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Leica M2

35mm MF film rangefinder camera

Specification

Production details:
Announced:1958
Order No.:10300 - M2X
KOOHE / 10308 - body without lens
KOOHE / 10309 - body without lens, black finish
10331 - body with SUMMICRON 35/2
10333 - body with SUMMARON 35/2.8
KIHOO / 10335 - body with ELMAR 50/2.8
KIOOL / 10336 - body with SUMMICRON 50/2
KSOOB / 10337 - body with SUMMILUX 50/1.4
KNOOG / 10338 - body with SUMMICRON 50/2 with near-focusing range
KEZOO / 10339 - body with ELMAR 50/3.5
KOOIW - body with SUMMARIT 50/1.5
System:● Leica M (1954)
Format:
Maximum format:35mm full frame
Film type:135 cartridge-loaded film
Mount and Flange focal distance:Leica M [27.8mm]
Shutter:
Type:Focal-plane
Model:Mechanical
Speeds:1 - 1/1000 + B
Exposure:
Exposure metering:None
Exposure modes:Manual
Rangefinder and Viewfinder:
Rangefinder:Built-in, combined with viewfinder
Viewfinder:Built-in, combined with rangefinder
Finder magnification:0.72x
Actual rangefinder base:68.5mm
Effective rangefinder base:49.32mm
Bright-line frames:35mm, 50mm, 90mm
Parallax compensation:Yes
Physical characteristics:
Weight:580g
Dimensions:138x77x33.5mm
Accessories:
Body cap:IVZOO / 14056

Manufacturer description #1

From the LEICA photography magazine (1958, No. 3):

big news

On our back cover, you will see news of a Leica so new that there was no time to describe it inside this issue. But by the time you read this, your dealer will have the M-2 in stock.

Late in September, Photokina, the famous European exposition, will open. There, the Leitz factory will show other new, exciting equipment for the Leica System of photography.

announcing the great new LEICA M-2

gives you the many famous Leica features plus built-in wide angle viewing

at an irresistibly low price

features of the new Leica M-2

  • built-in luminous frame for the wide-angle 35mm lens
  • 50mm frame and 90mm frame which appear automatically as lenses are inserted
  • single-window viewfinder-rangefinder
  • automatic parallax correction throughout
  • frame selector
  • accepts bayonet-mount Leica lenses
  • fast-action advance lever
  • automatic flash synchronization
  • one shutter dial - 1/1000 second to 1 second and "Bulb"
  • release button for rewind
  • Leica-meter "MC" couples to M-2 (optional)

Manufacturer description #2

As LEICA M 3, with the following differences: Automatically superimposed image frames for 35, 50 and 90 mm focal lengths. Film counter must be returned to 0 by hand. From 1959 with self-timer. Serial No. from 926001.

Manufacturer description #3

The LEICA M 2 captures every photographic situation swiftly and surely. Its unsurpassed range- viewfinder enables even the beginner to focus easily, rapidly, and with unerring accuracy, regardless of the existing lighting conditions. The brilliantly illuminated focal frames for the 35-, 50- and 90 mm lenses are automatically parallax-compensated at all focusing distances. Inserting anyone of these three prime picture-makers into the LEICA M 2's quick-change bayonet lens-mount automatically brings the correct frame into the viewfinder, and a preselector lever is provided so that the user can determine the effect of these three focal lengths without actually changing lenses. Accurate exposure setting is ensured by the accessory LEICAMETER MC which couples to the camera's non-spinning shutter-speed selector dial.

Sturdily constructed and easy to use, the LEICA M 2 combines traditional LEITZ precision, ruggedness and reliability with almost unbelievable versatility. The VISOFLEX II, a key part of the LEICA SYSTEM offers the additional possibility of reflex groundglass focusing and viewing with focal lengths from 65- through 400 mm, and a number of LEICA lenses may actually be used with both rangefinder and reflex focusing.

From its pioneering beginning the LEICA has logically pursued and perfected three important design attributes:

1. The Direct-Vision Optical Viewfinder

The optical finder system, developed to its present high level in the LEICA M2, permits the photographer to concentrate completely upon his picture up to and through the decisive moment of exposure. The built-in focal frames for the 35-, 50- and 90 mm lenses permit simultaneous focusing and framing without changing the eye position, and these frames are automatically parallax compensated over the full focusing range to eliminate the possibility of accidentally chopped-off heads or feet.

2. The Precision Focal-Plane Shutter

The LEICA's superbly accurate focal-plane shutter permits the use of all interchangeable lens focal lengths and lens apertures without any loss of efficiency, thus providing the fundamental basis for the extremely versatile LEICA SYSTEM. It is speeded from 1 to 1/1000 sec, plus Bulb, and is provided with a delayed action self-timer plus full flash synchronization. Its rugged reliability and extreme quietness are the result of its excellent design and the tradition of LEITZ precision that goes into its careful construction.

3. Interchangeable Lenses of the Highest Quality

The exceptional image quality of interchangeable LEICA lenses is proverbial. This outstanding performance is based upon over a century of scientific optical experience combined with the most modern design and production methods which include the development of special rare-earth optical glasses in LEITZ' own research laboratories. LEICA quality control requires a testing procedure which begins with the raw glass and continues throughout the production stages until film resolving-power tests are made with each lens before shipment.

LEICA M 2 specifications

All-metal die-cast body with strap eyelets, black-grained rubberoid covering and chromium-plated metal parts. Brilliant-frame long-base range-view-finder with parallax compensated built-in frames appearing automatically when 35-, 50- or 90 mm lenses are inserted into the quick-change bayonet lens mount. Accepts lenses from 21- to 135 mm with rangefinder focusing, 65- to 400mm with VISOFLEX II reflex groundglass focusing. Focal-plane shutter speeded from 1 to 1/1000 sec. plus Bulb, with non-spinning speed selector dial coupling to LEICAMETER MC. Synchronization for flash bulbs at all speeds; for electronic-flash at 1/50th sec. Delayed-action self timer. Single-stroke rapid-advance lever for rapid film transport coupled to shutter re-set mechanism and frame-counter. Hinged flip-open back for easy film loading. Removeable baseplate interchangeable with LEICAVIT rapid-sequence device. Standard accesory shoe. (Note: LEICA cameras are usually supplied with 1/4" English tripod sockets; on special order they may also be obtained with the 3/8" Continental bushing.)

Manufacturer description #4

From the LEICA photography magazine (1958, No. 4):

Ever since the Model A was introduced in 1924, the professional photographer and the Leica have exerted a very profound influence upon each other's development. The most recent evidence of this interaction is the brand-new M 2 Leica, a pro's camera from baseplate to accessory shoe. To understand the thinking behind the M 2, it is first necessary to know a few things about the photographers whose working methods played the decisive role in its design.

The professional photojournalist has been defined as a man with seven cameras and a working wife, but this probably involves an element of exaggeration. The average professional Leicaman almost always works with a minimum of two camera bodies, and the joint use of three is far from uncommon. His basic optical outfit consists of three focal lengths: the 35mm wide-angle, the 50mm normal focus, and the 90mm long-focus lenses.

the handy wide-angle

The 35 is particularly handy under cramped conditions when it's necessary to relate subjects to their surroundings. For tightly cropped pictures, when the requirement is to isolate subjects and to simplify picture content, there's nothing like a 90. Between these include-more and crop-tight assignments, the 50 is the Leicaman's most versatile weapon. The pro, of course, also employs a wide variety of additional focal lengths, but these are specialists. On most of his assignments, most of his pictures are the work of the basic 35-50-90 team.

At Photokina 1954, professionals found most of their needs met by a completely new sort of Leica, the M 3. Overnight the M 3 became a professional mainstay, and more pros today use this camera than any other currently produced high-grade miniature.

M 3 and M 2 compared

Let us now run through the principal features which account for the M 3's tremendous professional acceptance, comparing each in turn with the new M 2.

(1) The first reason for the M 3's acclaim probably was its brilliant rangefinder (combined with its viewfinder system through a single eyepiece). This makes accurate focus not merely possible, but amazingly easy - under even the worst "available-darkness" conditions. This outstanding rangefinder has been continued in the M 2, with the addition of two depth-of-field check tabs, for f/5.6 and f/16.

(2) Next comes the unique M 3 viewfinder system in which specially illuminated focal frames for the 50, 90, and 135mm lenses appear automatically as soon as the appropriate bayonet-mounted Leica lens is locked into the M 3's rugged quick-switch lens mount. Later, this 50-90-135 bright-field framing was extended to the 35mm focal length via the "RF" Summaron which positions special optical "minifying" elements over the M 3's range- and viewfinder windows to convert its 50mm frame lines to the 35mm wide-angle field of view.

35-50-90 emerges

The M 3 was a great step forward. But a lot of photographers rarely, if ever, needed the 135mm frame. They preferred a built-in 35mm frame that would not require the Optical Viewing Unit of the "RF" Summaron. The M 2 gives it to them. Changing the viewfinder's image size to .75X (compared to the M 3's .90X) permitted a 35-50-90mm frame combination. At this image ratio, a 135mm frame would be impractically small for accurate work. But wide-anglers lose little by its absence.

(3) Third on our list of features which make the M 3 popular is automatic and continuous parallax correction. Its mechanism, through a linkage with the rangefinder, causes the M 3's focal frames to slide diagonally within the image field to eliminate framing errors at all focusing distances. (The Dual-Range Summicron's Optical Viewing Unit extends automatic parallax correction down to 19 inches!)

a first for the M 2

The same automatic parallax correction is incorporated into the M 2, accomodating, for the first time in any interchangeable lens camera (except for the M 3 with "RF" Summaron), the 35mm focal frame in addition to the 50mm and 90mm frames.

(4) Another standout M 3 feature is its surprisingly quiet focal-plane shutter which provides all speeds from 1 to 1/1000 second. The M 2 has the same shutter and the same speed selector dial. The dial does not rotate as film is advanced. This means speed can be changed before or after advancing film. The dial is slotted to accept the Leica-Meters "M," and "MC" - another big M 3 plus which has been extended into the M 2 design. Automatic flash synchronization for both conventional and electronic flash is built into both the M 3 and M 2.

unique advance lever

(5) The extremely smooth operating M 3 advance lever was a great source of M 3 enthusiasm. It operates with so little camera jar that you can actually maintain subject framing, and even refocus while operating the advance mechanism. In the M 2, the advance lever operates either with one long (about 110 degrees) or with two or more shorter strokes, and the camera has been constructed to accept both Leicavit and motor-drive baseplate accessories. The M 2 Leicavit is not yet available but should be by some time in 1959; the electric motor drive unit for sequence photography will take a bit longer.

(6) Last of the M 3 features is the flip-open back which facilitates quicker loading, swings out to expose the film gate and pressure plate for occasionally-needed cleanings. Built into the back is a film reminder dial. The flip-open back is an exclusive of the M-cameras and is an integral part of the M 2 body design.

economy in the M 2

To most pros, and many active amateurs, a Leica outfit means a minimum of two and often three bodies. So, to keep costs down on the new M 2 without giving up any essential features of the M 3 or relaxing perfectionist standards of workmanship, Leitz had just one path open: eliminate in the M 2 every M 3 feature that wasn't absolutely essential. Analysis revealed only three features that the designers would consider scrapping - these are:

(1) The automatically resetting frame counter. In-stead of this the M 2 has a manually-set counter that is concentric with the M 2 release button.

(2) The built-in self-timer. The M 2 has none.

(3) The advance/rewind lever of the M 3 has been changed in the M 2 to a simple push-button device.

Another item appears on the M 2 as a sort of bonus feature. Although not absolutely essential, the focal pre-selector switch on the M 3 is a great convenience to many. It is carried over to the M 2 for previewing of the subject through the frames for the 35mm, 50mm, and 90mm frames.

From the editor

A less expensive alternative to the M3. It has most of the features of that model. It does, however, differ in some minor respects:

  • Built-in, bright-line frames for 35mm, 50mm and 90mm lenses.
  • Viewfinder magnification reduced to 0.72x (to accomodate 35mm frame);
  • Depth of field indicator in viewfinder;
  • Manually-reset automatic exposure counter;
  • May be used with a Leicavit Rapid Winder base-plate without modification (The Leicavit cannot be used on the M3);
  • Self-timer built-in from No. 1,004,151 but absent in a variation of the M2 called M2X.

Silver chrome finish, but a small number of bodies were in black.

Special limited editions (1)

Similar cameras (13)

35mm full frame • Manual focus • Film • Rangefinder • Leica M mount

Model Shutter Metering Modes Year
Cosina Voigtlander BESSA-R2 M, 1/2000 TTL • WA M 2002
Cosina Voigtlander BESSA-R2A E, 1/2000 TTL • WA AM 2004
Cosina Voigtlander BESSA-R2M M, 1/2000 TTL • WA M 2006
Cosina Voigtlander BESSA-R3A E, 1/2000 TTL • WA AM 2004
Cosina Voigtlander BESSA-R3M M, 1/2000 TTL • WA M 2006
Cosina Voigtlander BESSA-R4A E, 1/2000 TTL • WA AM 2006
Cosina Voigtlander BESSA-R4M M, 1/2000 TTL • WA M 2006
Cosina Voigtlander BESSA-T M, 1/2000 TTL • WA M 2001
Konica HEXAR RF E, 1/4000 TTL • WA AM 1999
Leica CL
aka LEITZ minolta CL		 M, 1/1000 TTL • WA M 1973
Minolta CLE E, 1/1000 TTL • WA AM 1980
Rollei 35 RF M, 1/2000 TTL • WA M 2002
Zeiss Ikon E, 1/2000 TTL • WA AM 2004
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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.

IVZOO / 14056

Protection cap, for camera body with LEICA M bayonet mount.

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/ 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.