Exakta 66

Medium format MF film SLR camera • Collectible

Specification

Production details:
Announced:1953
Production type:Small-batch production
System: Exakta 66 (vertical) (1953)
Format:
Maximum format:Medium format 6x6
Film type:120 roll film
Mount and Flange focal distance:Exakta 66 (vertical)
Shutter:
Type:Focal-plane
Model:Mechanical
Speeds:12 - 1/1000 + B, T
Exposure:
Exposure metering:None
Exposure modes:Manual
Physical characteristics:
Weight:<No data>
Dimensions:139.7x114.3x114.3mm

Manufacturer description #1

From the EXAKTA Magazine (Vol. 2, No. 2, 1953):

The eagerly-awaited, new 2 1/4 x 2 1/4-inch (6x6-cm.) Exakta probably will available the United States before the end of this year. It is unnecessary to tell Exakta owners what the advantages of such a camera are and how important the new Exakta will be to photographers all over the world. Ihagee has spent many years designing and perfecting this great addition to the single-lens reflex line, and reports from Europe about the camera already have stirred up a beehive of interest. For this reason, we wish to emphasize that the camera is not yet available and that delivery date is indefinite.

The new Exakta will be called the 66. The price has not yet been established, but it will be about $300 with the standard lens. This will be the redesigned 80-mm., Zeiss Jena Tessar with built-in preset diaphragm mechanism and sunshade.

The 66 takes 12 pictures, 2 1/4 x 2 1/4 inches in size, on 120 rollfilm. The shape and design are radically different from the experimental model of this camera, which was introduced in 1939.

The body is now roughly square in shape, measuring 5 1/2 inches high, 4 1/2 inches wide and 4 1/2 inches deep (without lens). All important operating mechanisms are located on the right side.

The two-curtain cloth shutter and two speed setting knobs are similar to those of the 35-mm. Exakta models. The two knobs also are similar to those of the miniature Exakta and provide 29 speed settings ranging from 1/1000 of a second to 12 seconds for instantaneous release. Delayed action exposures can be made up to a speed of 6 seconds.

The new Exakta has an automatic film-transport, shutter-cocking mechanism that operates from the first frame. An ingenious indicator on the camera back indicates that the first frame has been reached. The film-transport mechanism locks until the exposure has been made. Then the film can be advanced only enough to bring the next frame into position back of the lens. The combination ratchet-type film-transport winder is given a half-turn to advance the film and frame counter and to cock the shutter. Double exposures are possible.

The shutter release is on the right side of the camera on the front of the body next to the lens. It has a safety lock on it.

The interchangeable 80-mm. Tessar, in addition to the preset diaphragm mechanism, has distance scales in both feet and meters. Additional lenses will be available ranging in focal length from 56 to 400 mm. Several wide-angles, f/3.5 Primotars of 85, 165 and 180 mm. and f/5.5 Meyer Tele-Megors of 150, 180, 250 and 400 mm. will be available.

The back of the camera is removable and can be locked with a swinging lever. Interchangeable backs will be available in the future. An indentation in the back affords a fingerhold for grasping and steadying the camera. A folding metal strip below the lens can be used for steadying the camera or balancing it when it is placed on a flat surface.

Built-in flash synchronization is provided by means of a single socket on the left, top side of the camera. The same socket is used for both regular and electronic flash and an adjustable scale permits the time delay to be altered within the 0-20 millisecond range.

The folding viewfinder is removable for interchange with other viewfinders which will be available. The camera will come with the standard viewfinder which can be used at waist level or, if the front window is opened, as an eye-level, sports finder. An eye-level Penta Prism will be available as an accessory.

The standard viewfinder includes a hinged magnifier equipped with an eyepiece for focusing comfort. The magnifier covers the entire ground glass area. The ground glass is a condenser type element with a finely ground base for brighter illumination.

Other features include a film notes device, loops for neckstraps, tripod sockets on both the bottom and side of the camera and an eveready case.

Manufacturer description #2

From the "Equipment information from Exakta" booklet (1954):

We are proud to introduce the eagerly-awaited, new 2 1/4 X 2 1/4-inch (6 X 6-cm) Exakta 66. It is unnecessary to tell Exakta owners what the advantages of such a camera are and how important the new Exakta will be to photographers all over the world. Ihagee has spent many years designing and perfecting this great addition to the single-lens reflex line, and reports from Europe about the camera already have stirred up a bee-hive of interest and enthusiasm. The price is $319.50 with the redesigned 80-mm., f/2.8 Zeiss Jena Tessar lens with built-in preset diaphragm mechanism.

The "66" takes 12 pictures, 2 1/4 X 2 1/4 inches in size, on 120 rollfilm. The shape and design are radically different from the experimental model of this camera, which was available prior to World War II.

The body is now roughly square in shape, measuring 5 1/2 inches high, 4 1/2 inches wide and 4 1/2 inches deep (without lens). All important operating mechanisms are located on the right side.

The two-curtain cloth shutter and two speed setting knobs are similar to those of the 35-mm. Exakta models. The two knobs also are similar to those of the miniature Exakta and provide 29 speed settings ranging from 1/1000 of a second to 12 seconds for instantaneous release. Delayed action exposures can be made up to a speed of 6 seconds.

The new Exakta has an automatic film-transport, shutter-cocking mechanism that operates from the first frame. An ingenious indicator on the camera back indicates that the first frame has been reached. The film-transport mechanism locks until the exposure has been made. Then the film can be advanced only enough to bring the next frame into position. The combination ratchet-type film-transport winder is given a half-turn to advance the film and frame counter and to cock the shutter. Intentional double exposures are possible.

The shutter release is on the right side of the camera on the front of the body next to the lens. It has a safety lock on it.

The interchangeable 80-mm. Tessar, in addition to the preset diaphragm mechanism, has distance scales in both feet and meters. Additional lenses will be available ranging in focal length from 56 to 400 mm. Several wide-angles, f/3.5 Primotars of 85, 165 and 180 mm. and f/5.5 Meyer Tele-Megors of 150, 180, 250 and 400 mm. will be available.

The back of the camera is removable and can be locked with a swinging lever. Interchangeable backs will be available in the future. An indentation in the back affords a fingerhold for grasping and steadying the camera. A folding metal strip below the lens can be used for steadying the camera or balancing it when it is placed on a flat surface.

Built-in flash synchronization is provided by means of a single socket on the left, top side of the camera. The same socket is used for both regular and electronic flash and an adjustable scale permits the time delay to be altered within the 0-20 millisecond range.

The folding viewfinder is removable for interchange with other viewfinders which will be available. The camera will come with the standard viewfinder which can be used at waist level or, if the front window is opened, as an eye-level, sports finder. An eye-level Penta Prism will be available as an accessory.

The standard viewfinder includes a hinged magnifier equipped with an eyepiece for focusing comfort. The magnifier covers the entire ground glass area. The ground glass is a condenser type element with a finely ground base for brighter illumination.

Other features include a film notes device, loops for neckstraps, tripod sockets on both the bottom and side of the camera and an eveready case.

Manufacturer description #3

The Exakta 66 has achieved a high measure of recognition among professional and amateur photographers. This wide acceptance is indicated by the fact that the "66" is in constant use throughout the world on professional, editorial, advertising, fashion, and similar assignments. Be it fashion salons in Paris, bazaars in Bombay, or on New York's Fifth Avenue, you can be sure the "66" is clicking away with consistently brilliant results.

The Exakta 66 is a single-lens reflex camera in which all focusing and viewing take place in the waist-level viewfinder. You see a sparkling, upright and enlarged image on the ground glass. There is no guesswork, no parallax, no complicated procedures. This folding viewfinder is also equipped with a built-in magnifier for critical focusing, or if its front window is opened, can be used as an eye-level, sports finder. The viewfinder assembly is designed to accept a split-image rangefinder; by pressing a button, the unit can be removed for cleaning and inspection.

The "66" is equipped with the famous f/2.8 Carl Zeiss Tessar 80-mm. lens with preset diaphragm mechanism, which focuses from 3 feet to infinity, and stops down to f/22. It incorporates the unique Exakta feature of an extremely wide range of shutter speed settings, from 1/1000 of a second to 12 seconds. The shutter settings are 1/1000, 1/500, 1/250, 1/150, 1/100, 1/50, 1/25, 1/5 and 1/2 of a second and 1, 2, 3, 4, 5, 6, 7, 8, 9, 11 and 12 seconds plus bulb and time. A built-in self-timer is also provided so that the photographer can include himself in the picture. The self-timer works with fast and slow speeds.

Utilizing the popular 120 rollfilm, the "66" takes 12 pictures, 2 1/4 x 2 1/4 inches in size (6 x 6 cm.), in color and black and white. Winding the film automatically cocks the shutter making it possible to take picture after picture with great rapidity. Built into the back of the camera body is a clever indicator that reveals when the first frame is in a picture-taking position. The film transport mechanism locks until the exposure has been made. After the exposure, the film can only be advanced to the next frame. The half turn needed to move the film also cocks the shutter and operates the exposure counter. The shutter release is positioned on the right side of the camera and has a safety lock to prevent unintentional double exposures. However, double exposures can be made when desired.

The "66" has been designed so that lenses can be interchanged in a matter of seconds. A variety of telephoto lenses are available now... more telephoto and wide angle lenses ranging from 56 to 400-mm. will be available. Since you always view through the picture-taking lens, no special viewfinders or attachments are needed with any lens on the "66", be it a telephoto, wide angle, standard or high speed.

Close-up photography with the " 66" is simple. By attaching a bellows extension or a set of extension tubes, you can do wonderful close-up photography. Additional viewfinders are not necessary as the object to be photographed is viewed continuously in the incomparable Exakta viewfinder right up to the moment of exposure.

The Exakta 66 is fully synchronized for regular and electronic flash. A single socket on the left, top side of the camera is used for both types of flash. An adjustable scale permits the time delay to be altered with the 0-20 millisecond range.

The back of the camera is removable and can be locked with a swinging lever. An indentation in the back affords a fingerhold for grasping and steadying the camera.

Compactly designed for easy handling, the "66" is almost square in shape, measuring 5 1/2 inches high, 4 1/2 inches deep and 4 1/2 inches wide (without lens). All important operating mechanisms are located on the right side of the body.

Other features include a film-notes device, loops for neckstraps and tripod sockets on both the bottom and side.

Manufacturer description #4

Photographers prefer the Exakta 66 because of its versatility, large film size, and ability to render perfect results no matter what the assignment. The single lens reflex principle insures complete elimination of parallax at all times, and provides a brilliant ground-glass image. Control over depth-of-field is always in the hands of the photographer who can choose his area of sharp focus by visual observation and with absolute precision. The ground-glass image, large and life-like, eliminates completely squinting and eye-strain, makes picture-taking comfortable and allows the photographer to concentrate on his subject.

The large negative size, 2 1/4 x 2 1/4 inches (6 x 6 cm), provides the advantage of grain-free enlargements up to 16 x 20 inches and beyond. This, combined with a sharp-cutting lens, insures superlative definition which will easily surpass the most critical standards.

Standard lens equipment is the matchless f/2.8 Carl Zeiss Jena Tessar 80-mm lens with pre-set diaphragm, focusing range from 3 feet to infinity, and stops down to f/22. Viewing is through the lens at all times. You see precisely what you get with focusing at maximum aperture, shooting at any pre-determined aperture with a simple twist of the wrist. The built-in magnifier further insures absolute critical focusing. In addition, the snap-up folding viewfinder is combined with an eye-level sportsfinder for complete follow-focus versatility when your subject is in motion.

The "66" offers the unique Exakta range of shutter speeds, including 1/1000, 1/500, 1/250, 1/150, 1/100, 1/50, 1/25, 1/5, and 1/2 second, plus 1, 2, 3, 4, 5, 6, 7, 8, 9, 11 and 12 seconds along with Bulb and Time settings. A self-timer, which operates at both fast and slow speeds, is also built-in.

Popular, 120 rollfilm, available anywhere, is used either color or black-and-white, to provide twelve 2 1/4 inch square pictures. Film wind is linked with shutter cocking, for swift and efficient picture-taking, as well as double exposure prevention, although provision is made for intentional double exposures. In the back of the body you will find a built-in indicator to tell you when the first frame is in taking position. The film transport mechanism locks automatically after winding and until exposure. After exposure, you wind the film to the next frame and feel it come to an automatic stop. A coupling mechanism counts exposures as you transport each frame. The shutter release is conveniently positioned on the right side of the camera body, and features a special safety lock to prevent accidental tripping.

Telephoto lenses all interchangeable in split-seconds with the fool-proof Exakta bayonet mount, are now offered. Focal lengths range from 135mm to 400mm. No extra viewfinders are ever needed, since each lens provides through the lens viewing with all its attendant advantages.

Close-up work with the Exakta "66" is equally simple. Attach the bellows extension to the bayonet mount, or use a set of extension tubes. You'll see the image of the subject right on the ground-glass up until the exact moment of shutter release. As with the lenses, no special viewfinders are necessary. What you see is what you get.

The "66" is fully synchronized for both regular and electronic flash. A single, foolproof outlet at the left, top side of the camera is used for all flash connections. Synchronization delay time is completely adjustable from 0 to a full delay of 20 milliseconds.

Designed to fit into your hand and especially balanced for handling, the Exakta "66" is 5 1/2 inches high, 4 1/2 inches deep and 4 1/2 inches wide (without its lens). All operating mechanisms are conveniently located on the right side of the camera body.

Additional features: a film-notes device, loops for neck-strap and tripod sockets on both bottom and side.

From the editor

The camera was presented by Ihagee East at 1953 Leipzig Autumn Fair and produced for only a few years (most likely 1953-1954).

Subscribe
Notify of
guest

Copy this code

and paste it here *

0 comments
Inline Feedbacks
View all comments

Copyright © 2012-2024 Evgenii Artemov. All rights reserved. Translation and/or reproduction of website materials in any form, including the Internet, is prohibited without the express written permission of the website owner.

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.

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, Leica, Nikon, Pentax, Sony etc.) are always incompatible. In addition to the mechanical and electrical interface variations, the flange focal distance (distance from the mechanical rear end surface of the lens mount to the focal plane) is also different.

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 lens element 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.