Sigma 28-70mm F/2.8 DG DN | C

Standard zoom lens • Digital era

Abbreviations

DG The lens is designed for 35mm digital cameras but can be also used on APS-C digital cameras.
DN The lens is optimized for cameras with a short flange back distance.
| C Belongs to the Contemporary series lenses.

Features highlight

Fast
Constant
F/2.8
3
ASPH
2
FLD
2
SLD
IF
CFD 0.19m
STM
9 blades
WR mount
FC
⌀67
filters

Specification

Production details:
Announced:February 2021
Production status: In production
Original name:SIGMA 28-70mm 1:2.8 DG DN C
System:-
Optical design:
Focal length range:28mm - 70mm [2.5X zoom ratio]
Speed range:F/2.8 across the focal length range
Maximum format:35mm full frame
Mount and Flange focal distance:Leica L [20mm]
Sony E [18mm]
Diagonal angle of view:75.4° @ 28mm - 34.3° @ 70mm
Lens construction:16 elements in 12 groups
3 ASPH, 2 FLD, 2 SLD
Internal focusing (IF)
On Leica T/TL/CL APS-C [1.53x] cameras:
35mm equivalent focal length range:42.8mm - 107.1mm (in terms of field of view)
35mm equivalent speed range:F/4.3 (in terms of depth of field)
Diagonal angle of view:53.6° @ 28mm - 22.8° @ 70mm
On Sony NEX/a/ZV APS-C [1.53x] cameras:
35mm equivalent focal length range:42.8mm - 107.1mm (in terms of field of view)
35mm equivalent speed range:F/4.3 (in terms of depth of field)
Diagonal angle of view:53.6° @ 28mm - 22.8° @ 70mm
Diaphragm mechanism:
Diaphragm type:Automatic
Aperture control:None; the aperture is controlled from the camera
Number of blades:9 (nine)
Zooming:
Zoom mechanism:Manual
Zoom control:Zoom ring
Zoom type:Rotary
Zooming method:Extends while zooming
Focusing:
Closest focusing distance:0.19m @ 28mm
0.38m @ 70mm
Magnification ratio:1:4.6 at the closest focusing distance @ 70mm
Focusing modes:Autofocus, manual focus
Autofocus motor:Stepping motor
Manual focus control:Focusing ring
Focus mode selector:AF - MF
Manual focus override in autofocus mode:Determined by the camera
Optical Stabilizer (OS):
Built-in OS:-
Physical characteristics:
Weight:470g (Leica L)
470g (Sony E)
Maximum diameter x Length:⌀72.2×101.5mm (Leica L)
⌀72.2×103.5mm (Sony E)
Weather sealing:Water-resistant mount
Fluorine coating:Front element
Accessories:
Filters:Screw-type 67mm
Lens hood:LH706-01 - Bayonet-type petal-shaped
Teleconverters:Not compatible
Source of data:
Manufacturer's technical data.

Manufacturer description

The SIGMA 28-70mm F2.8 DG DN | Contemporary redefines the standard zoom for mirrorless cameras by combining outstanding optical performance, an F2.8 constant aperture, and a lightweight and compact body. The design of the 28-70mm F2.8 DG DN | Contemporary is based on the existing 24-70mm F2.8 DG DN | Art, but with a focal range starting at 28mm, making the lens body significantly smaller and lighter while maintaining superb optical performance. It is the smallest and lightest lens in its class*. Remaining true to the Contemporary line’s core concept of maintaining an optimal balance between optical performance and lens size, this new optic delivers professional quality results in a body small enough to take on a casual outing.

In addition to prioritizing portability, SIGMA’s optical engineers introduced a new combination of coatings and structural elements that make this standard zoom well-equipped for use in a wide range of shooting environments. Likewise, the latest production and manufacturing techniques were employed to ensure exceptionally high build quality.

The 28-70mm F2.8 DG DN | Contemporary introduces another fast, high-performance, large-aperture zoom lens to SIGMA’s mirrorless line-up, offering a more compact alternative to the existing 24-70mm F2.8 DG DN | Art.

The optical design of the SIGMA 28-70mm F2.8 DG DN | Contemporary is based on the 24-70mm F2.8 DG DN | Art, which is renowned for its outstanding optical performance throughout its zoom range. True to the Contemporary line’s core concept, the 28-70mm F2.8 DG DN | Contemporary was developed to offer the right balance of performance and portability, and as such, this large-aperture standard zoom delivers outstanding image quality that rivals Art line lenses in a body light enough for day-to-day use. Building on state-of-the-art technology, the 28-70mm F2.8 DG DN | Contemporary has an advanced optical design that includes three aspherical, two FLD, and two SLD elements. Despite using fewer elements in total than the 24-70mm F2.8 DG DN | Art, the design results in a thorough correction of axial chromatic aberration and sagittal coma aberration, which cannot be corrected in-camera, allowing users to create images that are uniformly sharp from the center to the edges of the frame. Along with its anti-ghosting design, the use of Super Multi-Layer Coating and Nano Porous Coating means well-controlled flare for high-contrast results in backlit conditions. It also features a water and oil repellant coating on the front side of the lens.

In short, the SIGMA 28-70mm F2.8 DG DN | Contemporary combines all of the key optical features required of a large-aperture standard zoom lens, which are essential for photographing a wide variety of subjects in a range of shooting conditions.

With the addition of the new 28-70mm F2.8 DG DN | Contemporary, SIGMA now provides two optimal solutions of standard F2.8 zoom lens for mirrorless cameras ― the new 28-70mm F2.8 DG DN | Contemporary achieves remarkable portability and offers the same optical performance, as the existing 24-70mm F2.8 DG DN | Art which is for pro-use with the highest levels of performance throughout its focal range.

Being slightly less wide-angle than the 24-70mm F2.8 DG DN | Art has allowed a significant reduction in the size of the 28-70mm F2.8 DG DN | Contemporary lens body. In order to fit with the design concept of the Contemporary line, which balances performance with portability, the new lens features a simpler dust- and splash-proof structure and smaller switches. This makes it the smallest and lightest lens in its class*.

The new lens features just one lightweight focusing element, which keeps the AF unit small. This, along with a quiet and fast stepping motor, makes for responsive and near-silent autofocus performance. The 28-70mm F2.8 DG DN | Contemporary weighs in at 470g, and when attached to the SIGMA fp, the entire setup is 890g. The supreme portability afforded by a camera system that weighs less than 1kg gives photographers a huge amount of freedom and flexibility to achieve their creative vision. It’s also a perfect combination for filmmakers looking for a high-performance, lightweight, easy-to-handle camera system that works well with a gimbal and other accessories.

A large-aperture, standard zoom lens that is light and small enough for casual outings, the 28-70mm F2.8 DG DN | Contemporary will open up new photographic possibilities for better and more creative results.

With priority given to optimal portability, the body of the SIGMA 28-70mm F2.8 DG DN | Contemporary consists primarily of lightweight parts. While conventional wisdom states that it is more difficult to ensure processing accuracy for plastic parts than metal parts, there has been no compromise whatsoever on build quality for the 28-70mm F2.8 DG DN | Contemporary. One reason for this is that it uses a type of polycarbonate called TSC (Thermally Stable Composite), which has a comparable level of thermal shrinkage to aluminum. This helps reduce differences between the thermal shrinkage of the metal and non-metal parts, ensuring stable levels of performance even in an environment with extreme temperature changes. The use of polycarbonates in the construction of zoom and focus rings can make their operation feel less premium, but with careful treatment to the precision of these parts and adjusting the movement with the lubricant appropriately, the rings offer a precise action with an exceptionally high-quality feel. What allows us to achieve these precisely produced parts and such premium aesthetics is the impressive standard of manufacturing technology and rigorous quality control we have at the SIGMA Aizu Factory. The SIGMA 28-70mm F2.8 DG DN | Contemporary offers a new and improved photographic experience for mirrorless users who require a fast aperture standard zoom lens. Its premium, intuitive build makes it as exciting to use the lens as it is to see the incredible images it can produce, inspiring you to start achieving your creative potential.

From the editor

The narrower the focal length range, the more compact and lightweight zoom lenses with simpler optical design can be developed. Guided by this approach, Sigma released the 28-70/2.8 model, which, although it does not offer the same wide field of view as the 24-70/2.8 models, weighs almost 2 times less and retains the speed of 2.8 throughout the entire focal length range. On the other hand, even the field of view of 24-70 models is often insufficient for capturing vast landscapes, cramped interiors, tall/wide buildings, and with the 28-70/2.8 lens, shooting such subjects becomes even more problematic - especially in cases when it is not possible to increase the focusing distance for some reasons. Besides, this Sigma lens is not an obvious choice for owners of Sony E-mount cameras, as it has a strong competitor in the form of the Tamron 28-75/2.8 lens with its larger telephoto range and water-resistant barrel.

In general, the release of this model is rather unjustified in our opinion. However, on the other hand, the fiercer the competition among lens manufacturers and the wider the choice, the more enthusiasts will ultimately benefit from this.

Lenses with similar focal length range

Sorted by manufacturer name

Leica L mount 3 lenses (1 third-party)
Leica Vario-ELMARIT-SL 24-70mm F/2.8 ASPH. E82Pro 2021 Compare23
Panasonic LUMIX S Pro 24-70mm F/2.8 ⌀82Pro 2019 Compare24
Sigma 24-70mm F/2.8 DG DN | A ⌀82Pro 2019 Compare23
Sony E mount 8 lenses (4 third-party)
Samyang AF 24-70mm F/2.8 FE ⌀82
aka Rokinon AF 24-70mm F/2.8 FE
Pro 2021 Compare24
Sigma 24-70mm F/2.8 DG DN | A ⌀82Pro 2019 Compare23
Sony FE 28-70mm F/3.5-5.6 OSS [SEL2870] ⌀55 2013 Compare33
Sony FE Carl Zeiss Vario-Tessar T* 24-70mm F/4 ZA OSS [SEL2470Z] ⌀67Pro 2013 Compare23
Sony FE 24-70mm F/2.8 GM [SEL2470GM] ⌀82Pro 2016 Compare24
Sony FE 24-70mm F/2.8 GM II [SEL2470GM2] ⌀82Pro 2022 Compare22
Tamron 28-75mm F/2.8 Di III RXD A036 ⌀67Pro 2018 Compare11
Tamron 28-75mm F/2.8 Di III VXD G2 A063 ⌀67Pro 2021 Compare10
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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.

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.

Stepping motor

Stepping motor

AF - MF

AFAutofocus mode.
MFManual focus mode.

Aspherical elements

Aspherical elements (ASPH, XA, XGM) are used in wide-angle lenses for correction of distortion and in large-aperture lenses for correction of spherical aberration, astigmatism and coma, thus ensuring excellent sharpness and contrast even at fully open aperture. The effect of the aspherical element is determined by its position within the optical formula: the more the aspherical element moves away from the aperture stop, the more it influences distortion; close to the aperture stop it can be particularly used to correct spherical aberration. Aspherical element can substitute one or several regular spherical elements to achieve similar or better optical results, which allows to develop more compact and lightweight lenses.

Use of aspherical elements has its downsides: it leads to non-uniform rendering of out-of-focus highlights. This effect usually appears as "onion-like" texture of concentric rings or "wooly-like" texture and is caused by very slight defects in the surface of aspherical element. It is difficult to predict such effect, but usually it occurs when the highlights are small enough and far enough out of focus.

Low dispersion elements

Low dispersion elements (ED, LD, SD, UD etc) minimize chromatic aberrations and ensure excellent sharpness and contrast even at fully open aperture. This type of glass exhibits low refractive index, low dispersion, and exceptional partial dispersion characteristics compared to standard optical glass. Two lenses made of low dispersion glass offer almost the same performance as one fluorite lens.

Low dispersion elements

Low dispersion elements (ED, LD, SD, UD etc) minimize chromatic aberrations and ensure excellent sharpness and contrast even at fully open aperture. This type of glass exhibits low refractive index, low dispersion, and exceptional partial dispersion characteristics compared to standard optical glass. Two lenses made of low dispersion glass offer almost the same performance as one fluorite lens.

Canon's Super UD, Nikon's Super ED, Pentax' Super ED, Sigma's FLD ("F" Low Dispersion), Sony' Super ED and Tamron's XLD glasses are the highest level low dispersion glasses available with extremely high light transmission. These optical glasses have a performance equal to fluorite glass.

High-refraction low-dispersion elements

High-refraction low-dispersion elements (HLD) minimize chromatic aberrations and ensure excellent sharpness and contrast even at fully open aperture.

High Index, High Dispersion elements

High Index, High Dispersion elements (HID) minimize chromatic aberrations and ensure excellent sharpness and contrast even at fully open aperture.

Anomalous partial dispersion elements

Anomalous partial dispersion elements (AD) minimize chromatic aberrations and ensure excellent sharpness and contrast even at fully open aperture.

Fluorite elements

Synthetic fluorite elements (FL) minimize chromatic aberrations and ensure excellent sharpness and contrast even at fully open aperture. Compared with optical glass, fluorite lenses have a considerably lower refraction index, low dispersion and extraordinary partial dispersion, and high transmission of infrared and ultraviolet light. They are also significantly lighter than optical glass.

According to Nikon, fluorite easily cracks and is sensitive to temperature changes that can adversely affect focusing by altering the lens' refractive index. To avoid this, Canon, as the manufacturer most widely using fluorite in its telephoto lenses, never uses fluorite in the front and rear lens elements, and the white coating is applied to the lens barrels to reflect light and prevent the lens from overheating.

Short-wavelength refractive elements

High and specialized-dispersion elements (SR) refract light with wavelengths shorter than that of blue to achieve highly precise chromatic aberration compensation. This technology also results in smaller and lighter lenses.

Blue Spectrum Refractive Optics

Organic Blue Spectrum Refractive Optics material (BR Optics) placed between convex and concave elements made from conventional optical glass provides more efficient correction of longitudinal chromatic aberrations in comparison with conventional technology.

Diffraction elements

Diffraction elements (DO, PF) cancel chromatic aberrations at various wavelengths. This technology results in smaller and lighter lenses in comparison with traditional designs with no compromise in image quality.

High refractive index elements

High refractive index elements (HR, HRI, XR etc) minimize field curvature and spherical aberration. High refractive index element can substitute one or several regular elements to achieve similar or better optical results, which allows to develop more compact and lightweight lenses.

Apodization element

Apodization element (APD) is in fact a radial gradient filter. It practically does not change the characteristics of light beam passing through its central part but absorbs the light at the periphery. It sort of softens the edges of the aperture making the transition from foreground to background zone very smooth and results in very attractive, natural looking and silky smooth bokeh.

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.

Fixed focus

There is no helicoid in this lens and everything is in focus from the closest focusing distance to infinity.

Internal focusing (IF)

Conventional lenses employ an all-group shifting system, in which all lens elements shift during focusing. The IF system, however, shifts only part of the optics during focusing. The advantages of the IF system are:

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/2.8 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.

Rotary zoom

The change of focal length is achieved by turning the zoom ring and the manual focusing - by turning the separate focusing ring.

Push/pull zooming allows for faster change of focal length, however conventional method based on the rotation of the zoom ring provides more accurate and smooth zooming.

Push/pull zoom

The change of focal length happens when the photographer moves the ring towards the mount or backwards.

Push/pull zooming allows for faster change of focal length, however conventional method based on the rotation of the zoom ring provides more accurate and smooth zooming.

Zoom lock

The lens features a zoom lock to keep the zoom ring fixed. This function is convenient for carrying a camera with the lens on a strap because it prevents the lens from extending.

Zoom clutch

To set the manual zoom mode, pull the zoom ring towards the camera side until the words "POWER ZOOM" disappear.