Mamiya 645AF

Medium format AF film SLR camera

Mamiya 645AF


Production details:
Announced:March 1999
System: Mamiya M645 (1975)
Maximum format:Medium format 6x4.5
Film type:120 roll film
220 roll film
Mount and Flange focal distance:Mamiya M645 [63mm]
Model:Electronically controlled
Speeds:30 - 1/4000 + B, T
Exposure metering:Through-the-lens (TTL), open-aperture
Exposure modes:Programmed Auto
Aperture-priority Auto
Shutter-priority Auto
Physical characteristics:

Manufacturer description #1

ELMSFORD, NY; March 1, 1999: Mamiya America Corporation proudly announces the introduction of the Mamiya 645 AF (Autofocus) System. Mamiya pioneered the 645 SLR system over 25 years ago and continues their long tradition of expertise and excellence with the newest autofocus addition to the system. The MAMIYA 645 AF offers a bevy of new features combined with world-class Mamiya performance. The MAMIYA 645 AF is the realization of years of careful research and development by Mamiya to make operation swift and decisive to meet the demands of professionals around the globe.

The MAMIYA 645 AF utilizes a TTL (through-the-lens), phase-difference-detection type auto-focus system. An automatic infrared sub-beam enables the user to focus easily even on subjects of low contrast or low illumination. Single AF (focus priority) or Continuous AF (release priority) can be selected with the AF mode dial.

Equipped with a metal focal plane shutter of max 1/4000 sec., the MAMIYA 645 AF encourages all kinds of photographic uses, from portraiture with wide-angle lenses to high speed shooting to capture fast action with telephoto lenses. Combine the electronically controlled shutter speeds with 1/2 stop adjustment with autofocus and capturing decisive moments with precision is even easier than ever possible in medium format.

The vertically-running, metal focal plane shutter has a high flash sync speed of 1/125 sec, useful for mixing flash and ambient light in daylight situations.

Dial-type exposure mode settings enables the user to confirm the active mode at a glance. Shutter speed and aperture values can be set in 1/2 steps using the two electronic dials. In AE mode, the shutter speeds and aperture values are controlled automatically in 1/8 stop increments.

The MAMIYA 645 AF Incorporates an intelligently designed interactive control system between the internal controls in the body, new AF interchangeable lenses and the motorized interchangeable film magazines. This interactive system makes it possible to control each component most precisely without fail and to support further system development in an eminent electronic imaging era. Exposure modes on the MAMIYA 645 AF can be set to Aperture priority, Shutter priority and full Program AE. A metered manual mode is also available for complete user control. The program AE can satisfy every kind of shooting idea with its ± 1.5 step shifting function to both high and low speed sides.

The MAMIYA 645 AF has three metering modes: Center-weighted average, Spot, and Auto A-S (Variable ratio). The new auto-bracketing function exposes three frames consecutively and can be selected in 1/3, 2/3 or 1 stop increments, making difficult shooting situations even easier. Separate exposure compensation controls allow adjustment of ±3 EV in 1/3 stop increments. Making the best use of Mamiya’s world-class techniques of lens design and state-of-the-art optical glass, the line of 7 new autofocus AF lenses and 22 manual focus interchangeable lenses for Mamiya 645 AF can fully satisfy tough requirements of professional photographers. Mamiya uses Ultra Low Dispersion (ULD) glass to correct Iateral chromatic aberration so that the professional can expect high contrast and resolution from minimum to maximum aperture with Mamiya’s world-class wide angle lenses. Additionally, the floating element mechanism enables the user to utilize the entire range of the lens from close-up to infinity while minimizing field-curvature, common in wide angle lenses. High contrast and clear image reproduction is Mamiya’s elimination of as much ghost and flare spot as possible with telephoto lenses through computer-aided design and choice of superior glass elements.

Paying close attention to environmental protection and effective use of natural resources, Mamiya uses eco-glass, which contains no lead or arsenic, maintaining their company policy to be “Earth-friendly, Nature-friendly”.

The MAMIYA 645 AF utilizes the newly designed Mamiya 645 AF mount, which accepts the 22 current world-class M645 series lenses. In consideration of the loyal users of the Mamiya 645 system for the last 25 years, all manual focus lenses are compatible with the new MAMIYA 645 AF. The non-AF lenses now have focus confirmation capability and stopped-down AE metering, taking on new life in the 645 AF system.

Mamiya’s tradition of serving the professionals interest with interchangeable film magazines is continued with the new MAMIYA 645 AF. Both 120 and 220 roll film can be loaded in the magazines, which are driven by the built-in power winder in the MAMIYA 645 AF BODY. By rotating the pressure plate, the switch between film 120 and 220 is made simply and swiftly. A Polaroid film holder magazine is also available for on-the-spot proofing and light level evaluation. The interchangeable film magazine system also enables MAMIYA 645 AF owners to “go digital” with a number of compatible digital backs.

The 645 AF is equipped with the TTL direct flash control system to support Metz's SCA3000 module system. One can tackle a wider variety of situations using the automatic TTL flash exposure, including daylight synchronization and macro photography. Exposure data can be imprinted outside the image area. The feature is user-selectable, and the information one can have recorded on each exposure include Exposure Mode, Aperture, Shutter Speed, Exposure Compensation, Metering Mode and ID Number. In DATA mode the exposure number is recorded on the film. In the DAY mode, the Year/Month/Date/Time and ID number are imprinted on the film.

The three-digit ID number is indicated as sequential numeric data (001-999). Most important, the data is in the camera body’s memory, making it possible to continue the exposure number sequence without a break even when the film magazines are changed (Data increment method). This is indispensable to the professional who needs to catalogue a large shoot in a worry-free manner.

The exterior LCD display, and larger letters on the display of the body, clearly describe present shooting conditions/settings. The LCD display is back-lit for dark situations, and this function can be can be switched off when not desired. The date on the LCD of the interchangeable film magazine is linked with that of the camera body.

The MAMIYA 645 AF is the first medium format camera to use a magnesium alloy in the production of the top cover. The result is a solid, more rugged exterior which feels good to the touch.

The MAMIYA 645 AF will be available in the October 25, 1999.

Manufacturer description #2

Mamiya pioneered the 645 SLR system camera three decades ago and the Mamiya 645 AF, with its TTL auto-focus, auto-exposure, auto-flash and auto-film winding features, is the latest Mamiya master piece and reflects its long tradition of medium format camera expertise.

Combining 35mm handling ease and speed with the advantages of an almost 3x larger image size, it is a full-featured camera, utilizing many digital controls, LCD displays and is ready for the age of digital photography.

Its high-tech focal plane shutter with speeds to 1/4000 sec. permits sync flash up to 1/125 sec. and has an exclusive "Safety Retraction" feature, which protects it against accidental damage.

The AE Prism Finder with its many features, protected by a sturdy magnesium housing, and also the Power Drive Grip, are now integral components of the diecast aluminum camera body, designed for heavy professional use.


CAMERA TYPE: 6x4.5cm format, electronically controlled focal-plane shutter, TTL multiple mode AE, AF single lens reflex


FILM TYPE: 120 roll film (16 exposures); 220 roll film (32 exposures); Polaroid Land Pack Film (requires special HP402 magazine)

LENS MOUNT: Mamiya 645 AF Mount, compatible with M645 Mount (manual focus confirmation, focus aid, stopped-down exposure metering)

VIEWFINDER: Fixed prism viewfinder magnification x0.71; built-in diopter adjustment (-2.5 to +0.5, separate diopter correction lenses provide adjustment ranges of -5 to -2 diopter and 0 to +3 diopter); built-in eye-piece shutter

FOCUSING SCREEN: Interchangeable between Matte (standard) and Checker and Microprism Type C for Non-AF M645 lenses.

FIELD OF VIEW: 94%* of actual image

VIEWFINDER INFORMATION: Focus mark, out-of-focus direction mark, aperture value, shutter speed, metering mode (A, S, A/S), exposure compensation value (difference between set value and actual value) and flash ready / OK lamp with TTL Metz connection.

AF SUB-BEAM: activates automatically under low light, low contrast. Range: 9m, Automatic switching to flash unit's built-in sub-beam when Metz flash unit is attached.

AF LOCK: Half-press on shutter release in S Mode

EXPOSURE CONTROL MODES: Aperture-priority AE, shutter-priority AE, programmed AE (PH, PL setting possible)

METERING METHOD: Center-weighted average (AV), spot (S) and variable ratio (1.5-step A-S auto change by program shift setting), manual

SETTING STEPS: Shutter speed and aperture both can be set in half-stop increments; electronic dial lock

LIGHT METERING: TTL metering; center-weighted average (AV), spot (SP), and auto A-S variable ratio

METERING RANGE: EV 2 to EV 19 (with IS0 100 film, f/2.8 lens)


FILM SPEED: ISO 25 to 6400

AE LOCK: With AEL button; released by pressing twice or shutter operation; light metering value differentiation in viewfinder exposure compensation display when ELS button is held down; ±6EV (1/3 step)

SHUTTER: Electronically controlled vertical metal focal-plane shutter. (vertical travel)

SHUTTER SPEED: AE 30 to 1/4000 sec. (1/8 step), manual 30 to 1/4000 sec. (1/2 step), X, B (Bulb, electronically controlled), T (time, mechanically controlled), emergency shutter curtain open mechanism (open when magazine is removed, automatically closed when magazine is attached)

AUTO-BRACKETING: Enabled with Mode button, 1/3, 1/2, 2/3, 1-step units

FLASH SYNCHRONIZATION: 1/125 sec., automatically sets to 1/125 at faster speeds, synchronized to displayed speed at slower speeds (when Metz flash unit is used)

FLASH CONTROL: TTL direct metering, supports Metz SCA3000 system (SCA3951 Adapter)

FILM TRANSPORT: Automatic via built-in motor, single or continuous exposures

FILM LOADING: Automatic advance to first frame when shutter release button is pressed once (Easy Loading)

MULTIPLE EXPOSURE: Enabled with Mode button (1 to 5 exposures); can be cancelled

MAIN LCD PANEL: On camera body; shows aperture value, shutter speed value, self-timer, BL (Backlight), battery check, multiple exposure, programmed AE or programmed AE shift value, data imprinting Interchangeable Film Magazine: ISO speed, type of film (120/220), exposure number

DATA IMPRINTING: 7 segment dot matrix; DATA mode: exposure mode, aperture value, shutter speed value, exposure compensation, metering mode, ID number; DAY mode; year, month, date, time, ID number Switchable between enabled and disabled

SYNC TERMINAL: X contact (sync speed 1/125 sec.)

CABLE RELEASE SOCKET: On shutter button

REMOTE-CONTROL TERMINAL: On side of body; electromagnetic cable release

SELF-TIMER: 3 to 60 sec. (standard: 10 sec., can be set in 1 sec. steps between 3 and 10 sec., and in 10 sec. steps between 10 and 60 sec.)


TRIPOD SOCKET: U 1/4 inch and U 3/8 included

POWER REQUIREMENTS: 6 AA-size batteries (alkaline-magnesium, lithium)

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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 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 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 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.


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 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 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.


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.


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.


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.


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 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),


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


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.


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.


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.


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 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.