HD Pentax-FA 43mm F/1.9 Limited

Standard prime lens • Digital era

Abbreviations

HD Multi-layer High Definition coating is applied to the surfaces of lens elements. This anti-reflection coating increases light transmission, eliminates flare and ghosting, and maintains color consistence among all lens models.
FA Autofocus lens with mechanical coupling with camera and MTF program line support. Learn more

Model history (2)

smc Pentax-FA 43mm F/1.9 LimitedPancake lensA7 - 60.45m⌀49 1997 
HD Pentax-FA 43mm F/1.9 LimitedPancake lensA7 - 60.45m⌀49 2021 

Features highlight

Fast
Body AF
8 blades
Compact
Lightweight
SP
⌀49
filters
TC

Specification

Production details:
Announced:February 2021
Production status: In production
Original name:HD PENTAX-FA 1:1.9 43mm Limited
System:Pentax K (1975)
Optical design:
Focal length:43mm
Speed:F/1.9
Maximum format:35mm full frame
Mount and Flange focal distance:Pentax K [45.5mm]
Diagonal angle of view:53.4°
Lens construction:7 elements in 6 groups
On Pentax K APS-C [1.53x] cameras:
35mm equivalent focal length:65.8mm (in terms of field of view)
35mm equivalent speed:F/2.9 (in terms of depth of field)
Diagonal angle of view:36.4°
Diaphragm mechanism:
Diaphragm type:Automatic
Aperture control:Aperture ring (Manual settings + Auto Exposure setting)
Number of blades:8 (eight)
Focusing:
Closest focusing distance:0.45m
Magnification ratio:1:8 at the closest focusing distance
Focusing modes:Autofocus, manual focus
Autofocus motor:In-camera motor
Manual focus control:Focusing ring
Focus mode selector:None; focusing mode is set from the camera
Quick-Shift Focus System (QFS):-
Shake Reduction (SR):
Built-in SR:-
Physical characteristics:
Weight:155g
Maximum diameter x Length:⌀64×27mm
Weather sealing:-
Super Protect (SP) coating:Front element
Accessories:
Filters:Screw-type 49mm
Lens hood:MH-RG49 - Screw-type round
Teleconverters:HD Pentax-DA 1.4X AF Rear Converter AW → 60.2mm F/2.7
Source of data:
Manufacturer's technical data.

Compared to the smc Pentax-FA 43mm F/1.9 Limited

  • HD Pentax-FA 43mm F/1.9 Limited
    • Advantages: 2
    • Disadvantages: 0
  • Manufacturer description #1

    Manufacturer announcement for the HD PENTAX-FA31mmF1.8 Limited, HD PENTAX-FA43mmF1.9 Limited and HD PENTAX-FA 77mmF1.8 Limited:

    2021.02.25 - TOKYO, February 25, 2021,-RICOH COMPANY, LTD and RICOH IMAGING COMPANY, LTD. are pleased to announce the launch of three HD PENTAX-FA Limited interchangeable lenses for use with PENTAX K-mount SLR cameras. Featuring the latest HD coating and a round-shaped diaphragm, these new lenses boast much-improved imaging performance to deliver distinctive, well-defined images in combination with a K-mount camera body, while sporting an attractive exterior design.

    Developed based on the FA Limited Lens series -- renowned for their meticulousness in every detail, from outstanding image rendition to high-quality, machined aluminum bodies -- these new lenses are designed to assure even better optical performance than the original Limited-series models. This is all a part of PENTAX's attempt to reach a level of performance that can't simply be measured in numerical values. Along with the distinguished qualities of the HD FA Limited series -- outstanding description of texture, fine reproduction of gradation in highlight areas, faithful reproduction of details, and natural reproduction of the bokeh (defocus) effect -- they have been treated with the PENTAX-original HD coating, which assures much higher light transmittance than conventional multi-layer coatings. They deliver sharp, clear images free of flare and ghost images, even under such demanding conditions as backlight. They also feature a completely round-shaped diaphragm to produce a natural, beautiful bokeh effect in the foreground and background.

    Main features of the HD PENTAX-FA Limited lenses (common to all three models)

    1. High-grade HD coating for exceptional image rendition

    The three new lenses are treated with the PENTAX-original HD coating.* Compared with conventional multi-layer coatings, this high-grade coating assures higher light transmittance and lower reflectance to deliver sharp, clear images free of flare and ghost images, even under such adverse lighting conditions as backlight. It elevates the imaging performance of these new lenses a further step up.

    * HD stands for High Definition.

    2. Round-shaped diaphragm for beautiful bokeh effect

    All lenses feature a completely round-shaped diaphragm, which produces a natural, beautiful bokeh (defocus) effect in the images captured, while optimizing the imaging performance of the distinctive Limited Lens-series optics contained within.

    3. Acclaimed Limited Lens-series quality for distinctive visual rendition and premium appearance

    While inheriting the design concept of the Limited Lens series, these lenses were designed through a series of mechanical and numerical evaluations, as well as human assessment of test-shooting samples, to deliver an image rendition unmatched by other models. The barrel, hood and cap are all made of high-grade aluminum, meticulously machined for an attractive appearance and beautiful texture. The HD PENTAX-FA 43mm F1.9 Limited features a mount pointer made of a Shippoyaki (cloisonné) ware. This pointer allows the user to mount the lens to a camera body as effortlessly as other Limited Lens-series models.

    4. Other features

    1. SP (Super Protect) coating is applied to the front surface of each lens to repel dust and stains.
    2. Black models are marked with a serial number starting with 0000001; silver models start with 1000001.
    3. The aperture ring has been retained so that the user can still use a variety of functions featured in K-mount film-format cameras.

    Manufacturer description #2

    Building on the long tradition of PENTAX Limited Edition lenses, RICOH COMPANY, LTD. and RICOH IMAGING COMPANY, LTD are pleased to announce three new editions to the three HD PENTAX-FA Limited lenses – featuring the original PENTAX HD coating, which now significantly enhances the lenses by minimising light reflections and ghosting.

    When PENTAX first introduced the 'Limited Series' some 25 years ago, they were developed at the time of traditional SLR technology. The first thing that caught the eye were the focal length designations. A wide-angle, with 31 mm, a standard lens with 43 mm and a portrait lens with 77 mm formed a series, offering a high standard in imaging quality and technical construction. Attention to these details make these lenses special masterpieces. The original character has stood the test of time, and again provided the foundation of the new HD PENTAX-FA Limited series:

    • HD PENTAX-FA 31mm F1.8 Limited
    • HD PENTAX-FA 43mm F1.9 Limited
    • HD PENTAX-FA 77mm F1.8 Limited

    Due to the sophisticated manufacturing process, each of these lenses is a masterpiece and was already the reason for many photographers to opt for this system in the days of analogue photography. A 35mm camera with three fixed focal lengths is a set-up that, even today in digital photography, represents a special approach and shows respect for traditional photography. PENTAX has decided to remain true to the philosophy that has been at the forefront of many new techniques since the beginning of camera production in Japan and is still the standard in modern photographic technology today.

    And so we also find in the new series focal lengths that correspond directly to the technical calculation and are not rounded to the nearest number in order to better fit into a line-up. Also, a rather unusual feature today is the mechanical aperture selection directly on the lens with the matching depth-of-field scale above the aperture ring. A small but intricate detail are the markings on the aluminium bodies of the lenses, which make it possible to change lenses without looking.

    The lens elements are treated with the multi-layer HD (High Definition) coating developed by PENTAX. Compared to conventional coatings, it offers a significantly higher light transmission with low reflection (up to 50 % compared to conventional coatings). This allows for maximum contrast and sharpness without flare and ghosting - even under difficult conditions such as backlighting. This is made possible by an exclusive PENTAX special manufacturing process, where a high-density coating is applied with high precision at the nanometre level. Which also has an extremely high hardness for superior durability.

    In addition, the front lenses are provided with the original PENTAX SP (Super Protect) Coating. A fluorine coating protects the lens surface and has a repellent effect that not only repels dust, water and grease, but also makes it easier to wipe these substances off the lens surface. It is also highly resistant to abrasion and scratching and helps to keep the lens in top condition.

    With the new HD PENTAX FA-Limited series, PENTAX follows its basic principles and stands for outstanding image reproduction with high detail fidelity with sharp and clear image reproduction, free from flare and ghosting.

    The lenses are supplied with a built-in or corresponding screw-in lens hood and an exclusive lens cap, also made of aluminium, as well as a lens bag. They are each offered in silver (serial numbers starting with 00001) and black (serial numbers starting with 10001).

    Manufacturer description #3

    A single-focus 43mm lens that faithfully captures the depth of field as seen by the human eye, while delivering a beautiful image with rich, smooth gradation transitions and a true-to-life reproduction of depth, ambience and subject texture.

    This standard lens has a 43mm focal length, which is equal to the diagonal length of a 35mm-film image area. Its unique focal length captures the image as if seen by the human eye, and produces a natural sense of depth as observed by the naked eye.

    In addition to the acclaimed optical performance of the smc PENTAX-FA 43mm F1.9 Limited — a best-seller for more than 20 years since its market launch — this lens newly features the PENTAX-original HD coating* to deliver crisp, well-defined images even under demanding conditions, and a completely round-shaped diaphragm to produce a natural, beautiful bokeh (defocus) effect. To optimize “sensibility” — one of the main design concepts of the Limited series — PENTAX paid the utmost attention even to the details that can’t simply be measured in numerical terms, to improve the imaging power of this new lens. Newly applied to the first optical element, the SP coating improves the water/grease-repellent and scratch-resistant performance, while enhancing ease of maintenance.

    To make the most of its slender lens barrel, this lens is the only model in the Limited series to feature a screw-in lens hood. Thanks to its extremely compact dimensions, it assures outstanding portability. A newly added mount pointer lets the user effortlessly and quickly mount the lens to a camera body, while accentuating the exclusive exterior appearance of the HD FA Limited series.

    Features / Specifications

    High-grade lens with superb image rendition and beautiful texture

    While inheriting the design concept of the Limited series, this lens was designed through a series of mechanical and numerical evaluations, as well as human assessment of test-shooting samples, to deliver an image rendition unmatched by other models. The barrel, hood and cap are all made of high-grade aluminum, meticulously machined for an attractive appearance and beautiful texture. It also features a mount pointer with a shippoyaki (cloisonné) finish, which lets the user effortlessly and quickly mount the lens to a camera body.

    HD coating for exceptional image rendition

    This lens is treated with PENTAX-original HD coating.* Compared with conventional multi-layer coatings, this high-grade coating assures higher light transmittance and lower reflectance to deliver sharp, clear images free of flare and ghost images, even under such adverse lighting conditions as backlight. It elevates the imaging performance a further step up.

    Round-shaped diaphragm for beautiful bokeh effect

    This lens features a completely round-shaped diaphragm, which produces a natural, beautiful bokeh (defocus) effect in the images captured, while optimizing the imaging performance of the distinctive Limited-series optics contained within.

    SP coating to repel dust and protect lens surface

    Applied to the front optical element, the PENTAX-developed SP (Super Protect) coating effectively repels water and grease to keep the lens surface free of dust, water and oily substances. This coating is also highly resistant to abrasion and scratches, keeping the lens scratch-free.

    Other features

    The black model is marked with serial numbers starting with 0000001, while the silver model starts with 1000001. The lens also features an aperture ring to make best use of the range of functions featured in K-mount film-format cameras.

    Pentax FA Limited series

    This Limited lens is not only capable of producing excellent photos, but also gives aesthetic pleasure to its owner.

    • Elegant shape and distinctive appearance;
    • Machined aluminum lens barrel, compact and lightweight design, recessed distance scale;
    • "A" setting on the aperture ring for automatic aperture control in the Programmed AE and Shutter-priority AE modes;
    • Automatic focusing using in-camera motor;
    • Support for MTF program line;
    • Exclusively designed lens hoods and caps.

    Other standard prime lenses in the Pentax K system

    Sorted by focal length and speed, in ascending order

    Pentax K mount (8)
    smc Pentax-FA 43mm F/1.9 Limited ⌀49Pancake lens 1997 Compare02
    smc Pentax-F 50mm F/1.7 ⌀49 1987 Compare04
    smc Pentax-FA 50mm F/1.7 ⌀49 1991 Compare03
    smc Pentax-F 50mm F/1.4 ⌀49Pro 1987 Compare04
    smc Pentax-FA 50mm F/1.4 ⌀49Pro 1991 Compare04
    HD Pentax-D FA* 50mm F/1.4 SDM AW ⌀72Pro 2018 Compare33
    HD Pentax-FA 50mm F/1.4 ⌀49Pro 2023 Compare02
    smc Pentax-FA 50mm F/1.4 Classic ⌀49Pro 2023 Compare02

    Lenses with similar focal length

    Sorted by manufacturer name

    Pentax K mount (3)
    smc Pentax-DA 40mm F/2.8 Limited ⌀49APS-CPancake lens 2004 Compare32
    smc Pentax-DA 40mm F/2.8 XS ⌀27APS-CPancake lens 2012 Compare32
    HD Pentax-DA 40mm F/2.8 Limited ⌀49APS-CPancake lens 2013 Compare31
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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.

    Anastigmat

    A photographic lens completely corrected for the three main optical aberrations: spherical aberration, coma, and astigmatism.

    By the mid-20th century, the vast majority of lenses were close to being anastigmatic, so most manufacturers stopped including this characteristic in lens names and/or descriptions and focused on advertising other features (anti-reflection coating, for example).

    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.

    In-camera motor

    Unable to follow the link

    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.

    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.

    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/1.9 on this lens, and cannot be adjusted.

    Automatic aperture control

    For Programmed Auto or Shutter-priority Auto shooting, set the lens aperture ring to the "A" position.

    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.