Mamiya 645 PRO

Medium format MF film SLR camera


Production details
System: Mamiya M645 (1975)
Imaging plane
Maximum format:Medium format 6x4.5
Mount and Flange focal distance:Mamiya M645 [63mm]
Imaging plane:56 × 41.5mm film
Model:Electronically controlled
Speeds:4 - 1/1000 + B
Exposure metering:None
Exposure modes:Manual
Physical characteristics

Manufacturer description

Mamiya pioneered the 6x4.5 film format and introduced the world’s first 645 SLR in 1975. The 645 PRO is the latest masterpiece in this series and incorporates all the latest mechanical, electronic and optical advances. Its external appearance, too, has been modernized and its ergonomic design further enhanced.

The 645 PRO has a built-in self-timer (delayed shutter release) which will also facilitate time exposures. Attaching special leaf shutter lenses will automatically set the focal plane shutter to 1/8 sec. Heavy duty gears connect to the improved Power Drive Grip WG401. This grip also automatically cocks the leaf shutter lenses and permits remote control.

The AE Prism Finder FE401, specially created for this camera, automates exposure and shows LED safety signals. 35mm film holders now come with panoramic adapters. A super fast 300mm f/2.8 APO lens was also designed for this camera.

Special features of the Mamiya 645 PRO:

1. 3 x More Negative Area Than the 35mm Format Plus Superior Image Quality From Mamiya World-Class Lenses

The 6x4.5cm format offers approx. 3 times more image area than the 35mm (24x36mm) format, Man’s vision is horizontal and rectangular.

Film Holders are rectangular and so are most pictures in them. The 6x4.5 format is also large enough to be viewed without a magnifier and its aspect ratio (horizontal / vertical) is ideal, requiring minimum cropping. Mamiya’s high performance medium format lenses assure sharpness and beautiful color fidelity.

2. Sturdy, Versatile, Safe and Highly Reliable Body - Tailored to Satisfy Pro Needs

Introduced in 1975 to not only provide an alternative to the 35mm format, but to afford the user with advanced versatility given its much larger format, the Mamiya 645 Series is constantly being upgraded. Elements such as speed and handling plus a host of other special features have been enhanced to satisfy the needs of most demanding professionals.

Two new convenient safety features have been added to the 645 PRO in the form of state-of-the-art optoelectronics which immediately identifies problems with the shutter (i.e. when it will not release) when the AE Prism Finder FE401 is used. Whether these malfunctions develop from failure to draw out the Dark Slide, or if there are problems in film take-up, the LED will indicate the source of the trouble. With these new advancements, Mamiya believes the most demanding pro will be more than satisfied with the new edition 645.

3. Enhanced Interchangeable Roll Film Holder System - Enables Polaroid and Even 35mm Panoramic Photography

The 645 PRO features an interchangeable film holder system capable of using a far wider range of roll film holders than before. Depending on the application, the system can be quickly attached to or detached from the camera, ensuring the ability to catch even fast changing scenes. It also features fail-safe devices including, for example, one that warns when you have failed to take out the dark slide when the AE Prism Finder FE401 is being used.

4. Interchangeable Viewfinders

1. AE Prism Finder FE401

The AE (automatic exposure) Prism Finder FE401 features three modes of TTL metering, including automatic switching from center-weighted averaging to spot metering. It also has a +/-3EV exposure compensation adjustment.

2. Prism Finder PF401

The Prism Finder PF401 is without metering electronics and designed for manual photography mode. Both Prism Finders show an unreversed, upright image and are ideal for eyelevel photography.

3. Waist Level Finder N

The Waist level Finder N is desirable for low angle photography and particularly for horizontal composition. A self erecting hood with built-in magnifier shields groundglass from all ambient light. A built-in sportsfinder permits eyelevel viewing and is ideal for action photography.

5. Bright, Dynamic Images Visible on the Focusing Screen

5 Selectable Types Available

The 645 PRO can reproduce bright, dynamic and sharp images on the focusing screen, enabling optimum composition to be obtained according to the photographic purpose. In addition, the 645 PRO greatly enhances focusing.

5 types of focusing screens are available to facilitate photographing a wide variety of subjects.

6. A Comprehensive Series of Interchangeable Lenses - Sharp Images and Outstanding Color Balance

There are an amazing variety of interchangeable lenses in the PRO 6 x 4.5 format series. Mamiya has concentrated an all-out effort on the systematic production of lenses in an effort to satisfy a multitude of needs. All lenses are multi-coated to eliminate flare and ghosting even under the most adverse light conditions. While the series now also features three leaf shutter lenses, all lenses exhibit the utmost in color balance, high resolution and crystal clear definition. A feature lens is the new 300mm f/2.8 APO lens which eliminates chromatic aberration and produces photos with the sharpest definition. Given the wide variety of lenses in the 645 PRO Series, they greatly expand the world of images that are possible.

7. Auto winding with the Power Drive Grip WG401

This Power Drive Grip WG401 has been specially designed for heavy duty, motorized operation with the 645 PRO. It also permits automatic shutter cocking of the leaf shutter lenses and can be remote controlled. Another feature, not available previously is the following:

When attaching a partially exposed film holder (in which the film has not been advanced to a new frame), to the 645 PRO equipped with the Power Drive Grip WG401, a built-in camera mechanism will automatically advance the film to the next frame, when the shutter release is activated, either on the camera body or on the Power Drive Grip WG401.

8. New Automatic Leaf Shutter Lenses for added versatility

55mm (Wide Angle), 80mm (Standard), 150mm (Telephoto) lenses

These lenses are all in Seiko #0 shutter, offer the advantages of syncroflash photography at all shutter speeds 1/ 30, 1/60, 1/125, 1/250 and 1/500sec. The optional Power Drive Grip WG401 will automatically cock the shutters as it transports the film and moves the mirror.

The camera’s focal plane shutter must be set at 1/8 sec. for leaf shutter mode operation. The leaf shutter lenses can do it automatically.

9. A Broad Accessory System For Specialized Applications

A useful accessory system to serve the specialized needs of the photographer. It includes Auto Bellows and Auto Extension Rings for close-up and copying work; Infrared Remote Control for studio and nature photography; External Battery Case for operating in cold surroundings; Camera Grips for convenient holding and more.

10. Other Features

Mirror Lock-up

After focusing, the Mirror can be locked up before making an exposure. This is convenient when the camera is used at slow shutter speeds and is mounted on a tripod for telephotography, copy work, etc., since even a very small amount of vibrations should be eliminated.


Self-timer for delayed shutter release. When activated it will light a red pilot lamp in the front of the camera for eight seconds and will blink for two seconds before triggering the shutter.

Time Exposure

Time exposures are made by utilizing the Self-timer and the “B” shutter setting. A new power saving circuit design switches the battery off and extends is life.


CAMERA TYPE: 6 x 4.5cm electronic focal-plane shutter SLR.


FILM TYPE: 120 roll film (15 exposures). 220 roll film (30 exposures). Polaroid Pack film (Polaroid 100, 600 series). 135 roll film in film cartridge

FILM LOADING: Daylight loading-interchangeable film holders with film speed dial available.

LENS MOUNT: M645 bayonet mount.

SHUTTER: Moving coil, electronic controlled focal-plane shutter.

SHUTTER SPEED: (Manual) 4 sec. - 1/1000 sec., B (T). (Auto) 8 sec. - 1/1,000 sec. (when the AE Prism Finder FE401 is used)

SHUTTER RELEASE: Electromagnetic release. Selectable release lock or self-timer mode.

MIRROR: Instant return, front coated mirror, with mirror lock-up capability.

VIEWFINDER: Interchangeable (Waist Level Finder N, Prism Finder FP401 and AE Prism Finder FE401) (Viewfinders for the M645 Super can be used).

FOCUSING SCREEN: Standard: Rangefinder Spot/Microprism with Fresnel lens, accessory screens available (Same as the M645 Super).


FILM TRANSPORT: Single turn winding by Film Advance Crank AC401. Variable crank start position (6 positions). Interchangeable (Power Drive Grip WG401 and Power Drive Grip N).

EXPOSURE COUNTER: Progressive type, automatic reset. The counter for 120 and 220 film will be automatic.

MULTIPLE EXPOSURE: Activated by the Multiple Exposure Lever.

DEPTH-OF-FIELD: Depth-of-field Scale provided on lens.

SELF-TIMER: Electronic LED display Lights for 8 seconds, flashes for 2 seconds, before shutter release. Has manual override.

AUXILIARY SHUTTER RELEASE SOCKET: Accepts Remote Control and Electronic Cable Releases.

BATTERY CHECK: The-Battery Check Button, indicates residual battery capacity in 3 stages.

TIME EXPOSURE: Time (T) photography can be taken.

SYNCHRONIZATION: X terminal plus hot shoe, Flash synchronization at 1/60 sec. or slower speeds

BACK COVER: Dark Slide Storage, Memo Clip.

POWER SUPPLY: 6V battery x 1 (4SR44 silver-oxide battery, 4LR44 alkaline-manganese battery or 2CR1/3 lithium battery).

OTHERS: With neck strap.

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Copyright © 2012-2023 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.

35mm full frame

43.27 24 36
  • Dimensions: 36 × 24mm
  • Aspect ratio: 3:2
  • Diagonal: 43.27mm
  • Area: 864mm2

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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. 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.