheye), which usually comes after the maximum aperture value.
• Macro— a prefix indicating that the optics belong to the macro line. First of all, it is characterized by a reduced minimum focusing distance.
• IS(Image Stabilizer) - lenses with a built-in stabilization system based on a movable lens unit that compensates for camera movement and allows you to shoot from a more long exposures, obtaining clear images. This is a very useful technology that makes it possible to shoot without flash in dark rooms and in low light conditions. At the moment, there are several versions of stabilization technology and the newest ones make it possible to shoot at shutter speeds 4 stops longer than with conventional lenses. The presence of this technology can be determined by the Image Stabilizer inscription at the base of the lens. The technology version within one lens model is indicated in Roman numerals; the higher the number, the newer.
• USM(Ultrasonic Motor) is an ultrasonic focusing drive that allows lenses to focus faster and much quieter. Another advantage is the ability to use manual focus at any time without having to switch shooting modes. Lenses with an ultrasonic motor are marked with a gold ring, and for the L series, the inscription Ultrasonic.
• DO(Diffractive Optics) - the design of these lenses uses diffractive elements, which can significantly reduce the size of long-focus optics and almost completely eliminate chromatic aberrations. However, the high price does not allow them to become widespread, so Canon has only two models of lenses with DO. The external difference is that lenses with DO are marked with a green ring on the body.
• STM(Stepping Motor) - a stepper focusing motor used for quick and silent focusing when shooting video.

There are several other technologies that Canon, unlike its competitors, does not include in lens designations, for example, internal focusing or the use of aspherical and fluorite elements in the optical design; this data can only be found in the specifications.

A few words about lens versions. Popular versions of optics are improved from time to time and supplemented with newer technologies. Such changes are indicated by Roman numerals in the name, for example, the Canon EF 70-200 mm F 2.8 L II USM IS is the second version of the lens of the same name with an updated optical design, an improved stabilization system and slightly changed dimensions. Almost always, a newer version means better features and a higher price; whether one is worth the other is up to you to decide.

I hope this information will help you decide when choosing new optics and will give you the opportunity to evaluate the difference in price associated with the presence or absence of certain technologies.