Pentax *ist

35mm AF film SLR camera



Production details:
Announced:April 2003
System: Pentax K (1975)
Maximum format:35mm full frame
Film type:135 cartridge-loaded film
Mount and Flange focal distance:Pentax K [45.5mm]
Model:Electronically controlled
Speeds:30 - 1/4000 + B
Exposure metering:Through-the-lens (TTL), open-aperture
Exposure modes:Programmed Auto
Aperture-priority Auto
Shutter-priority Auto
Physical characteristics:

Manufacturer description #1

PENTAX Corporation is pleased to announce the marketing of the PENTAX *ist 35mm autofocus SLR camera.

Encased in the world's smallest in the 35mm autofocus SLR category *, this new SLR incorporates a host of advanced features and user-friendly functions to facilitate easy operation and assure greater creativity. They include: a multi-mode exposure system with the innovative Auto Picture mode and an accessible illumination mode dial; a 16-segment multi-pattern metering system; a 11-point autofocus system; a 1/4000-second high-speed shutter; 17 custom functions; a large LCD panel; a multi-data LCD viewfinder indicator; and a retractable auto pop-up flash. It also accepts a full range of high-quality smc PENTAX interchangeable lenses and accessories - including two new zoom lenses and the new BG-20 battery grip - to maximize the fun and excitement of advanced SLR photography.

Combining the highest level of quality and performance with super-compact dimensions and user-friendly operation and display systems, the PENTAX *ist is fully capable of satisfying a wide range of photographers - from the most demanding professionals and experienced amateurs to SLR novices. It is expected to become a new standard-setter in the highly competitive global 35mm SLR market.

Major Features of the PENTAX *ist

1. Ultra-compact dimensions and functional design

Measuring only 122mm wide, 84mm high and 63.5mm thick (4.8 x 3.3 x 2.5 inches) and weighing a mere 335 grams (11.8 oz.), the new *ist features the world's smallest in the 35mm autofocus SLR market. All controls are functionally positioned on the top and back panels for maximum ease of operation and accessibility.

2. High-precision 16-segment multi-pattern metering system with user-selectable spot and center-weighted modes

The newly developed 16-segment multi-pattern metering system solves even the most complicated lighting conditions to produce beautifully exposure photographs, frame after frame. In addition to all-purpose multi-pattern mode, the *ist also offers spot and center-weighted modes to meet specialized applications.

3. Sophisticated 11-point autofocus system with cross-shaped AF point selector and LED viewfinder indicator

Thanks to the advanced SAFOX VIII phase-matching autofocus system, the *ist assures sharp, crisp focus on the subject, even under poor lighting conditions. Its newly developed 11-point AF sensor constantly monitors 11 different points in the image field and covers a wide area - both vertically and horizontally - to assure optimum focus. In addition to the "AUTO" mode - where the camera automatically selects the optimum focusing point - and the "SPOT" mode - where the focus area is narrowed down to a small area at the center of the image field - the *ist also offers the innovative "SELECT" mode, where the user can select one of 11 AF sensor points using the cross-shaped AF point selector on the back panel. What's more, the selected AF sensor point is confirmed by an LED pointer in the viewfinder. This sophisticated AF system also features the predictive autofocus function, which is automatically activated when the system detects subject motion and predicts the subject position at the moment of shutter release. This function even allows the photographer to shoot a few frames after the subject has moved out of the AF sensor field.

4. Auto Picture mode and illumination mode dial

When the Auto Picture Mode is selected, the *ist automatically selects the most appropriate auto-exposure mode from five different programs, based on such data as the subject's distance, lens focal length, lighting conditions and subject motion. This not only ensures the best possible result for every subject and in every situation, but also allows the photographer to concentrate completely on shutter opportunity and picture-framing. The large illumination mode dial clearly indicates the selected exposure program, even in the dark. The selected program is also indicated in the viewfinder indicator.

5. Multi-mode exposure system

In addition to the Auto Picture Mode, the *ist offers six user-selectable Picture Modes, two conventional auto-exposure modes (Aperture-Priority AE and Shutter-Priority AE), Metered Manual mode and bulb mode.

6. Multi-function retractable auto flash with auto pop-up feature

Covering an angle of view as wide as 28mm, the auto flash automatically pops up and discharges when the camera detects low-light and/or backlight situations. It also retracts to the storage position automatically when the camera's power is turned off. Its red-eye reduction function effectively reduces the annoying red-eye effect in subjects' eyes.* Thanks to the advanced TTL flash control system, complicated flash techniques (such as daylight sync, slow-shutter sync and bulb sync) are made simple and effortless, even when used in combination with accessory flash units. Especially when combined with the AF360FGZ, it offers a variety of advanced wireless remote functions. In addition, it even makes a brief discharge in the dark to assist the camera's AF system.

* This mode does not eliminate "red eyes" in all instances.

7. 1/4000-second high-speed shutter with 1/125-second flash synchronization

The compact, reliable shutter unit offers a top shutter speed of 1/4000 second to freeze the decisive moment of fast-action scenes. It also features a high flash synchronization speed of 1/125 second, so that the photographer can open up the aperture to capture dramatic flash images.

8. User-adjustable custom functions

The *ist offers 17 custom functions, enabling the photographer to customize some basic camera functions to suit individual preferences. These functions include the AF pointer display in the viewfinder, the LED illuminator operation mode in the LCD panel, the order of exposures in the auto bracketing mode, and the timing of remote shutter release.

9. Large, easy-to-read LCD data panel with automatic illuminator

Located on the back panel, the multi-data LCD panel offers a full range of information with large icons and numbers to supplement the camera's user-friendly operation system. The user can activate its orange LED illuminator by turning the main switch to the preview position. Using one of the custom functions, it is also possible to select automatic illumination under low-light conditions or deactivate the illuminator at all times.

10. Bright viewfinder with full-information LCD viewfinder indicator and AF pointer

Thanks to the renowned Natural-Bright-Matte focusing screen, the *ist offers a sharp, clear viewfinder image even under unfavorable lighting conditions. The LCD viewfinder indicator at the bottom provides a full range of information, including the selected Picture Mode and exposure compensation factors. For easy data confirmation, it even comes equipped with automatic brightness control, which changes the brightness level in proportion to the subject's lighting condition. Within its image field, the viewfinder features LED AF pointers, one of which lights up to indicate the user-selected AF sensor. The diopter adjustment mechanism built into the viewfinder eyepiece allows the user to adjust the viewfinder image between -2.0m-1 and +1.0m-1 to obtain the clearest view of the subject.

11. 2.5-frame-per-second high-speed motor drive

The high-speed motor drive winds the film at a speed of 2.5 frames per second. The user can select either single-frame advance or consecutive advance with simple pushbutton operation. It also simplifies film loading and rewinding operations.

12. Effortless auto bracketing

With a single shutter release, the photographer can capture three different exposures of the same subject (in order of proper exposure, underexposure and overexposure) in all exposure modes (except Bulb mode). The desired compensation value (±0.3EV, ±0.5EV or ±1.0EV) can be selected using one of the custom functions. The use of auto bracketing as well as the selected compensation value are indicated in both the LCD panel and the viewfinder display.

13. Easy-setting exposure compensation and AE lock

Using the exposure compensation button and the select dial, the photographer can easily set the desired compensation value within a range of ±3EV in 1/2EV increments (except when the Metered Manual mode is selected). Positioned at the upper right-hand corner of the back panel, the AE lock button makes the camera memorize the measured exposure value for approximately 20 seconds, during which period the photographer is free to re-compose the image.

14. Creative multi-exposure

The photographer can make two exposures on a single frame with pushbutton ease to produce dramatic, eye-catching images. To expose the same frame more than three times, the photographer simply needs to repeat this operation after each exposure.

15. Depth-of-field preview

The depth-of-field preview function is electronically operated for easy confirmation of the in-focus area in the image field before actually taking a picture. It allows the photographer to create the desired visual effect more consistently.

16. Handy wireless remote control

In combination with the accompanying remote controller, the *ist offers the convenience of remote shutter release from a distance. The user can select either an instant release or a three-second-delay release using one of the custom functions. The operation is confirmed by the self-timer indicator on the camera's front panel.

17. Durable metallic lens mount

The *ist features a durable metallic lens mount to minimize wear caused by countless lens changes over years and always hold the lens firmly in place.

18. Data recording capability

The *ist allows the user to automatically record the date, or day and time, of picture-taking on the photograph for quick, easy reference of captured images.

19. High-performance smc PENTAX 35mm lens system

PENTAX offers a selection of PENTAX FA- and F-series autofocus lenses for use with the *ist to meet the diverse requirements of its users, from ultra-wide angle to super telephoto, and to special-effect lenses such as fish-eye, macro and soft-focus. To minimize the overall size of the *ist with a lens attached, PENTAX developed two compact, high-performance zoom lenses as ideal partners for the *ist: the smc Pentax-FA J Zoom 28mm~80mm F3.5~F5.6 AL and the smc Pentax-FA J Zoom 75mm~300mm F4.5~F5.8 AL. All smc PENTAX lenses are treated with the acclaimed Super-Multi-Coating to reproduce sharp, high-contrast images with minimal aberrations.

20. A wide range of optional accessories

Most existing PENTAX 35mm-system accessories can be used with the *ist, including the AF360FGZ dedicated flash unit. In addition, the new BG-20 battery grip, which is exclusively designed for use with the *ist, is powered by four AA-size batteries to greatly extend the camera's operation time; it features an enlarged grip and a vertical-position shutter release button.

Manufacturer description #2

Simple Operation with Innovative Auto Picture Mode

The PENTAX *ist offers a selection of sophisticated and user-friendly features designed to simplify camera operations and make high-quality SLR photography more enjoyable and flexible. Its innovative, versatile Auto Picture mode, for instance, automatically selects the best exposure program for a given subject from five distinctive Picture Programs — Portrait, Action, Landscape, Close-Up and Standard — while indicating the selected program on the illumination mode dial and in the viewfinder display for at-a-glance confirmation. Accessible dials on the top panel and a user-friendly four-way controller on the back also contribute to swift and simplified operation.

Ultra-Compact, Super-Lightweight Body with Eye-Catching Design

After a complete review of body design and mechanical layout, PENTAX successfully created the most compact, lightweight body in its 35mm-format autofocus SLR lineup for the *ist — without sacrificing performance or operability.

High-Precision 16-Segment Multi-Pattern Metering for Unfailing Exposure Control

Incorporating the newly developed 16-segment multi-pattern metering system, the *ist assures high-precision metering even under difficult, confusing lighting conditions. You can also switch to conventional center-weighted metering or pinpoint spot metering to deal with special situations.

Sophisticated 11-Point Autofocus Featuring SAFOX VIII

Featuring the advanced SAFOX VIII phase-matching autofocus system, the *ist automatically selects the optimal focusing point using 11 AF sensors to assure sharp, crisp focus on a wide range of subjects. In addition to the versatile 11-point autofocus mode, which comes in handy when a subject is positioned off center or two subjects stand side by side, the *ist also offers the spot AF mode to assure pinpoint focus on a single, small element of the subject, and the SELECT mode to choose any one of the 11 AF sensor points using the four-way controller for a specific image composition. In the SELECT mode, you can even confirm the selected AF sensor point with a red LED indicator in the viewfinder for precise positioning of the subject. The desired mode can be easily selected with simple switch operation.

Extra-Compact Shutter Unit with 1/4000-Second Top Speed

The *ist incorporates a newly designed super-compact shutter unit with a top shutter speed of 1/4000 second, which allows you to capture the decisive moment of a subject in motion. This reliable, functional shutter unit also offers high-speed flash synchronization at 1/125 second, letting you use larger apertures for more dramatic flash images — especially in close-up and macro applications.

Large, Easy-to-Read LCD Panel with LED Illumination

The large multi-data LCD panel on the back provides a comprehensive range of photographic information via large icons and digits. It also comes equipped with orange-colored LED illumination for easy data reading in the dark.

Auto Bracketing for Simplified Exposure Adjustment

The convenient auto bracketing function allows you to take three frames of the same subject at three different exposures (under, normal and over).

An Array of Flash Functions for Creative Flash Photography

In combination with the optional AF360FGZ dedicated flash unit, the *ist offers a range of creative flash functions, including synchronization with all shutter speeds, wireless remote control, high-speed sync flash, and contrast-control flash.

Functional Design with Superb Operability and Maneuverability

All control devices, such as dials, buttons and four-way controller, as well as the large LCD panel, are efficiently and accessibly laid out on the compact, stylish body to ensure exceptional operability and maneuverability.

User-Adjustable Custom Functions to Personalize Operations

The *ist's custom function feature lets you preprogram 17 basic camera functions to suit your preferences and minimize delays and errors while shooting.

Other Outstanding Features

  • High-speed consecutive shooting at approximately 2.5 frames per second
  • AE lock to memorize an exposure value before shutter release
  • Easy-to-read LCD viewfinder indicator offering a wide range of information underneath the image field
  • Electronic preview for at-a-glance depth-of-field confirmation through the viewfinder
  • Bright, clear viewfinder with built-in diopter adjuster
  • Wireless infrared remote control for instant or 3-second-delay shutter release from a distance (in combination with the optional remote controller)
  • Built-in auto flash that automatically pops up for discharge in low-light and backlight conditions, then returns to storage position at power off
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Chromatic aberration

There are two kinds of chromatic aberration: longitudinal and lateral. Longitudinal chromatic aberration is a variation in location of the image plane with changes in wave lengths. It produces the image point surrounded by different colors which result in a blurred image in black-and-white pictures. Lateral chromatic aberration is a variation in image size or magnification with wave length. This aberration does not appear at axial image points but toward the surrounding area, proportional to the distance from the center of the image field. Stopping down the lens has only a limited effect on these aberrations.

Spherical aberration

Spherical aberration is caused because the lens is round and the film or image sensor is flat. Light entering the edge of the lens is more severely refracted than light entering the center of the lens. This results in a blurred image, and also causes flare (non-image forming internal reflections). Stopping down the lens minimizes spherical aberration and flare, but introduces diffraction.


Astigmatism in a lens causes a point in the subject to be reproduced as a line in the image. The effect becomes worse towards the corner of the image. Stopping down the lens has very little effect.


Coma in a lens causes a circular shape in the subject to be reproduced as an oval shape in the image. Stopping down the lens has almost no effect.

Curvature of field

Curvature of field is the inability of a lens to produce a flat image of a flat subject. The image is formed instead on a curved surface. If the center of the image is in focus, the edges are out of focus and vice versa. Stopping down the lens has a limited effect.


Distortion is the inability of a lens to capture lines as straight across the entire image area. Barrel distortion causes straight lines at the edges of the frame to bow toward the center of the image, producing a barrel shape. Pincushion distortion causes straight lines at the edges of the frame to curve in toward the lens axis. Distortion, whether barrel or pincushion type, is caused by differences in magnification; stopping down the lens has no effect at all.

The term "distortion" is also sometimes used instead of the term "aberration". In this case, other types of optical aberrations may also be meant, not necessarily geometric distortion.


Classically, light is thought of as always traveling in straight lines, but in reality, light waves tend to bend around nearby barriers, spreading out in the process. This phenomenon is known as diffraction and occurs when a light wave passes by a corner or through an opening. Diffraction plays a paramount role in limiting the resolving power of any lens.


Doublet is a lens design comprised of two elements grouped together. Sometimes the two elements are cemented together, and other times they are separated by an air gap. Examples of this type of lens include achromatic close-up lenses.

Dynamic range

Dynamic range is the maximum range of tones, from darkest shadows to brightest highlights, that can be produced by a device or perceived in an image. Also called tonal range.

Resolving power

Resolving power is the ability of a lens, photographic emulsion or imaging sensor to distinguish fine detail. Resolving power is expressed in terms of lines per millimeter that are distinctly recorded in the final image.


Vignetting is the darkening of the corners of an image relative to the center of the image. There are three types of vignetting: optical, mechanical, and natural vignetting.

Optical vignetting is caused by the physical dimensions of a multi-element lens. Rear elements are shaded by elements in front of them, which reduces the effective lens opening for off-axis incident light. The result is a gradual decrease of the light intensity towards the image periphery. Optical vignetting is sensitive to the aperture and can be completely cured by stopping down the lens. Two or three stops are usually sufficient.

Mechanical vignetting occurs when light beams are partially blocked by external objects such as thick or stacked filters, secondary lenses, and improper lens hoods.

Natural vignetting (also known as natural illumination falloff) is not due to the blocking of light rays. The falloff is approximated by the "cosine fourth" law of illumination falloff. Wide-angle rangefinder designs are particularly prone to natural vignetting. Stopping down the lens cannot cure it.


Bright shapes or lack of contrast caused when light is scattered by the surface of the lens or reflected off the interior surfaces of the lens barrel. This is most often seen when the lens is pointed toward the sun or another bright light source. Flare can be minimized by using anti-reflection coatings, light baffles, or a lens hood.


Glowing patches of light that appear in a photograph due to lens flare.

Retrofocus design

Design with negative lens group(s) positioned in front of the diaphragm and positive lens group(s) positioned at the rear of the diaphragm. This provides a short focal length with a long back focus or lens-to-film distance, allowing for movement of the reflex mirror in SLR cameras. Sometimes called an inverted telephoto lens.

Rectilinear design

Design that does not introduce significant distortion, especially ultra-wide angle lenses that preserve straight lines and do not curve them (unlike a fisheye lens, for instance).

Focus shift

A change in the position of the plane of optimal focus, generally due to a change in focal length when using a zoom lens, and in some lenses, with a change in aperture.


The amount of light that passes through a lens without being either absorbed by the glass or being reflected by glass/air surfaces.

Modulation Transfer Function (MTF)

When optical designers attempt to compare the performance of optical systems, a commonly used measure is the modulation transfer function (MTF).

The components of MTF are:

The MTF of a lens is a measurement of its ability to transfer contrast at a particular resolution from the object to the image. In other words, MTF is a way to incorporate resolution and contrast into a single specification.

Knowing the MTF curves of each photographic lens and camera sensor within a system allows a designer to make the appropriate selection when optimizing for a particular resolution.

Veiling glare

Lens flare that causes loss of contrast over part or all of the image.

Anti-reflection coating

When light enters or exits an uncoated lens approximately 5% of the light is reflected back at each lens-air boundary due to the difference in refractive index. This reflected light causes flare and ghosting, which results in deterioration of image quality. To counter this, a vapor-deposited coating that reduces light reflection is applied to the lens surface. Early coatings consisted of a single thin film with the correct refractive index differences to cancel out reflections. Multi-layer coatings, introduced in the early 1970s, are made up of several such films.

Benefits of anti-reflection coating:

Circular fisheye

Produces a 180° angle of view in all directions (horizontal, vertical and diagonal).

The image circle of the lens is inscribed in the image frame.

Diagonal (full-frame) fisheye

Covers the entire image frame. For this reason diagonal fisheye lenses are often called full-frame fisheyes.

Extension ring

Extension rings can be used singly or in combination to vary the reproduction ratio of lenses. They are mounted between the camera body and the lens. As a rule, the effect becomes stronger the shorter the focal length of the lens in use, and the longer the focal length of the extension ring.

View camera

A large-format camera with a ground-glass viewfinder at the image plane for viewing and focusing. The photographer must stick his head under a cloth hood in order to see the image projected on the ground glass. Because of their 4x5-inch (or larger) negatives, these cameras can produce extremely high-quality results. View cameras also usually support movements.

135 cartridge-loaded film

43.27 24 36
  • Introduced: 1934
  • Frame size: 36 × 24mm
  • Aspect ratio: 3:2
  • Diagonal: 43.27mm
  • Area: 864mm2
  • Double perforated
  • 8 perforations per frame

120 roll film

71.22 44 56
  • Introduced: 1901
  • Frame size: 56 × 44mm
  • Aspect ratio: 11:14
  • Diagonal: 71.22mm
  • Area: 2464mm2
  • Unperforated

120 roll film

79.2 56 56
  • Introduced: 1901
  • Frame size: 56 × 56mm
  • Aspect ratio: 1:1
  • Diagonal: 79.2mm
  • Area: 3136mm2
  • Unperforated

120 roll film

89.64 56 70
  • Introduced: 1901
  • Frame size: 70 × 56mm
  • Aspect ratio: 5:4
  • Diagonal: 89.64mm
  • Area: 3920mm2
  • Unperforated

220 roll film

71.22 44 56
  • Introduced: 1965
  • Frame size: 56 × 44mm
  • Aspect ratio: 11:14
  • Diagonal: 71.22mm
  • Area: 2464mm2
  • Unperforated
  • Double the length of 120 roll film

220 roll film

79.2 56 56
  • Introduced: 1965
  • Frame size: 56 × 56mm
  • Aspect ratio: 1:1
  • Diagonal: 79.2mm
  • Area: 3136mm2
  • Unperforated
  • Double the length of 120 roll film

220 roll film

89.64 56 70
  • Introduced: 1965
  • Frame size: 70 × 56mm
  • Aspect ratio: 5:4
  • Diagonal: 89.64mm
  • Area: 3920mm2
  • Unperforated
  • Double the length of 120 roll film

Shutter speed ring with "F" setting

The "F" setting disengages the leaf shutter and is set when using only the focal plane shutter in the camera body.

Catch for disengaging cross-coupling

The shutter and diaphragm settings are cross-coupled so that the diaphragm opens to a corresponding degree when faster shutter speeds are selected. The cross-coupling can be disengaged at the press of a catch.

Cross-coupling button

With the cross-coupling button depressed speed/aperture combinations can be altered without changing the Exposure Value setting.

M & X sync

The shutter is fully synchronized for M- and X-settings so that you can work with flash at all shutter speeds.

In M-sync, the shutter closes the flash-firing circuit slightly before it is fully open to catch the flash at maximum intensity. The M-setting is used for Class M flash bulbs.

In X-sync, the flash takes place when the shutter is fully opened. The X-setting is used for electronic flash.

X sync

The shutter is fully synchronized for X-setting so that you can work with flash at all shutter speeds.

In X-sync, the flash takes place when the shutter is fully opened. The X-setting is used for electronic flash.

Unable to follow the link

You are already on the page dedicated to this lens.

Cannot perform comparison

Cannot compare the lens to itself.

Image stabilizer

A technology used for reducing or even eliminating the effects of camera shake. Gyro sensors inside the lens detect camera shake and pass the data to a microcomputer. Then an image stabilization group of elements controlled by the microcomputer moves inside the lens and compensates camera shake in order to keep the image static on the imaging sensor or film.

The technology allows to increase the shutter speed by several stops and shoot handheld in such lighting conditions and at such focal lengths where without image stabilizer you have to use tripod, decrease the shutter speed and/or increase the ISO setting which can lead to blurry and noisy images.

Original name

Lens name as indicated on the lens barrel (usually on the front ring). With lenses from film era, may vary slightly from batch to batch.


Format refers to the shape and size of film or image sensor.

35mm is the common name of the 36x24mm film format or image sensor format. It has an aspect ratio of 3:2, and a diagonal measurement of approximately 43mm. The name originates with the total width of the 135 film which was the primary medium of the format prior to the invention of the full frame digital SLR. Historically the 35mm format was sometimes called small format to distinguish it from the medium and large formats.

APS-C is an image sensor format approximately equivalent in size to the film negatives of 25.1x16.7mm with an aspect ratio of 3:2.

Medium format is a film format or image sensor format larger than 36x24mm (35mm) but smaller than 4x5in (large format).

Angle of view

Angle of view describes the angular extent of a given scene that is imaged by a camera. It is used interchangeably with the more general term field of view.

As the focal length changes, the angle of view also changes. The shorter the focal length (eg 18mm), the wider the angle of view. Conversely, the longer the focal length (eg 55mm), the smaller the angle of view.

A camera's angle of view depends not only on the lens, but also on the sensor. Imaging sensors are sometimes smaller than 35mm film frame, and this causes the lens to have a narrower angle of view than with 35mm film, by a certain factor for each sensor (called the crop factor).

This website does not use the angles of view provided by lens manufacturers, but calculates them automatically by the following formula: 114.6 * arctan (21.622 / CF * FL),


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


A lens mount is an interface — mechanical and often also electrical — between a camera body and a lens.

A lens mount may be a screw-threaded type, a bayonet-type, or a breech-lock type. Modern camera lens mounts are of the bayonet type, because the bayonet mechanism precisely aligns mechanical and electrical features between lens and body, unlike screw-threaded mounts.

Lens mounts of competing manufacturers (Canon, Nikon, Pentax, Sony etc.) are always incompatible. In addition to the mechanical and electrical interface variations, the flange focal distance can also be different.

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

Lens construction

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

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

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

Focal length

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


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

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

Closest focusing distance

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

Closest working distance

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

Magnification ratio

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

Manual focus override in autofocus mode

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

Manual focus override in autofocus mode

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

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

Manual diaphragm

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

Preset diaphragm

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

Semi-automatic diaphragm

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

Automatic diaphragm

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

Fixed diaphragm

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

Number of blades

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

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

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


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

Maximum diameter x Length

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

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

Weather sealing

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

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

Fluorine coating

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


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

Lens hood

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

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

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

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


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

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

Lens caps

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