Bronica RF645

Medium format MF film rangefinder camera

Specification

Production details:
Announced:September 2000
System: Bronica RF645 (2000)
Format:
Maximum format:Medium format 6x4.5
Film type:120 roll film
220 roll film
Mount and Flange focal distance:Bronica RF645
Shutter:
Type:In-lens leaf shutter
Exposure:
Exposure metering:Through the separate window
Exposure modes:Programmed Auto
Aperture-priority Auto
Manual
Rangefinder and Viewfinder:
Rangefinder:Built-in, combined with viewfinder
Viewfinder:Built-in, combined with rangefinder
Finder magnification:0.6x
Actual rangefinder base:53.5mm
Effective rangefinder base:32.1mm
Bright-line frames:65mm, 135mm
Parallax compensation:Yes
Physical characteristics:
Weight:810g
Dimensions:145.6x107.3x64mm

Manufacturer description #1

TAMRON ANNOUNCES THE NEW BRONICA RF645 6X4.5 FORMAT COUPLED RANGEFINDER CAMERA WITH INTERCHANGEABLE LENSES

September 20, 2000, Photokina, Cologne, Germany-Tamron Co., Ltd. (Kazuyasu Noguchi, President) announces the RF645, a new medium format 6x4.5 coupled rangefinder camera with interchangeable lenses, released under the Bronica brand.

The new products include:

  • BRONICA RF645 Rangefinder Camera
  • ZENZANON 45mm F/4 (with dedicated external viewfinder)
  • ZENZANON 65mm F/4
  • ZENZANON 135mm F/4.5
  • Dedicated Speedlight RF20

Development Background:

From the moment Tamron assumed the initiative for development and sales of Bronica cameras, the company has placed a high priority on pursuit of a new segment for the Bronica camera line. Following extensive market research, this effort has now taken shape in the Bronica RF645: a fully manual coupled rangefinder camera that is highly functional and easy to use, offering rugged durability and superb image quality that makes the most of the 6 x 4.5medium format film size.

In recent years fully automatic cameras have moved to the fore, and those in the medium format category are no exception to this trend. At the same time, manual rangefinder cameras have staged a comeback as a new generation of users begins to explore the potential of this type of camera for creating images with a more personalized touch.

The new Bronica RF645 is a camera that offers accurate, high fidelity image quality. It combines the classic handling of manually operated features with highly sophisticated electronics for an optimum balance of superior image quality, ease of operation and maximum user control.

The Bronica RF645 will be welcomed by advanced amateur photographers seeking to move beyond 35mm to medium format, as well as existing medium format users and working professionals, as the camera responds to a broad range of photographer needs.

  • Employing the 6x4.5 format, the highly accessible standard among medium format cameras, the RF645 was designed for maximum compactness. Consequently, the camera combines the superior quality of the medium format with comfort and ease of handling.
  • Operating dials and switches have been simplified and dedicated according to function, and are designed for maximum visibility and ease of use. The large exposure compensation dial and ISO exposure index dial are positioned on the rear panel for maximum accessibility and swift manual operation.
  • In addition to the painstakingly optimized manual features, a wide variety of high-tech electronic features such as automatic exposure control have also been incorporated to ensure that photographers achieve precisely the results they envision when shooting.
  • To broaden the creative possibilities for users, three high performance interchangeable lenses have been developed for the RF645.
  • Upper casing of the camera chassis is made of magnesium alloy Thixomold, a highly rigid, lightweight material that will protect the delicate internal components of the RF645 for many years.

Main Features:

6x4.5 Coupled Rangefinder Camera

The 6x4.5 format is the most popular for medium format cameras. The Bronica RF645 has realized an easy to operate coupled rangefinder camera by making it as compact as possible.

Maximum Efficiency In Manual Operation

The RF645 was designed to be a practical, easy to use coupled rangefinder camera. Each of the dials and switches has been designed for maximum simplicity and size, to ensure ease of handling and enhanced visibility in a simple, straightforward design.

In particular, the exposure control functions are highly visible and well positioned on the camera back, and can be operated almost entirely by the right thumb. The most frequently used exposure compensation dial was purposely designed without a lock feature with convenience for the professional in mind.

The film advance mechanism is constructed in full manual, allowing full stroke or ratcheted advance. This is made possible by the use of an electronic lens shutter unit. Additionally, the focusing ring is intentionally designed to rotate in the same direction as the rangefinder's horizontal movement for intuitive focusing operation.

Interchangeable Lens Design

The RF645 is the first rangefinder camera in the 6x4.5 format to offer interchangeable lenses.

The three lenses designed for this camera are the wideangle 45mm F/4 (equivalent to 28mm in 35mm format), the standard 65mm F/4 (40mm equivalent), and the telephoto 135mm F/4.5 (80mm equivalent).

Aimed at producing the best possible image quality, our engineers selected the ideal optical composition for each lens. Aberrations are thoroughly corrected, resulting in superb optical performance. The 45mm lens features as standard an Albada type external viewfinder, which renders precise framing over a wide field of view.

High Precision Rangefinder

A top-level dual-image superimposing coupled rangefinder is incorporated, providing the highest level of accuracy and sharp clarity. The viewfinder displays a full view, and utilizes Inverse Galilean type optics for a bright and broad field of view.

The rangefinder is constructed with real image optics fully capable of working efficiently with the 65 mm (40mm equivalent for 35mm) and telephoto 135mm (80mm equivalent). Clear and accurate focusing is made possible with this system. The viewframe used is a bright frame with ambient light. Automatic parallax compensation ensures a viewframe that properly aligns with the image area in accordance with the focusing distance.

Efficient, Comprehensive Data Displays In The Viewfinder

The viewfinder features backlit LCD displays to indicate camera operating status and exposure information. Camera status can be monitored without looking away from the viewfinder. The viewframe switches automatically depending on the angular field of the interchangeable lens, making for optimum framing.

Easy To Use AE/Program AE Systems and Center-Weighted Average Metering

The RF645 employs program AE and center-weighted average metering system for maximum ease of use. Exposure compensation dial and AE lock button are laid out on the camera's rear panel for optimum ease of operation.

  • Aperture-priority AE and Program AE: The two automatic exposure modes include both the conventional aperture-priority mode common to most medium format cameras, as well as program AE. Since capturing fleeting and precious photographic opportunities is the highest priority for photographers, program AE is one more feature that makes the RF645 the ideal choice.
  • Center-weighted, average metering: Center-weighted average metering is considered to be most popular for its simplicity and ease of use, prompting Bronica to select this system for the RF645. The meter is installed on the side of the viewfinder window, using a five-segmented sensor. Differences in light distribution characteristics according to the view angle of each interchangeable lens are compensated for. Whether with wideangle or telephoto, this system measures the light in a well-balanced way.
  • Large Exposure Compensation Dial: The RF645 incorporates a highly visible and easy to operate large sized exposure compensation dial-on the center of the camera's rear panel. This design, taking into account the importance for rangefinder camera users of capitalizing on split-second opportunities, puts quick and appropriate operation first, and by avoiding the dial lock design enables simple operation with the right thumb only. Compensation steps are 1/2 EV, and while in operation the LCD display in the viewfinder displays a "+" or "-" warning symbol.
  • AE Lock: For speedy shooting, functionality of AE lock is critical. The AE lock button features toggle switch operation, and once activated the exposure data will be retained and flashed on the LCD panel display. The photographer can then take as many shots at this setting as desired, without fear of the AE lock setting being released unexpectedly. (AE lock settings will be cleared only after five minutes without use or if the main switch is turned off.)

Fully Electronically Controlled Lens Shutter Unit

The shutter utilizes a fully electronic control system for the aperture control and shutter charge operations. An actuator incorporated in the unit commands this newly developed shutter.

The interface between the lens and camera mount section is performed by an electronic connection, ensuring fully electronic control of the exposure systems between lens and camera. This makes incorporation of the program AE possible, which was difficult with conventional lens shutter unit systems. Unlike traditional lens shutter units, there is no mechanical spring tension involved, resulting in a quieter, more stable shutter action.

Auto Charging System:

A More Practical Shutter Release The RF645 features an automatic shutter cocking system that charges the shutter automatically immediately after shutter release. This shutter unit conducts shutter charging independently from film advance operation, and the system is sequenced so that charging takes place as soon as the shutter completes a open/close cycle. Through use of this system, a comfortable shutter action can be enjoyed similar to automatic film winding cameras, while meeting with the manual film advance mechanism both in full stroke and rocketed operation.

Top Speed of 1/750th Second

Through employment of a fully electronic lens shutter with its stable, regulated shutter speed, our design engineers have succeeded in achieving a maximum shutter speed of 1/750th of a second (only in Program AE with an aperture setting of F/22.).

Newly Developed Light Shielding Curtain To Prevent Accidental Film Exposure

In order to prevent exposure of the film when changing lenses, a light shielding curtain is activated when removing and replacing lenses. This newly developed structure facilitates swift interchange of lenses.

A Solid, Appealing Metal Casing and Magnesium Alloy Top Cover

The RF645 employs a large proportion of metal components in the body construction to ensure solid structural strength as well as quality feel and handling characteristics. The front plate which serves as the main body frame and interchangeable lens mount is die cast, the bottom plate is of brass and the top cover which houses the rangefinder is of hard, lightweight magnesium alloy. The leading edge magnesium Thixomolding* injection method is employed to give the casing the hardness of metal and a complex shape required for this innovative design: one that cannot be attained through conventional press stamping.

*Unlike conventional high temperature, high pressure die casting, magnesium Thixomolding is achieved by injecting near-solid magnesium alloy chips into metal molds, much like the plastic injection molding process. This method prevents temperature warping and requires little finishing work, thus making it ideal for line production. Since the injection mold is used, this method also allows for great freedom of shape in product design.

Manufacturer description #2

Camera Type: Coupled-meter rangefinder, lens shutter 6 X 4.5 format camera

Picture Format: 41.5 mm X 56 mm

Film: 16 frames on 120 type film, 32 frames on 220 type film

Shutter: Bronica No. 00 type electronically controlled lens shutter in each lens, shutter speeds: B, 1 to 1/500 sec. (on manual without intermediate speeds), 8 to 1/500 sec. (on aperture-priority AE mode, 1/12-stop increment control), 8 to 1/750 sec. (on programmed AE mode, 1/12-stop increment control). Electronically timed self timer with 10 sec. delay time

Advance: By rapid winding lever placed on top of camera with either 186 deg. single stroke or ratcheted strokes, with 12 deg. standby angle

Rangefinder: Dual-image superimposing real image optical system, with 53.5 mm base line (effective base line: 33 mm)

Viewfinder: Inverse Galilean optical system with coupled rangefinder bright frames automatically switched between 65 mm and 135 mm lens and automatically corrects parallax, finder magnification 0.6X, viewing field 81% at 3 m

In-Finder Display: Shutter speeds, lens aperture, correct exposures, flash ready, exposure compensation warning, AE L warning, multiple exposure (ME) warning

Exposure Metering: Center-weighted area-comparative metering system, metering range EV 3 to EV 18 (65 mm f/4, ISO 100), film speed range: ISO 25 to 1600, exposure compensation range: +2 to -2 EV (1/2-stop increment)

Exposure Control Modes: Manual, Aperture-priority AE and Programmed AE modes

Battery: 2 cells of CR2, 3V Lithium type battery

***

The RF645 features a high accuracy, easy to view dual image superimposing rangefinder. The rangefinder employs a superb quality real image optical system using mechanical and optical components of the highest precision design and manufacture. Focusing is clear and precise. The readily visible bright frame technology utilizes automatic parallax compensation that adjusts the frame to the point of focus for optimum framing.

In addition to Aperture-priority AE and full manual mode, the on-board metering system provides Program AE mode that makes it possible to capture those once in a lifetime images. All of the camera controls are available at your fingertips creating the perfect balance between automatic and manual control.

The entire system is engineered with key devices such as a newly developed super silent electronic lens shutter and an automatic light shielding curtain, which is activated whenever a lens is removed from the camera.

The shutter unit operations including shutter blade action, diaphragm movement and shutter recharge are all electronically controlled by an actuator inside the unit. This represents Bronica's first fully electronic shutter system.

A major difficulty increating an interchangeable lens with built-in shutter is that the camera body construction must prevent the film from being exposed when switching lenses. The lens removal and attachment mechanism activates a light shielding curtain to automatically cover the fil m surface.

It's no secret that a simple design is often the most effective. Combining rugged construction with intuitive control placement creates an instant bond between the RF645 and you.

At Bronica, we have never considered the camera to be a mere tool of the trade for photographers. True professionals form a special bond with their cameras, a kind of partnership, working together to capture precious scenes that may never come again. The feel, the handling, the action: all these combine to make the camera much more than just a meansof shooting photographs.

When we set out to design the RF645, our goal was to create a camera that photographers would love to handle, that would lead them into new creative territory. We aimed to design a new kind of rangefinder camera. In the RF645, we think we have succeeded.

Serious about combining structural strength with superior design and handling, we turned to advanced metal alloys for much of the body casing. The main body and front facing are die cast, the bottom plate is of brass, and the upper housing enclosing the viewfinder and integrated rangefinder mechanism is made of magnesium alloy.

Manufacturer description #3

BRONICA MEDIUM FORMAT BUSINESS TERMINATED

Rapid Shift to Digital SLRs by Bronica’s Core Customer Base Prompts Move to Terminate Bronica Medium Format Business

October 14, 2005, Commack, New York — Tamron USA, Inc. announced today that it has discontinued the production of the Bronica RF645 6x4.5 range finder camera model along with its relevant interchangeable lenses and accessories. The discontinuation of this last Bronica model marks the termination of the Bronica brand business. Bronica withdraws from the medium format camera business after 47 years since its first model, the Zenza Bronica D, was introduced in 1959.

Due to the drastic worldwide shift to digital over the past few years, medium format business has suffered, particularly in the portrait and wedding photography segment, the core customer base for Bronica cameras. “I believe we all understand the issues at hand when it comes to the business of medium format,” stated Kenji Nakagawa, Sales Manager of Tamron headquarters’ Overseas Sales & Marketing Department in Japan. “We have been struggling to find the best possible solution for the medium format camera business under the Bronica brand, but after careful study and the comprehensive consideration of the market situation, we have concluded that there is no other choice but to end this business.”

Bronica sales have drastically dropped as age of digital photography rapidly eclipses the film era. The quick adoption and shift to digital technology by the core Bronica customer, professional portrait and wedding photographers, accelerated the decline in Bronica business faster than other brands of medium format equipment. “For many years, Bronica cameras have been the workhorses used to photograph hundreds of thousands, perhaps millions, of weddings around the world,” stated Stacie Errera, Chief Marketing Officer for Tamron USA, Inc. “However, for these photographers, who collectively made up a huge percentage of our installed customer base, digital SLRs produce satisfactory image results, higher creativity options and increased profits (after the initial issues of workflow and printing were worked out by most), which made the switch to digital almost unanimous among this group of professional photographers.”

Tamron USA, Inc. is fully prepared to carry on servicing Bronica equipment for seven years from the official date of discontinuation of each model. “While I understand the market situation and the need to discontinue the Bronica line, I must admit that I was a little disappointed,” stated Pat Simonetti, Technical & Customer Service Manager of Tamron USA, Inc. “We are well prepared to continue servicing our users and thank them all for their support over the years.”

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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, Nikon, Pentax, Sony etc.) are always incompatible. In addition to the mechanical and electrical interface variations, the flange focal distance can also be different.

The flange focal distance (FFD) is the distance from the mechanical rear end surface of the lens mount to the focal plane.

Lens construction

Lens construction – a specific arrangement of elements and groups that make up the optical design, including type and size of elements, type of used materials etc.

Element - an individual piece of glass which makes up one component of a photographic lens. Photographic lenses are nearly always built up of multiple such elements.

Group – a cemented together pieces of glass which form a single unit or an individual piece of glass. The advantage is that there is no glass-air surfaces between cemented together pieces of glass, which reduces reflections.

Focal length

The focal length is the factor that determines the size of the image reproduced on the focal plane, picture angle which covers the area of the subject to be photographed, depth of field, etc.

Speed

The largest opening or stop at which a lens can be used is referred to as the speed of the lens. The larger the maximum aperture is, the faster the lens is considered to be. Lenses that offer a large maximum aperture are commonly referred to as fast lenses, and lenses with smaller maximum aperture are regarded as slow.

In low-light situations, having a wider maximum aperture means that you can shoot at a faster shutter speed or work at a lower ISO, or both.

Closest focusing distance

The minimum distance from the focal plane (film or sensor) to the subject where the lens is still able to focus.

Closest working distance

The distance from the front edge of the lens to the subject at the maximum magnification.

Magnification ratio

Determines how large the subject will appear in the final image. Magnification is expressed as a ratio. For example, a magnification ratio of 1:1 means that the image of the subject formed on the film or sensor will be the same size as the subject in real life. For this reason, a 1:1 ratio is often called "life-size".

Manual focus override in autofocus mode

Allows to perform final focusing manually after the camera has locked the focus automatically. Note that you don't have to switch camera and/or lens to manual focus mode.

Manual focus override in autofocus mode

Allows to perform final focusing manually after the camera has locked the focus automatically. Note that you don't have to switch camera and/or lens to manual focus mode.

Electronic manual focus override is performed in the following way: half-press the shutter button, wait until the camera has finished the autofocusing and then focus manually without releasing the shutter button using the focusing ring.

Manual diaphragm

The diaphragm must be stopped down manually by rotating the detent aperture ring.

Preset diaphragm

The lens has two rings, one is for pre-setting, while the other is for normal diaphragm adjustment. The first ring must be set at the desired aperture, the second ring then should be fully opened for focusing, and turned back for stop down to the pre-set value.

Semi-automatic diaphragm

The lens features spring mechanism in the diaphragm, triggered by the shutter release, which stops down the diaphragm to the pre-set value. The spring needs to be reset manually after each exposure to re-open diaphragm to its maximum value.

Automatic diaphragm

The camera automatically closes the diaphragm down during the shutter operation. On completion of the exposure, the diaphragm re-opens to its maximum value.

Fixed diaphragm

The aperture setting is fixed at F/ on this lens, and cannot be adjusted.

Number of blades

As a general rule, the more blades that are used to create the aperture opening in the lens, the rounder the out-of-focus highlights will be.

Some lenses are designed with curved diaphragm blades, so the roundness of the aperture comes not from the number of blades, but from their shape. However, the fewer blades the diaphragm has, the more difficult it is to form a circle, regardless of rounded edges.

At maximum aperture, the opening will be circular regardless of the number of blades.

Weight

Excluding case or pouch, caps and other detachable accessories (lens hood, close-up adapter, tripod adapter etc.).

Maximum diameter x Length

Excluding case or pouch, caps and other detachable accessories (lens hood, close-up adapter, tripod adapter etc.).

For lenses with collapsible design, the length is indicated for the working (retracted) state.

Weather sealing

A rubber material which is inserted in between each externally exposed part (manual focus and zoom rings, buttons, switch panels etc.) to ensure it is properly sealed against dust and moisture.

Lenses that accept front mounted filters typically do not have gaskets behind the filter mount. It is recommended to use a filter for complete weather resistance when desired.

Fluorine coating

Helps keep lenses clean by reducing the possibility of dust and dirt adhering to the lens and by facilitating cleaning should the need arise. Applied to the outer surface of the front and/or rear lens elements over multi-coatings.

Filters

Lens filters are accessories that can protect lenses from dirt and damage, enhance colors, minimize glare and reflections, and add creative effects to images.

Lens hood

A lens hood or lens shade is a device used on the end of a lens to block the sun or other light source in order to prevent glare and lens flare. Flare occurs when stray light strikes the front element of a lens and then bounces around within the lens. This stray light often comes from very bright light sources, such as the sun, bright studio lights, or a bright white background.

The geometry of the lens hood can vary from a plain cylindrical or conical section to a more complex shape, sometimes called a petal, tulip, or flower hood. This allows the lens hood to block stray light with the higher portions of the lens hood, while allowing more light into the corners of the image through the lowered portions of the hood.

Lens hoods are more prominent in long focus lenses because they have a smaller viewing angle than that of wide-angle lenses. For wide angle lenses, the length of the hood cannot be as long as those for telephoto lenses, as a longer hood would enter the wider field of view of the lens.

Lens hoods are often designed to fit onto the matching lens facing either forward, for normal use, or backwards, so that the hood may be stored with the lens without occupying much additional space. In addition, lens hoods can offer some degree of physical protection for the lens due to the hood extending farther than the lens itself.

Teleconverters

Teleconverters increase the effective focal length of lenses. They also usually maintain the closest focusing distance of lenses, thus increasing the magnification significantly. A lens combined with a teleconverter is normally smaller, lighter and cheaper than a "direct" telephoto lens of the same focal length and speed.

Teleconverters are a convenient way of enhancing telephoto capability, but it comes at a cost − reduced maximum aperture. Also, since teleconverters magnify every detail in the image, they logically also magnify residual aberrations of the lens.

Lens caps

Scratched lens surfaces can spoil the definition and contrast of even the finest lenses. Lens covers are the best and most inexpensive protection available against dust, moisture and abrasion. Safeguard lens elements - both front and rear - whenever the lens is not in use.