Carl Zeiss Planar [T*] 100mm F/3.5 C

Standard prime lens • Film era • Discontinued

Abbreviations

T* Multi-layer anti-reflection coating is applied to the surfaces of lens elements. This anti-reflection coating increases light transmission, eliminates flare and ghosting, and maintains color consistence among all lens models.
C A lens with Compur shutter.

Model history (3)

Carl Zeiss Planar [T*] 100mm F/3.5 CA5 - 40.90mB50 1968 
Carl Zeiss Planar T* 100mm F/3.5 C
Carl Zeiss Planar T* 100mm F/3.5 CFA5 - 40.90mB60 1982 
Carl Zeiss Planar T* 100mm F/3.5 CFiA5 - 40.90mB60 1998 

Features highlight

6x6
LS
MF
Auto
Compact
B50
filters
TC

Specification

Production details:
Announced:1968
Production status: Discontinued
Original name:Carl Zeiss Planar 1:3,5 f=100mm
Carl Zeiss Planar 1:3,5 f=100mm T*
System:Hasselblad V (1957)
Optical design:
Focal length:100mm
Speed:F/3.5
Maximum format:Medium format 6x6
Mount and Flange focal distance:Hasselblad V [74.9mm]
Diagonal angle of view:42.9°
Lens construction:5 elements in 4 groups
Diaphragm mechanism:
Diaphragm type:Automatic
Aperture control:Aperture ring (Manual settings only)
Built-in leaf shutter:
Type:Mechanical Synchro-Compur
Range of shutter speeds:1 - 1/500 + B
Self-timer (V):Yes
Shutter speed control:Shutter speed ring
Cross-coupling control:Catch for disengaging cross-coupling
Flash sync mode:M & X sync
Flash sync terminal:Yes
Focusing:
Closest focusing distance:0.9m
Magnification ratio:<No data>
Focusing modes:Manual focus only
Manual focus control:Focusing ring
Physical characteristics:
Weight:610g
Maximum diameter x Length:⌀78×62mm
Accessories:
Filters:Bayonet-type 50
Lens hood:Ø50/100-250 40126 - Bayonet-type square
Teleconverters:Carl Zeiss PC Mutar T* 1.4X → 140mm F/4.9
Hasselblad Teleconverter 1.4XE → 140mm F/4.9
Carl Zeiss Mutar T* 2X → 200mm F/7
Hasselblad Converter 2XE → 200mm F/7
Sources of data:
1. Manufacturer's technical data.
2. Hasselblad 500EL/M, SWC/M, 2000FC, 500C/M booklet (December 1980).
3. Hasselblad Product Catalog (November 1977).
4. Hasselblad 500EL/M, SWC, 2000FC, 500C/M booklet (December 1977).
5. Hasselblad Product Catalog (December 1978).
6. Hasselblad Product Catalog (December 1979).
7. Hasselblad Product Catalog 1983/84 (December 1982).
8. Hasselblad Product Catalog (December 1968).

Manufacturer description #1

The Planar T* f/3.5-100 mm is a lens of outstanding freedom from distortion and image quality owing to optimum speed and focal length. This leng with Compur interchangeable shutter has been specially developed tor the Hasselblad camera.

At full aperture and when stopped down moderately, the image quality of the Planar T* f/3.5-100 mm is superior to that of the 80 mm Planar lens. For this reason the lens is recommended as standard lens for photography where the demands for detail recognition and brilliance are high.

The excellent distortion correction is also of great importance for architectural photography and for all applications which require an exact reproduction of the geometry of the object (e. g. for surveying).

Manufacturer description #2

The 100mm f/3.5 Planar lens meets the highest demands for correction of distortion and resolution. This lens renders finest details right out to the edges of the 2 1/4 x 2 1/4 format, even at maximum aperture. Thanks to an ideal combination of focal length and lens speed, distortion has virtually been eliminated.

The 100mm Planar is a lens designed to uncompromising optical standards. It even surpasses the standard 80mm Planar in resolution if both lenses are used at full aperture or stopped down at f/4 or f/5.6. Its properties are shown to best advantage at long lens-to-object distances.

The 100mm Planar is recommended for all kinds of photography calling for exceptional resolving power and image brilliance, especially when big blow-ups of details are needed. Outstanding distortion correction makes the lens very suitable for photogrammetric purposes, aerial photography, architectural photography and other occasions when image geometry is especially important to interpretation by measurements. The lens can also be used to advantage for scientific and technical applications demanding extreme precision.

Residual aberrations in the 100mm Planar have been reduced to such a degree that the lens satisfies requirements for surveying optics.

From the Hasselblad House magazine (3/1971)

The 100 mm f/3.5 Planar lens for 2 1/4"-square SLR cameras, which was announced in the Fall of 1968, holds a unique position among the lenses designed in recent years. Demands imposed on lens design, such as space for shutters, camera space requirements etc., previously led to an increase in the number of lens elements as a rule. The intention with the 100 mm f/3.5 Planar was to develop a lens with an optimized speed-focal length ratio which would result in a standard focal length lens for which no special requirements had to be satisfied to make correction more difficult. Freed from many technical restrictions and using mathematical methods of optimization in conjunction with large computers, it was possible to create a Planar lens with extraordinary resolving power over the entire field right out to the corners, even when used wide open. A further result of this optimization was an outstanding lack of distortion so that just about perfect reproduction of subject geometry was guaranteed.

The Planar’s anti-reflection coating also eliminated one of the shortcomings displayed by older Gauss-type lenses, namely multiple reflections which produce double images, bright patches or, when double images are not apparent, degraded image brilliance.

With complete justification, the 100 mm f/3.5 Planar can be termed the product of a wise conception which made it possible to create a top-quality lens for the 2 1/4 x 2 1/4" format with only 5 elements in 4 groups. The 100 mm f/3.5 Planar is further proof of the fact that the number of lens elements in itself is no measure of quality.

However, mathematically accurate correction of a top quality lens is only one aspect of lens quality. This correction does not make greater tolerances possible, as many laymen believe. Quite the opposite! Only a lens made with the highest precision can display the finest resolving power. This also applies to the 100 mm f/3.5 Planar. Moreover, positioning of the camera’s film plane must be very exact and the lens must be focused with requisite accuracy. Except when used wide open, the 100 mm f/3.5 Planar, in combination with the automatic Compur leaf shutter, offers real advantages, since the lens is always focused wide open. When the shutter is tripped, the lens automatically stops down to the pre-selected f/stop and the increase in depth-of-field compensates for any slight focusing inaccuracy.

The arrival of the 100 mm f/3.5 Planar does not immediately dethrone every other top quality lens of about the same focal length and speed. The new lens is a complement to the previous series of Zeiss lenses for the Hasselblad. The diagonal angle of view is about 43°, only about 20% less than that of the standard 80 mm Planar, and the maximum effective aperture is a little more than half a stop less. The superior and extraordinarily even definition across the entire field is at its best in the center and at the outer edges of the a field. For this reason, the lens can be recommended for all pictures requiring extremely sharp rendition of details, whether they be in landscapes or of people or groups. The 100 mm f/3.5 Planar is also just right for architectural work in which maximum accuracy in the rendition of the smallest details is needed and space conditions do not call for the use of a wide-angle lens. Outstanding correction for distortion is also of the greatest importance in applications demanding extreme accuracy in the reproduction of subject geometry. Residual distortion in the 80 mm f/2.8 Planar is, of course, small enough to justify the designation "distortionless" for the lens for most professional and amateur requirements. But residual faults have been reduced to such an extent in the 100 mm f/3.5 Planar that the lens even satisfies the demands imposed on special-purpose photogrammetric lenses.

The outstanding resolving power of the 100 mm f/3.5 Planar, especially apparent in enlargements, is greatest when the lens is focused at long distances, for which optimum correction has been made. For close-up work the lens is really no better than the 80 mm f/2.8 Planar. Residual distortion in the 100 mm f/3.5 Planar also increases at close-up distances. But at the shortest focusing distance, 29 1/2" (0.9 m), the 100 mm f/3.5 Planar’s residual distortion is still less than that of the 80 mm f/2.8 Planar, which does not change much over its focusing range.

On the other hand, the 100 mm f/3.5 Planar is no competitor to the 120 mm f/5.6 or 135 mm f/5.6 S-Planar lenses, i.e. Planar-formula lenses with outstanding resolving power, irrespective of the focusing distance, but which have optimum correction in the close-up range. A further feature of the 100 mm f/3.5 Planar should also be mentioned. As you may know, lens illumination of the field declines from the center of the field to the edges. One of the reasons for this is because of "natural" light fall-off, which is obtained from the product of the diameter of the entry pupil for light rays entering at angle w and cosine 4w. The other reason is due to vignetting which often occurs when a lens is used wide open or nearly so. These two types of light fall-off are additive with the result that light loss at the maximum effective aperture first increases slowly as the angular field increases, i.e. the angle from the center of the field, and then increases more or less abruptly at the marginal zones of the field. Light fall-off is then obtrusive. However, this is not the case with the 100 mm f/3.5 Planar. Illumination of the field follows a carefully balanced course, even when the lens is used wide open.

Carl Zeiss C series

The first generation of Carl Zeiss lenses with a built-in leaf shutter, introduced in 1957.

  • Synchro-Compur leaf shutter with self-timer (V);
  • Fully synchronized for M- and X-settings so that you can work with flash at all shutter speeds;
  • Aperture and shutter speed are cross-coupled by default but can be set independently for complete creative control;
  • Originally matt-chromed, all C lenses were supplied in black trim from 1969 to 1981;
  • T* multi-coated from 1973 (30-80mm focal length range), 1974 (all focal lengths).

Frequently asked questions (1)

  • What does the Carl Zeiss lens designation "Planar" mean?

    The Planar is one of the most successful camera lens designs ever created. It provides the lens designer with the ideal basis for high-performance lenses with excellent anastigmatic flatness of the image field, outstanding correction of chromatic aberration, high speed and low distortion. The optical performance is remarkably constant over a wide range of imaging ratios, enabling such a versatile lens variety as the Makro-Planar lenses, optimized for close range photography. The Planar design is the basis for nearly all professional standard and medium focal length lenses and also for the fastest lenses ever created. In the Hasselblad range the fastest lens is consequently a Planar: the Planar FE 2/110 mm. / Source: Hasselblad literature /

Other standard prime lenses in the Hasselblad V system

Sorted by focal length and speed, in ascending order

Hasselblad V mount (8)
Carl Zeiss Planar [T*] 80mm F/2.8 CA7 - 50.90mB50 1957 
Carl Zeiss Planar T* 80mm F/2.8 FA7 - 50.60mB50 1977 
Carl Zeiss Planar T* 80mm F/2.8 CFA7 - 50.90mB60 1982 
Carl Zeiss Planar T* 80mm F/2.8 FEA7 - 50.60mB50 1991 
Carl Zeiss Planar T* 80mm F/2.8 CBA6 - 50.90mB60 1997 
Carl Zeiss Planar T* 80mm F/2.8 CFEA7 - 50.90mB60 1998 
Carl Zeiss Planar T* 100mm F/3.5 CFA5 - 40.90mB60 1982 
Carl Zeiss Planar T* 100mm F/3.5 CFiA5 - 40.90mB60 1998 
Subscribe
Notify of
guest

Copy this code

and paste it here *

0 comments
Inline Feedbacks
View all comments

Copyright © 2012-2024 Evgenii Artemov. All rights reserved. Translation and/or reproduction of website materials in any form, including the Internet, is prohibited without the express written permission of the website owner.

Chromatic aberration

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

Spherical aberration

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

Astigmatism

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

Coma

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

Curvature of field

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

Distortion

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

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

Diffraction

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

Doublet

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

Dynamic range

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

Resolving power

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

Vignetting

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

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

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

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

Flare

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

Ghosting

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

Retrofocus design

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

Anastigmat

A photographic lens completely corrected for the three main optical aberrations: spherical aberration, coma, and astigmatism.

By the mid-20th century, the vast majority of lenses were close to being anastigmatic, so most manufacturers stopped including this characteristic in lens names and/or descriptions and focused on advertising other features (anti-reflection coating, for example).

Rectilinear design

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

Focus shift

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

Transmittance

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

Modulation Transfer Function (MTF)

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

The components of MTF are:

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

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

Veiling glare

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

Anti-reflection coating

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

Benefits of anti-reflection coating:

Circular fisheye

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

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

Diagonal (full-frame) fisheye

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

Extension ring

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

View camera

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

135 cartridge-loaded film

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

120 roll film

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

120 roll film

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

120 roll film

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

220 roll film

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

220 roll film

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

220 roll film

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

Shutter speed ring with "F" setting

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

Catch for disengaging cross-coupling

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

Cross-coupling button

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

M & X sync

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

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

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

X sync

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

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

1 - 1/500 + B

1 second - the slowest available shutter speed.

1/500th of a second - the fastest available shutter speed.

B (Bulb) - a setting in which the shutter stays open as long as the release button remains depressed.

MF

Sorry, no additional information is available.

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, Leica, Nikon, Pentax, Sony etc.) are always incompatible. In addition to the mechanical and electrical interface variations, the flange focal distance (distance from the mechanical rear end surface of the lens mount to the focal plane) is also different.

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 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/3.5 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 lens element 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.