Contax RTS II Quartz

35mm MF film SLR camera



Production details:
System: Contax/Yashica (1975)
Maximum format:35mm full frame
Film type:135 cartridge-loaded film
Mount and Flange focal distance:Contax/Yashica [45.5mm]
Model:Electronically controlled
Speeds:16 - 1/2000 + B
Exposure metering:Through-the-lens (TTL), open-aperture
Exposure modes:Aperture-priority Auto
Physical characteristics:

Manufacturer description #1

Type: 35 mm single-lens reflex featuring electronically controlled AUTO/manual exposure, focal plane shutter.

Image size: 24 x 36 mm.

Lens mount: Contax/Yashica mount.

Standard lenses: Carl Zeiss Planar T* 50 mm f/1.4, Carl Zeiss Planar T* 50 mm f/1.7

Shutter: Quartz-timed, electronically operated horizontal-travel titanium focal-plane shutter.

Shutter Speed: AUTO mode.... 1/2000 to 16 sec. Manual mode.... 16 settings of X (1/60 sec.), 1/2000 to 4 sec., and "B"; and when out of battery, mechanical shutter with settings of 1/50 sec. and "B"

Synch Terminals: X Contact (synch speed 1/60 sec.), direct X contact, and synch terminal.

Self-Timer: Quartz-timed electronic self-timer with 10 sec. delay. LED flashes during operation, accelerating 2 sec. before shutter release. Can be cancelled during countdown.

Shutter Release: Real Time Electromagnetic Release System; auxiliary remote release via "Release Socket".

Exposure Modes: Aperture priority automatic exposure; and manual exposure

Exposure Control: Through-the-lens (TTL) center-weighted metering at full aperture using SPD (Silicon Photo Diode) cell. EV range from EV -1 (f/1.4 at 4 sec.) to 19 (f/16 at 1/2000 sec.) at ASA 100 with f/1.4 lens. ASA range from 12 to 3200.

Auto Flash Control: Direct TTL metering automatically coupling with Contax TLA Auto Flash system via an SPD sensor. Synch speed: Shutter speed automatically set to 1/60 sec. upon completion of recycling.

Exposure Check Button: Pressing button activates LED display for 16 sec.

Exposure Compensation: +2 EV ~ -2 EV via exposure compensation dial (click stops at every 1/2 EV; can be set for in-between-click stops).

AE Lock: Lever type (locks in exposure value metered at image plane)

Viewfinder: Eye-level pentaprism type • Field shows 97% of picture area; Magnification ratio 0.87X (50 mm standard lens) • Viewfinder eyepiece-blind: lever operated

Focusing Screens: Microprism focusing screen comes as standard equipment. Seven other interchangeable type screens are available

Viewfinder Display: Aperture display, exposure compensation display (LED digital display - red), shutter display; over- or under-exposure display (alphanumerical LED array - red), TLA flash unit flash ready/after flash signal mark (LED display - green).

Film Advance: With full stroke of 120 degree setting angle and 20 degree standoff position; or several short strokes. Features film feed indicator, and automatic winding capability when used with motor drive or winder system

Film Rewind: Film rewind crank-handle with clutch action, and film rewind release button with automatic resetting

Exposure Counter: Automatically resetting type. Until counter registers "1", camera will automatically set at shutter speed of 1/60 sec. regardless of the setting adjustment on the shutter control dial (except "B" setting).

Multiple Exposures: Enabled by depressing film rewind release button

Accessory Shoe: Direct X contact, and accepts TLA Auto Flash system units.

Camera back: Opens by pulling film rewind knob all the way out. Provided with memo holder. Camera back removable.

Depth-of-Preview Button: Button type that doubles as mechanical shutter release button

Mirror Lock: Lever operated

Power Source: 6.2 V silver-oxide battery (Eveready 544, Ucar 544, Mallory PX28 or equivalent), or 6 V alkaline-manganese battery (4LR44 or equivalent). Provided with a main switch

Battery check: Indicated via steady or pulsating light pattern of LED display in the viewfinder

Other Features: Provided with couplings for motor drive and winder, and with LED for Data Back application.

Manufacturer description #2

The new CONTAX RTS II Quartz represents a quantum leap in Real Time Photography, combining all of the advantages of the original RTS camera with advanced new mechanical and electronics technology to produce a 35mm SLR more accurate, more consistent and more reliable than any other camera in the world.

Most of the improvements in the RTS II Quartz are internal, reflecting more advanced electronics and more reliable mechanical functions. The camera body itself retains the smooth, sleek Porsche design of the RTS, with a few new control points for its enhanced photographic capabilities.

Among the innovations found in the RTS II Quartz are: Quartz Crystal Timing of shutter speeds and all time-related camera functions; Dual SPD exposure metering for full compatibility with the Contax TLA Auto Electronic Flash System, Improved Shutter with Titanium curtains and shaft bearings; Exposure Value-based AE Lock function; Increased Field-of-View to 97% of the total picture area, Digital Viewfinder LED Data Display; Mechanical Shutter Release options at 1/50 sec. and B.

And these new features back up the outstanding Real Time operations retained from the original RTS body, including AE/Manual Mode exposure metering, 1/2000 sec. top shutter speed, Electromagnetic shutter release, Contax/Yashica 3-claw bayonet mount for Carl Zeiss T* lenses and complete integration of all system accessories.

Naturally, all standard Real Time System accessories can be employed with the RTS II Quartz. Improved versions of the Professional Motor Drive (W-6 model) and Real Time Winder (W-3 model) have been specially developed [although previous PMD/RTW units may be used]. A new Quartz Data Back D-4 with remarkably expanded capabilities is available for the RTS II Quartz, along with an upgraded External Power Pack P-3 that offers considerably expanded power capacity. A special new series of interchangeable focusing screens (FS-type) has been introduced in conjunction with the increased 97% field-of view.


Quartz Crystal Timing - The RTS II Quartz now features the same advanced Quartz timing perfected in the Contax 137 MD Quartz and 139 Quartz cameras, assuring exceptional accuracy and total consistency of shutter speeds and all time-related camera functions. The Quartz Crystal Element pulses at a rate of 32,768/second to offer shutter speeds immeasurably more accurate and consistent than any previous mechanical or electronic timing system. The Quartz element also regulates the timing of various operations within the camera body, to improve reliability, durability and consistency of operation.

Dual SPD Exposure Metering - Two Silicon Photo Diode (SPD) cells within the camera body provide instantaneous reaction to even the slightest variation in lighting. One SPD is employed for ambient light exposure measurement, the other for Contax TLA flash exposure control. The SPDs measure center-weighted light patterns, at maximum aperture, for optimum exposure accuracy.

Central Processing Unit - The heart of the RTS II Quartz is a sophisticated C-MOS LSI microprocessing 'chip' which, together with the Quartz Element, comprises the camera's Central Processing Unit. This CPU accepts exposure information in digital values (converted from analog by a Bi-MOS Integrated Circuit) and relays commands to the camera's operating circuitry. The data processing capabilities of this CPU would have required entire rooms of computer equipment just one generation ago; today they are fully integrated on a single flexible circuit board fitting inside the camera body.

AE/Manual Mode Exposure Control - Both AE and Manual operating modes are available with the RTS II Quartz. In the AE Mode, the camera's CPU determines shutter speed automatically, according to the other exposure factors. In the Manual Mode, the camera "recommends" a shutter speed for optimal exposure to the photographer. [AE Mode shutter speeds are stepless within a range of 16 to 1/2000 sec.; Manual Mode shutter speeds range from 4 to 1/2000 sec., and include "B" and "X" (1/60 sec.) settings.]

TLA Auto Flash Compatibility - The RTS II Quartz offers complete compatibility with The Contax TLA flash system, including direct TTL metering of flash exposures at the film plane and 'Fail-Safe' automated control of flash/shutter synchronization. Flash output is metered by an SPD cell, and monitored by the CPU which signals cutoff of the flash when perfect exposure has been achieved. The camera automatically switches between proper X-synch shutter speeds and ambient lighting shutter speeds, depending on the readiness of the TLA unit to fire. AE Lock or Manual Mode use allows setting of shutter speeds slower than the standard 1/60 sec. speed used for X-synch.

Viewfinder LED Data Display - An improved, digital LED data display in the RTS II Quartz viewfinder provides the photographer with full information on Shutter Speeds, Aperture, AE/Manual Mode operation, AE Lock use, Exposure Compensation use, TLA Flash 'Ready' indication, Accurate TLA Flash Exposure, OVER Exposure warning and Battery Check. The LED Display is turned on by pressing the Exposure Check Button on the front of the camera body. After 16 seconds the display cuts off, to conserve battery power, and can be activated again simply by pressing the button once more.

AE Mode shutter speeds are indicated by a steadily-lit LED. Use of the camera's exposure metering system in Manual Mode requires alignment of two LEDs, one steadily lit at the recommended shutter speed, the other flashing at the set shutter speed. Alignment is possible by adjusting either shutter speed or aperture settings.

AE Lock use in AE Mode is indicated by a flashing, rather than steadily-lit shutter speed LED.

In TL A Mode (automatic when TLA unit is attached to camera), a steadily-lit green arrow LED indicates the flash unit is prepared to fire. This LED also operates as a 'confidence light', flickering after a flash exposure if the exposure was correct. [Note: possible over-exposure of scene is indicated by "OVER" LED in all modes.)

Exposure Compensation use is indicated by red +/- LEDs at the bottom of the frame, next to the aperture LED.

Automatic Battery Check is provided by the data display. If the display flickers at slow intervals when turned on, batteries should be replaced.

The viewfinder LED data display also features a special two-stage control which automatically brightens or dims the LED indicators, according to ambient lighting.

AE Lock Function - The AE Lock function of the RTS II Quartz is of a wholly new type, based on Exposure Value factors. Rather than freezing the exposure system at a particular shutter speed, the RTS II Quartz freezes in an Exposure Value, so that any adjustment of aperture will result in automatic adjustment of shutter speed to maintain consistent exposure. This new system is particularly advantageous in providing for photo series, in which exposure is consistent while depth-of-field varies.

Exposure Compensation Function: In order to allow the photographer to vary exposure for creative effect, the RTS II Quartz incorporates an Exposure Compensation Function providing for ±2EV exposure variance, with intermediate click-stops. The main uses of this function are in overcoming moderate back or side-lighting, or as a means of bracketing exposures under difficult lighting conditions.

Improved Shutter - The RTS II Quartz features an entirely new shutter mechanism, with Titanium curtains for improved high-speed accuracy and consistency and increased durability. Only half the weight of standard cloth shutter curtains, these Titanium curtains offer extreme resistance to heat and cold. Six shutter shaft bearings guarantee smoother operation with reduced friction, while a special declutching mechanism frees the shutter itself from the film wind mechanism after cocking, to lighten the running load and eliminate inertial drag. A wedge-shaped shutter brake is highly effective in damping shock, contributing to reduced wear and increased consistency.

Electromagnetic Release - Naturally the RTS II Quartz features the standard Contax electromagnetic shutter release, with its feather-touch 0.7mm stroke and full system compatibility for electronic accessories. In the RTS II Quartz, however, this is backed up by two optional manual mechanical release capabilities. To use the camera at a mechanical 1/50 sec. shutter speed, the photographer turns the Mechanical Shutter Switch Lever to the horizontal position. This turns the Depth-of-Field Preview Button into a mechanical shutter release button for 1/50 sec. operation. The camera can also be used at a mechanical B (Bulb) setting by threading a standard cable release into the mechanical release socket (lower right side of lens mount). This feature is useful in conserving battery power during extremely long exposures (astrophotography, etc.).

97% Field-of-View - In order to prevent the appearance of distracting, unwanted elements in the final image, the RTS II Quartz features a field-of-view increased to 97% of the picture area.

Contax/Yashica Bayonet Mount - The RTS II Quartz offers complete integration with all Carl Zeiss T* lenses and Contax Real Time System optical-path accessories through use of the standard three-claw bayonet lens mount. This rugged, durable stainless steel mount provides optimum linkage between the camera body and either lenses or accessories, and is designed to withstand even long years of hard, professional use.

Quartz Self-Timer - A Quartz-timed, 10-second delay Self-Timer is incorporated into the RTS II Quartz. The Self-Timer can be reset or cancelled at any time during operation, which is indicated by a flashing red LED on the front of the camera body (flashes accelerate during the final two seconds before shutter release).

Auto 1/60 sec. Wind-On - When new film is loaded in the camera and the camera back is closed, a shutter speed of 1/60 sec. is automatically set (AE or Manual Modes, except "B") until film wind to Frame 1 in the counter is reached. This is particularly convenient for the photographer who loads film in the shade, to prevent unduly long AE shutter speeds while winding on to Frame 1. Normal AE or Manual shutter speeds begin with Frame 1.


Other special features of the Contax RTS II Quartz include: a built-in eyepiece shutter, shutter dial locks at A and X positions, a Main Switch controlling all electronic circuitry, a screw-in flash terminal and release socket, a flip-up key for the battery cap (rather than the standard coin-slot type) and a memo-holder on the back cover.


Exclusive accessories for use with the RTS II Quartz include: External Power Pack P-3, Professional Motor Drive (W-6), Real Time Winder (W-3), FS-type Focusing Screens and Data Back Quartz D-4.


All Contax Real Time System accessories integrate fully with the RTS II Quartz camera, including Close-Up/Macro and Off-Camera Control Systems, TLA Auto Flash equipment and Carl Zeiss T* lenses.

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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 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.

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.

Original name

Camera name as indicated on the camera body.


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.