Canon EF 400mm F/2.8L II USM

Super telephoto prime lens • Film era • Discontinued

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Abbreviations

EF The lens is designed for Canon EOS 35mm SLR cameras but can be also used on Canon EOS APS-C digital SLR cameras.
L Professional lens with high quality optics and robust build. Meets the highest standards and provides excellent performance and flawless image quality unachievable with traditional optical technologies.
II Second generation.
USM The lens is equipped with Ultrasonic Motor.

Model history (5)

Canon EF 400mm F/2.8L USMA11 - 94.00m-- 1991 
Canon EF 400mm F/2.8L II USMA11 - 94.00m-- 1996 
Canon EF 400mm F/2.8L IS USMA17 - 133.00m-- 1999 
Canon EF 400mm F/2.8L IS II USMA16 - 122.70m-- 2011 
Canon EF 400mm F/2.8L IS III USMA17 - 132.50m-- 2018 

Features highlight

Fast
1
FL
2
UD
IF
RT USM
FTM
Focus limiter
8 blades
Drop-in filters
TC

Specification

Production details:
Announced:March 1996
Production status: Discontinued
Original name:CANON LENS EF 400mm 1:2.8 L II ULTRASONIC
System:Canon EOS (1987)
Optical design:
Focal length:400mm
Speed:F/2.8
Maximum format:35mm full frame
Mount and Flange focal distance:Canon EF [44mm]
Diagonal angle of view:6.2°
Lens construction:11 elements in 9 groups
1 FL, 2 UD
Internal focusing (IF)
On Canon EOS APS-C [1.59x] cameras:
35mm equivalent focal length:636mm (in terms of field of view)
35mm equivalent speed:F/4.5 (in terms of depth of field)
Diagonal angle of view:3.9°
Diaphragm mechanism:
Diaphragm type:Automatic
Aperture control:None; the aperture is controlled from the camera
Number of blades:8 (eight)
Focusing:
Closest focusing distance:4m
Magnification ratio:1:9.1 at the closest focusing distance
Focusing modes:Autofocus, manual focus
Autofocus motor:Ring-type Ultrasonic Motor
Manual focus control:Focusing ring
Focus mode selector:AF - MF
Full-Time Manual Focus (FTM):Yes
Focusing distance range limiter:4-;4-9.5;9.5-
Image Stabilizer (IS):
Built-in IS:-
Physical characteristics:
Weight:5910g
Maximum diameter x Length:⌀167×348mm
Weather sealing:-
Fluorine coating:-
Accessories:
Filters:Removable front filters are not accepted
Additional features:Drop-in filter holder (48mm)
Lens hood:ET-161BII - Clamp-on round
Teleconverters:Canon Extender EF 1.4X II → 560mm F/3.9
Canon Extender EF 1.4X III → 560mm F/3.9
Canon Extender EF 2X II → 800mm F/5.6
Canon Extender EF 2X III → 800mm F/5.6
Source of data:
Manufacturer's technical data.

Compared to the Canon EF 400mm F/2.8L USM

  • Canon EF 400mm F/2.8L II USM
    • Advantages: 1
    • Disadvantages: 0
  • Manufacturer description #1

    LAS VEGAS, NV., February 22, 1996 -- Canon U.S.A., Inc. is introducing four new EF lenses at this year's PMA Trade Show and Convention, expanding the total number in the EF line to 50, the widest selection of autofocus lenses available in any 35mm SLR camera system. They include the Canon EF 17-35mm f/2.8L USM, 135mm f/2L USM, 180mm f/3.5L Macro and 400mm f/2.8L II USM. The new L-Series lenses are designed specifically for professional and advanced amateur photographers and offer an extended selection of fast, and extremely sharp focal lengths.

    "Canon is committed to offering photographers the widest selection of high quality optics in the industry," said Ted Ando, director and general manager of Canon's Camera Division."Canon will continue to introduce new products and improve existing ones based on the needs and requests of our customers," Mr. Ando added.

    EF 400mm f/2.8L II USM Reflects Canon's Commitment to Improvement

    The new EF 400mm f/2.8L II USM telephoto lens offers improved optical performance compared to its predecessor by incorporating a fluorite element in Group 2 and UD-glass elements in Groups 3 and 5. The combination of these improvements has substantially minimized residual chromatic aberrations such as blur and flare, while enhancing color reproduction.

    While improving the performance of the lens, Canon was also able to reduce its overall weight by 19 ounces. The design of its predecessor required two glass elements to protect against thermal shock. The fluorite element, which is more resistant to thermal shock than UD-glass elements, is positioned behind the protective glass -- thus eliminating one protective glass element and providing photographers with a lighter lens.

    As with other Canon EF-Series lenses, the 400mm f/2.8L II USM incorporates Canon's exclusive ring-type Ultrasonic Motor (USM) technology with internal focusing. This provides photographers with a lens which offers silent, high-speed autofocusing and a full-time electronic manual focus override for added creative control. M. FOCUS speed allows the electronic focusing ring's rotating angle to be set at half, full, or double speed.

    As with other Canon EF fixed-focal length telephoto lenses, the EF 400mm f/2.8L USM is compatible with EF 1.4x and 2x extenders.

    Large Lens Inventory Meets All Shooting Requirements

    Canon offers professional and advanced photographers the widest selection of autofocus lenses available in any 35mm SLR System. Currently offering 50 lenses for use with Canon EOS System cameras, the complete line ranges from 14mm ultra-wide angle to 1200mm Super Telephoto for all-purpose photography, macro lenses for nature and outdoor work, Tilt-Shift lenses for architecture and studio photography, and high-speed zooms for photojournalism. Canon lenses offer features and performance to meet every photographer's requirement.

    Canon's white-barreled super-telephoto L- Series lenses are continuously extolled by professional photographers around the world as being super-high-performance lenses with unrivaled sharpness. The key to this performance is the complete elimination of the secondary spectrum through liberal use of fluorite and UD (Ultra-Low Dispersion) glass lenses.

    A large selection of Canon L-Series EF super telephoto lenses combine superior optical performance and fast maximum aperture with the ruggedness professionals need. From the 200mm f/1.8L to the 600mm f/4L, Canon L-Series telephotos are used in all areas of photography. Canon's reputation for quality as a leader in optics has given professional photographers the confidence and competitive edge they need to produce some of the world's most exciting images.

    The availability of the new EF lenses are as follows:

    • EF 17-35mm f/2.8L USM (April)
    • EF 135mm f/2L USM (March)
    • EF 180mm f/3.5L USM (April)
    • EF 400mm f/2.8L II USM (March)

    Manufacturer description #2

    This super telephoto lens is useful for a wide variety of shooting situations, including fashion photography where its large maximum aperture permits beautiful background blur, and sports photography both indoors and outdoors under nighttime illumination. Secondary spectrum is effectively eliminated by one Fluorite and two UD elements. This lens delivers high resolution and contrast for excellent image qulaity with little chromatic aberratiion at the boundaries of the subject. Compared to the former model, the weight of the lens has been substantially decreased by reducing the protective glass (due to the use of strong Fluorite) and by slimming the lens barrel. With a ring USM and internal focusing, autofocus response is outstanding. Full-time manual focus (with three sensitivity settings), preset focusing, and other functions normally found on Canon super telephoto lenses are also provided. Attaching Extenders EF1.4X or 2X permits super zoom AF photography at 560mm f/4 and 800mm f/5.6, respectively.

    Alternatives among lenses that are part of a system

    Sorted by focal length and speed, in ascending order

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    Chromatic aberration

    There are two kinds of chromatic aberration: longitudinal and lateral. Longitudinal chromatic aberration is a variation in location of the image plane with changes in wave lengths. It produces the image point surrounded by different colors which result in a blurred image in black-and-white pictures. Lateral chromatic aberration is a variation in image size or magnification with wave length. This aberration does not appear at axial image points but toward the surrounding area, proportional to the distance from the center of the image field. Stopping down the lens has only a limited effect on these aberrations.

    Spherical aberration

    Spherical aberration is caused because the lens is round and the film or image sensor is flat. Light entering the edge of the lens is more severely refracted than light entering the center of the lens. This results in a blurred image, and also causes flare (non-image forming internal reflections). Stopping down the lens minimizes spherical aberration and flare, but introduces diffraction.

    Astigmatism

    Astigmatism in a lens causes a point in the subject to be reproduced as a line in the image. The effect becomes worse towards the corner of the image. Stopping down the lens has very little effect.

    Coma

    Coma in a lens causes a circular shape in the subject to be reproduced as an oval shape in the image. Stopping down the lens has almost no effect.

    Curvature of field

    Curvature of field is the inability of a lens to produce a flat image of a flat subject. The image is formed instead on a curved surface. If the center of the image is in focus, the edges are out of focus and vice versa. Stopping down the lens has a limited effect.

    Distortion

    Distortion is the inability of a lens to capture lines as straight across the entire image area. Barrel distortion causes straight lines at the edges of the frame to bow toward the center of the image, producing a barrel shape. Pincushion distortion causes straight lines at the edges of the frame to curve in toward the lens axis. Distortion, whether barrel or pincushion type, is caused by differences in magnification; stopping down the lens has no effect at all.

    The term "distortion" is also sometimes used instead of the term "aberration". In this case, other types of optical aberrations may also be meant, not necessarily geometric distortion.

    Diffraction

    Classically, light is thought of as always traveling in straight lines, but in reality, light waves tend to bend around nearby barriers, spreading out in the process. This phenomenon is known as diffraction and occurs when a light wave passes by a corner or through an opening. Diffraction plays a paramount role in limiting the resolving power of any lens.

    Doublet

    Doublet is a lens design comprised of two elements grouped together. Sometimes the two elements are cemented together, and other times they are separated by an air gap. Examples of this type of lens include achromatic close-up lenses.

    Dynamic range

    Dynamic range is the maximum range of tones, from darkest shadows to brightest highlights, that can be produced by a device or perceived in an image. Also called tonal range.

    Resolving power

    Resolving power is the ability of a lens, photographic emulsion or imaging sensor to distinguish fine detail. Resolving power is expressed in terms of lines per millimeter that are distinctly recorded in the final image.

    Vignetting

    Vignetting is the darkening of the corners of an image relative to the center of the image. There are three types of vignetting: optical, mechanical, and natural vignetting.

    Optical vignetting is caused by the physical dimensions of a multi-element lens. Rear elements are shaded by elements in front of them, which reduces the effective lens opening for off-axis incident light. The result is a gradual decrease of the light intensity towards the image periphery. Optical vignetting is sensitive to the aperture and can be completely cured by stopping down the lens. Two or three stops are usually sufficient.

    Mechanical vignetting occurs when light beams are partially blocked by external objects such as thick or stacked filters, secondary lenses, and improper lens hoods.

    Natural vignetting (also known as natural illumination falloff) is not due to the blocking of light rays. The falloff is approximated by the "cosine fourth" law of illumination falloff. Wide-angle rangefinder designs are particularly prone to natural vignetting. Stopping down the lens cannot cure it.

    Flare

    Bright shapes or lack of contrast caused when light is scattered by the surface of the lens or reflected off the interior surfaces of the lens barrel. This is most often seen when the lens is pointed toward the sun or another bright light source. Flare can be minimized by using anti-reflection coatings, light baffles, or a lens hood.

    Ghosting

    Glowing patches of light that appear in a photograph due to lens flare.

    Retrofocus design

    Design with negative lens group(s) positioned in front of the diaphragm and positive lens group(s) positioned at the rear of the diaphragm. This provides a short focal length with a long back focus or lens-to-film distance, allowing for movement of the reflex mirror in SLR cameras. Sometimes called an inverted telephoto lens.

    Rectilinear design

    Design that does not introduce significant distortion, especially ultra-wide angle lenses that preserve straight lines and do not curve them (unlike a fisheye lens, for instance).

    Focus shift

    A change in the position of the plane of optimal focus, generally due to a change in focal length when using a zoom lens, and in some lenses, with a change in aperture.

    Transmittance

    The amount of light that passes through a lens without being either absorbed by the glass or being reflected by glass/air surfaces.

    Modulation Transfer Function (MTF)

    When optical designers attempt to compare the performance of optical systems, a commonly used measure is the modulation transfer function (MTF).

    The components of MTF are:

    The MTF of a lens is a measurement of its ability to transfer contrast at a particular resolution from the object to the image. In other words, MTF is a way to incorporate resolution and contrast into a single specification.

    Knowing the MTF curves of each photographic lens and camera sensor within a system allows a designer to make the appropriate selection when optimizing for a particular resolution.

    Veiling glare

    Lens flare that causes loss of contrast over part or all of the image.

    Anti-reflection coating

    When light enters or exits an uncoated lens approximately 5% of the light is reflected back at each lens-air boundary due to the difference in refractive index. This reflected light causes flare and ghosting, which results in deterioration of image quality. To counter this, a vapor-deposited coating that reduces light reflection is applied to the lens surface. Early coatings consisted of a single thin film with the correct refractive index differences to cancel out reflections. Multi-layer coatings, introduced in the early 1970s, are made up of several such films.

    Benefits of anti-reflection coating:

    Circular fisheye

    Produces a 180° angle of view in all directions (horizontal, vertical and diagonal).

    The image circle of the lens is inscribed in the image frame.

    Diagonal (full-frame) fisheye

    Covers the entire image frame. For this reason diagonal fisheye lenses are often called full-frame fisheyes.

    Extension ring

    Extension rings can be used singly or in combination to vary the reproduction ratio of lenses. They are mounted between the camera body and the lens. As a rule, the effect becomes stronger the shorter the focal length of the lens in use, and the longer the focal length of the extension ring.

    View camera

    A large-format camera with a ground-glass viewfinder at the image plane for viewing and focusing. The photographer must stick his head under a cloth hood in order to see the image projected on the ground glass. Because of their 4x5-inch (or larger) negatives, these cameras can produce extremely high-quality results. View cameras also usually support movements.

    135 cartridge-loaded film

    43.27 24 36
    • Introduced: 1934
    • Frame size: 36 × 24mm
    • Aspect ratio: 3:2
    • Diagonal: 43.27mm
    • Area: 864mm2
    • Double perforated
    • 8 perforations per frame

    120 roll film

    71.22 44 56
    • Introduced: 1901
    • Frame size: 56 × 44mm
    • Aspect ratio: 11:14
    • Diagonal: 71.22mm
    • Area: 2464mm2
    • Unperforated

    120 roll film

    79.2 56 56
    • Introduced: 1901
    • Frame size: 56 × 56mm
    • Aspect ratio: 1:1
    • Diagonal: 79.2mm
    • Area: 3136mm2
    • Unperforated

    120 roll film

    89.64 56 70
    • Introduced: 1901
    • Frame size: 70 × 56mm
    • Aspect ratio: 5:4
    • Diagonal: 89.64mm
    • Area: 3920mm2
    • Unperforated

    220 roll film

    71.22 44 56
    • Introduced: 1965
    • Frame size: 56 × 44mm
    • Aspect ratio: 11:14
    • Diagonal: 71.22mm
    • Area: 2464mm2
    • Unperforated
    • Double the length of 120 roll film

    220 roll film

    79.2 56 56
    • Introduced: 1965
    • Frame size: 56 × 56mm
    • Aspect ratio: 1:1
    • Diagonal: 79.2mm
    • Area: 3136mm2
    • Unperforated
    • Double the length of 120 roll film

    220 roll film

    89.64 56 70
    • Introduced: 1965
    • Frame size: 70 × 56mm
    • Aspect ratio: 5:4
    • Diagonal: 89.64mm
    • Area: 3920mm2
    • Unperforated
    • Double the length of 120 roll film

    Shutter speed ring with "F" setting

    The "F" setting disengages the leaf shutter and is set when using only the focal plane shutter in the camera body.

    Catch for disengaging cross-coupling

    The shutter and diaphragm settings are cross-coupled so that the diaphragm opens to a corresponding degree when faster shutter speeds are selected. The cross-coupling can be disengaged at the press of a catch.

    Cross-coupling button

    With the cross-coupling button depressed speed/aperture combinations can be altered without changing the Exposure Value setting.

    M & X sync

    The shutter is fully synchronized for M- and X-settings so that you can work with flash at all shutter speeds.

    In M-sync, the shutter closes the flash-firing circuit slightly before it is fully open to catch the flash at maximum intensity. The M-setting is used for Class M flash bulbs.

    In X-sync, the flash takes place when the shutter is fully opened. The X-setting is used for electronic flash.

    X sync

    The shutter is fully synchronized for X-setting so that you can work with flash at all shutter speeds.

    In X-sync, the flash takes place when the shutter is fully opened. The X-setting is used for electronic flash.

    Ring-type Ultrasonic Motor

    Focusing distance range limiter

    The lens features focusing distance range limiter which allows to choose between the following focusing distance ranges:

    4m - ∞Full range of focusing distances.
    4m - 9.5mRange of focusing distances suitable for shooting nearby subjects.
    9.5m - ∞Range of focusing distances suitable for shooting distant subjects.

    By setting the suitable focusing distance range, the actual autofocusing time can be shorter.

    AF - MF

    AFAutofocus mode.
    MFManual focus mode.

    Drop-in filter holder

    A drop-in filter holder with a neutral filter comes with the lens. The holder accepts 48mm filters. The filter holder must be always in place because the filter is a part of the lens optical system.

    Aspherical elements

    Aspherical elements (ASPH, XA, XGM) are used in wide-angle lenses for correction of distortion and in large-aperture lenses for correction of spherical aberration, astigmatism and coma, thus ensuring excellent sharpness and contrast even at fully open aperture. The effect of the aspherical element is determined by its position within the optical formula: the more the aspherical element moves away from the aperture stop, the more it influences distortion; close to the aperture stop it can be particularly used to correct spherical aberration. Aspherical element can substitute one or several regular spherical elements to achieve similar or better optical results, which allows to develop more compact and lightweight lenses.

    Use of aspherical elements has its downsides: it leads to non-uniform rendering of out-of-focus highlights. This effect usually appears as "onion-like" texture of concentric rings or "wooly-like" texture and is caused by very slight defects in the surface of aspherical element. It is difficult to predict such effect, but usually it occurs when the highlights are small enough and far enough out of focus.

    Low dispersion elements

    Low dispersion elements (ED, LD, SD, UD etc) minimize chromatic aberrations and ensure excellent sharpness and contrast even at fully open aperture. This type of glass exhibits low refractive index, low dispersion, and exceptional partial dispersion characteristics compared to standard optical glass. Two lenses made of low dispersion glass offer almost the same performance as one fluorite lens.

    Low dispersion elements

    Low dispersion elements (ED, LD, SD, UD etc) minimize chromatic aberrations and ensure excellent sharpness and contrast even at fully open aperture. This type of glass exhibits low refractive index, low dispersion, and exceptional partial dispersion characteristics compared to standard optical glass. Two lenses made of low dispersion glass offer almost the same performance as one fluorite lens.

    Canon's Super UD, Nikon's Super ED, Pentax' Super ED, Sigma's FLD ("F" Low Dispersion), Sony' Super ED and Tamron's XLD glasses are the highest level low dispersion glasses available with extremely high light transmission. These optical glasses have a performance equal to fluorite glass.

    High-refraction low-dispersion elements

    High-refraction low-dispersion elements (HLD) minimize chromatic aberrations and ensure excellent sharpness and contrast even at fully open aperture.

    High Index, High Dispersion elements

    High Index, High Dispersion elements (HID) minimize chromatic aberrations and ensure excellent sharpness and contrast even at fully open aperture.

    Anomalous partial dispersion elements

    Anomalous partial dispersion elements (AD) minimize chromatic aberrations and ensure excellent sharpness and contrast even at fully open aperture.

    Fluorite elements

    Synthetic fluorite elements (FL) minimize chromatic aberrations and ensure excellent sharpness and contrast even at fully open aperture. Compared with optical glass, fluorite lenses have a considerably lower refraction index, low dispersion and extraordinary partial dispersion, and high transmission of infrared and ultraviolet light. They are also significantly lighter than optical glass.

    According to Nikon, fluorite easily cracks and is sensitive to temperature changes that can adversely affect focusing by altering the lens' refractive index. To avoid this, Canon, as the manufacturer most widely using fluorite in its telephoto lenses, never uses fluorite in the front and rear lens elements, and the white coating is applied to the lens barrels to reflect light and prevent the lens from overheating.

    Short-wavelength refractive elements

    High and specialized-dispersion elements (SR) refract light with wavelengths shorter than that of blue to achieve highly precise chromatic aberration compensation. This technology also results in smaller and lighter lenses.

    Blue Spectrum Refractive Optics

    Organic Blue Spectrum Refractive Optics material (BR Optics) placed between convex and concave elements made from conventional optical glass provides more efficient correction of longitudinal chromatic aberrations in comparison with conventional technology.

    Diffraction elements

    Diffraction elements (DO, PF) cancel chromatic aberrations at various wavelengths. This technology results in smaller and lighter lenses in comparison with traditional designs with no compromise in image quality.

    High refractive index elements

    High refractive index elements (HR, HRI, XR etc) minimize field curvature and spherical aberration. High refractive index element can substitute one or several regular elements to achieve similar or better optical results, which allows to develop more compact and lightweight lenses.

    Apodization element

    Apodization element (APD) is in fact a radial gradient filter. It practically does not change the characteristics of light beam passing through its central part but absorbs the light at the periphery. It sort of softens the edges of the aperture making the transition from foreground to background zone very smooth and results in very attractive, natural looking and silky smooth bokeh.

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    You are already on the page dedicated to this lens.

    Cannot perform comparison

    Cannot compare the lens to itself.

    Image stabilizer

    A technology used for reducing or even eliminating the effects of camera shake. Gyro sensors inside the lens detect camera shake and pass the data to a microcomputer. Then an image stabilization group of elements controlled by the microcomputer moves inside the lens and compensates camera shake in order to keep the image static on the imaging sensor or film.

    The technology allows to increase the shutter speed by several stops and shoot handheld in such lighting conditions and at such focal lengths where without image stabilizer you have to use tripod, decrease the shutter speed and/or increase the ISO setting which can lead to blurry and noisy images.

    Original name

    Lens name as indicated on the lens barrel (usually on the front ring). With lenses from film era, may vary slightly from batch to batch.

    Original name

    Camera name as indicated on the camera body.

    Format

    Format refers to the shape and size of film or image sensor.

    35mm is the common name of the 36x24mm film format or image sensor format. It has an aspect ratio of 3:2, and a diagonal measurement of approximately 43mm. The name originates with the total width of the 135 film which was the primary medium of the format prior to the invention of the full frame digital SLR. Historically the 35mm format was sometimes called small format to distinguish it from the medium and large formats.

    APS-C is an image sensor format approximately equivalent in size to the film negatives of 25.1x16.7mm with an aspect ratio of 3:2.

    Medium format is a film format or image sensor format larger than 36x24mm (35mm) but smaller than 4x5in (large format).

    Angle of view

    Angle of view describes the angular extent of a given scene that is imaged by a camera. It is used interchangeably with the more general term field of view.

    As the focal length changes, the angle of view also changes. The shorter the focal length (eg 18mm), the wider the angle of view. Conversely, the longer the focal length (eg 55mm), the smaller the angle of view.

    A camera's angle of view depends not only on the lens, but also on the sensor. Imaging sensors are sometimes smaller than 35mm film frame, and this causes the lens to have a narrower angle of view than with 35mm film, by a certain factor for each sensor (called the crop factor).

    This website does not use the angles of view provided by lens manufacturers, but calculates them automatically by the following formula: 114.6 * arctan (21.622 / CF * FL),

    where:

    CF – crop-factor of a sensor,
    FL – focal length of a lens.

    Mount

    A lens mount is an interface — mechanical and often also electrical — between a camera body and a lens.

    A lens mount may be a screw-threaded type, a bayonet-type, or a breech-lock type. Modern camera lens mounts are of the bayonet type, because the bayonet mechanism precisely aligns mechanical and electrical features between lens and body, unlike screw-threaded mounts.

    Lens mounts of competing manufacturers (Canon, Nikon, Pentax, Sony etc.) are always incompatible. In addition to the mechanical and electrical interface variations, the flange focal distance can also be different.

    The flange focal distance (FFD) is the distance from the mechanical rear end surface of the lens mount to the focal plane.

    Lens construction

    Lens construction – a specific arrangement of elements and groups that make up the optical design, including type and size of elements, type of used materials etc.

    Element - an individual piece of glass which makes up one component of a photographic lens. Photographic lenses are nearly always built up of multiple such elements.

    Group – a cemented together pieces of glass which form a single unit or an individual piece of glass. The advantage is that there is no glass-air surfaces between cemented together pieces of glass, which reduces reflections.

    Focal length

    The focal length is the factor that determines the size of the image reproduced on the focal plane, picture angle which covers the area of the subject to be photographed, depth of field, etc.

    Speed

    The largest opening or stop at which a lens can be used is referred to as the speed of the lens. The larger the maximum aperture is, the faster the lens is considered to be. Lenses that offer a large maximum aperture are commonly referred to as fast lenses, and lenses with smaller maximum aperture are regarded as slow.

    In low-light situations, having a wider maximum aperture means that you can shoot at a faster shutter speed or work at a lower ISO, or both.

    Closest focusing distance

    The minimum distance from the focal plane (film or sensor) to the subject where the lens is still able to focus.

    Closest working distance

    The distance from the front edge of the lens to the subject at the maximum magnification.

    Magnification ratio

    Determines how large the subject will appear in the final image. Magnification is expressed as a ratio. For example, a magnification ratio of 1:1 means that the image of the subject formed on the film or sensor will be the same size as the subject in real life. For this reason, a 1:1 ratio is often called "life-size".

    Manual focus override in autofocus mode

    Allows to perform final focusing manually after the camera has locked the focus automatically. Note that you don't have to switch camera and/or lens to manual focus mode.

    Manual focus override in autofocus mode

    Allows to perform final focusing manually after the camera has locked the focus automatically. Note that you don't have to switch camera and/or lens to manual focus mode.

    Electronic manual focus override is performed in the following way: half-press the shutter button, wait until the camera has finished the autofocusing and then focus manually without releasing the shutter button using the focusing ring.

    Fixed focus

    There is no helicoid in this lens and everything is in focus from the closest focusing distance to infinity.

    Internal focusing (IF)

    Conventional lenses employ an all-group shifting system, in which all lens elements shift during focusing. The IF system, however, shifts only part of the optics during focusing. The advantages of the IF system are:

    Manual diaphragm

    The diaphragm must be stopped down manually by rotating the detent aperture ring.

    Preset diaphragm

    The lens has two rings, one is for pre-setting, while the other is for normal diaphragm adjustment. The first ring must be set at the desired aperture, the second ring then should be fully opened for focusing, and turned back for stop down to the pre-set value.

    Semi-automatic diaphragm

    The lens features spring mechanism in the diaphragm, triggered by the shutter release, which stops down the diaphragm to the pre-set value. The spring needs to be reset manually after each exposure to re-open diaphragm to its maximum value.

    Automatic diaphragm

    The camera automatically closes the diaphragm down during the shutter operation. On completion of the exposure, the diaphragm re-opens to its maximum value.

    Fixed diaphragm

    The aperture setting is fixed at F/2.8 on this lens, and cannot be adjusted.

    Number of blades

    As a general rule, the more blades that are used to create the aperture opening in the lens, the rounder the out-of-focus highlights will be.

    Some lenses are designed with curved diaphragm blades, so the roundness of the aperture comes not from the number of blades, but from their shape. However, the fewer blades the diaphragm has, the more difficult it is to form a circle, regardless of rounded edges.

    At maximum aperture, the opening will be circular regardless of the number of blades.

    Weight

    Excluding case or pouch, caps and other detachable accessories (lens hood, close-up adapter, tripod adapter etc.).

    Maximum diameter x Length

    Excluding case or pouch, caps and other detachable accessories (lens hood, close-up adapter, tripod adapter etc.).

    For lenses with collapsible design, the length is indicated for the working (retracted) state.

    Weather sealing

    A rubber material which is inserted in between each externally exposed part (manual focus and zoom rings, buttons, switch panels etc.) to ensure it is properly sealed against dust and moisture.

    Lenses that accept front mounted filters typically do not have gaskets behind the filter mount. It is recommended to use a filter for complete weather resistance when desired.

    Fluorine coating

    Helps keep lenses clean by reducing the possibility of dust and dirt adhering to the lens and by facilitating cleaning should the need arise. Applied to the outer surface of the front and/or rear lens elements over multi-coatings.

    Filters

    Lens filters are accessories that can protect lenses from dirt and damage, enhance colors, minimize glare and reflections, and add creative effects to images.

    Lens hood

    A lens hood or lens shade is a device used on the end of a lens to block the sun or other light source in order to prevent glare and lens flare. Flare occurs when stray light strikes the front element of a lens and then bounces around within the lens. This stray light often comes from very bright light sources, such as the sun, bright studio lights, or a bright white background.

    The geometry of the lens hood can vary from a plain cylindrical or conical section to a more complex shape, sometimes called a petal, tulip, or flower hood. This allows the lens hood to block stray light with the higher portions of the lens hood, while allowing more light into the corners of the image through the lowered portions of the hood.

    Lens hoods are more prominent in long focus lenses because they have a smaller viewing angle than that of wide-angle lenses. For wide angle lenses, the length of the hood cannot be as long as those for telephoto lenses, as a longer hood would enter the wider field of view of the lens.

    Lens hoods are often designed to fit onto the matching lens facing either forward, for normal use, or backwards, so that the hood may be stored with the lens without occupying much additional space. In addition, lens hoods can offer some degree of physical protection for the lens due to the hood extending farther than the lens itself.

    Teleconverters

    Teleconverters increase the effective focal length of lenses. They also usually maintain the closest focusing distance of lenses, thus increasing the magnification significantly. A lens combined with a teleconverter is normally smaller, lighter and cheaper than a "direct" telephoto lens of the same focal length and speed.

    Teleconverters are a convenient way of enhancing telephoto capability, but it comes at a cost − reduced maximum aperture. Also, since teleconverters magnify every detail in the image, they logically also magnify residual aberrations of the lens.

    Lens caps

    Scratched lens surfaces can spoil the definition and contrast of even the finest lenses. Lens covers are the best and most inexpensive protection available against dust, moisture and abrasion. Safeguard lens elements - both front and rear - whenever the lens is not in use.