Large, Fully Electronic Mount System

Description of Lens Designation

The lens designations follow a standard format to identify the lens.

Canon EF Lens Accessories

Focus Preset

With the focus preset feature, you can set the desired focusing distance in memory and later instantly focus the lens at that distance. Normal picture-taking and focusing are possible even while focus preset has been set. At a soccer game, for example, you can preset the focus for the goal. You can focus normally while the player approaches the goal, then when the ball is shot into the goal, you can obtain instant focus.

The conventional interface between the lens and camera body was mechanical, with the use of engaging levers and gears. This method caused physical problems such as wear and rattle. It was limited and more diverse information could not be exchanged. Canon EF lenses do not use such mechanical links at all. About 50 items of information are exchanged as digital signals between the lens and camera in real time. This enables high- speed and high-precision control. And since the lens mount diameter is an ample 54 mm, special lenses such as

EF 75-300mm f/4-5.6 IS USM

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Focal length:

Maximum aperture:

 

Special Function:

USM:

Indicates

Indicates the focal

Indicates the lens’

 

Any special

that the lens uses

length range from

maximum aperture.

 

feature such as an

an Ultrasonic

the shortest to

(See below for

 

image stabilizer,

Motor for

longest length.

details.)

 

macro feature, etc.,

autofocusing.

(See below for

 

 

 

 

 

 

 

 

is indicated.

(See page 34 for

details.)

 

 

 

 

 

 

 

 

 

 

 

 

details.)

General Purpose Filters for Black and White or Color Film

Sky (1A), Haze (UV-1), ND (03 • 0.6)

• 52mm • 58mm • 72mm

Conversion Filters for Color Film

80A, 80B, 85, 85B, FCB, FCD

• 52mm • 58mm • 72mm

General Purpose Filters for Black and White Film

Yellow 2, Green 11, Orange 15, Red 25A

• 52mm • 58mm • 72mm

Drop-in Filters

Drop-in Filters PL-C

Drop-in Filters PL-C can be rotated from the outside without removing them from the lens for precise control. The 48mm PL-C filter can be used with the following lens- es – EF 200mm f/1.8L USM and EF 1200mm f/5.6L USM; the 52mm PL-C filter is designed for use with the EF 300mm f/2.8L IS USM, EF400mm f/2.8L IS USM, EF 500mm f/4L IS USM and EF 600mm f/4L IS USM.

large-aperture lenses and TS-E lenses

Softmat Filters

Fluorite (CaF2) and UD-Glass

The refraction of light differs depending on the wavelength. The point of focus therefore differs depending on the different wavelengths or colors. When the different wavelengths are focused at different points, the colors look smeared. This is called chromatic aberration. The longer the focal length, the more pronounced chromatic aberration becomes. Usually, an achromatic

can be used. The EF mount is an advanced interfacing system with infinite possibilities.

Built-In Motor and EMD

Canon EF lenses (except TS-E and MP-E lenses) have a built-in AF motor. Compared to camera body-based AF motors, lens-based motors have driving energy with lower transmission loss. The optimum AF motor for the particular lens can also be selected and installed.

Focal Length

A focal length of 50mm is closest to what the eye sees. This focal length is used as a reference point for lens categories. For example, lenses with a shorter focal length are called wide-angle lenses, while those with a longer focal length are called telephoto lenses. Single focal length lenses have only one focal length, while zoom lenses have a range of focal lengths. (When EF lenses are used with the EOS IX, the focal

two, one for each end of the focal length range. For example, a EF 28-80mm f/3.5-5.6 lens has a maximum aperture of f/3.5 at 28mm and f/5.6 at 80mm.

Aperture and Shutter Speed

Under the same light level, if the aperture opening is made larger by one step, the shutter speed can be increased by one step. For example, if an aperture of f/5.6 and shutter speed of 1/60 sec. are set, adjusting the aperture to f/4 will

Softmat filters mildly soften the focus for flattering portraits and dreamy landscapes. These filters utilize the effect of diffraction which occurs between light passing through the transparent part and light passing through the coated part. Use Softmat No. 1 filter for a gentle softfocus effect, and Softmat No. 2 for a stronger effect.

No.1, No.2

• 52mm • 58mm

Warming Filters for Color Film

81A, 81B

• 52mm • 58mm • 72mm

Drop-in Gelatin Filter Holders

These glass-backed holders accept up to three commercially available cut- to-size gelatin filters for rear-insertion lenses. A 48mm holder is provided standard with EF 200mm f/1.8L USM and EF 1200mm f/5.6L USM; and a 52mm holder, with EF 300mm f/2.8L IS USM, EF 400mm f/2.8L IS USM, EF 500mm f/4L IS USM and EF 600mm f/4L IS USM.

element is used in a lens to correct chromatic aberration. However, normal optical glass can only be corrected for two primary spectral colors. An exception to this limitation is Fluorite, an ideal material. Fluorite, which is crystalline, has abnormally low refraction and low dispersion characteristics, which optical glass cannot achieve. It also has anomalous dispersion from the green to blue wavelengths. Canon developed production technologies to manufacture Fluorite. By incorporating Fluorite in lenses, the points of focus of the three primary spectral colors of red, green, and blue all meet at one point for ideal correction of chromatic aberration. There is also UD-glass, which is a special type of optical glass whose properties nearly match those of Fluorite. The effect of two UD-glass elements is equivalent to having one Fluorite element. And one super UD-glass element gives almost the same effect as one Fluorite element.

Comparison of optical characteristics between optical glass and Fluorite

Red

GlassBlue

Anomalous dispersion

Red

Blue

Fluorite

Fluorite and UD glass

The AF operation is therefore quick, quiet, and highly precise. The lenses also have an EMD (Electromagnetic Diaphragm) to control the aperture electronically. The aperture can be set either with an electronic dial or with the electronic pulse signal sent according to the exposure reading. Aperture control precision is therefore unmatched.

Ring-type USM

EMD

Built-in motor and EMD

Inner Focusing and

Rear Focusing

An inner focusing lens has the focusing lens group(s) in front of the diaphragm, while a rear focusing lens has the focus- ing lens group(s) behind the diaphragm. Both focusing systems allow the focusing lens group to be small. This minimizes the load on the actuator which drives the autofocus. In turn, the AF speed is faster. The whole optical system can also be made more compact. Also, since the lens does not rotate during focusing, the effects of a circular polarizing filter or gelatin filter remain intact.

length corresponds to 1.25 times that indicated for 35mm cameras.)

Angle of View

This indicates how much coverage of the scene you can see through the lens. Telephoto lenses have a narrower angle of view than wide-angle lenses.

Angle of View and Perspective

Perspective refers to the distance between the near and far objects that you can see at the same time. When the angle of view is wide (with a shorter focal length), the perspective becomes more apparent. And with a narrow angle of view (with a longer focal length), the perspective becomes less apparent. The image also becomes more compressed, with the far objects looking like they are right behind the nearer objects.

Maximum Aperture

This indicates the speed of the lens. A fast lens has a large maximum aperture, allowing more light to enter. The smaller the maximum aperture’s f-number, the larger the aperture opening is. A larger maximum aperture makes the image look brighter and easier to see through the viewfinder. You can also use a faster shutter speed or obtain better background blur. On the other hand, a smaller maximum aperture (the f-number is larger) allows the lens to be more compact and light. Single focal length lenses have only one maximum aperture while zoom lenses may have

enable a shutter speed of 1/125 sec. to be used. An aperture of f/2.8 will allow a faster shutter speed of 1/250 sec. while the same exposure level is maintained.

Depth of Field

Normally, there is only one point of optimum focus. However, we often see objects in front of or behind this point also in focus. This is made possible by a wide depth of field.

Depth of Field with the Aperture and Focal Length

The depth of field is mainly determined by the lens focal length, aperture, and subject distance. For example, if a wide- angle lens is used at the minimum aperture, almost everything in the picture will be in focus. However, if a telephoto lens is used at maximum aperture, the background will be really blurred, making the subject in focus stand out.

Circular Polarizing Filters PL-C

Polarizing filter enhances picture quality by blocking harmful reflected light. Use it to reduce polarized light reflections from glass and water surfaces or to improve color satura- tion. Simple to use, circular polarizing filters (such as Canon’s PL-C) polarize light circularly, rather than linearly, so it does not interfere with autofocus or TTL light metering.

52mm • 58mm • 67mm • 72mm • 77mm (Type II)

Loupe 8x & 4x

The Canon Loupe 4x is a high-performance magnifier for viewing the entire picture area (24 x 36mm) of a 35mm-format slide or nega- tive. With three lens elements in three groups, chromatic aberration and distortion are effec- tively corrected to give crystal-clear images. Eye fatigue is not a problem even after pro- longed use. Loupe 8x is another magnifier for viewing the entire picture area, but with spe- cial emphasis on a 24mm-diameter area at the center. The four lens elements in four groups attain high performance and a high magnifica- tion. All elements have Super Spectra Coating to make image viewing clear enough for you to effectively check the quality of photos taken with EF lenses. These two loupes can make your evaluation of photos more accurate.

Drop-in Screw Filter

Holders With Protect

Filters

The enclosed regular filter can be exchanged with other commercially available screw- type filters. Note that only filters with correct filter frame thickness can be mounted on the lens.

• 48mm • 52mm

Only Canon filters are guaranteed for use with EF lenses.

Gelatin filter Holders III & IV

Gelatin Filter

Gelatin Filter

Holder III

Holder IV

Gelatin Filter Holder III uses 3 x 3-inch gelatin filters and Gelatin Filter Holder IV uses 4 x 4- inch gelatin filters. Holders III and IV both provide extension hoods and ø52 mm, 58 mm, 67 mm, 72 mm and 77 mm adapters. Refer to the EF Lens Accessory Table for information on lens combinations.

52mm • 58mm • 67mm • 72mm • 77mm

Adapter III for EF 50mm 1: 1.4

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Canon EF Lenses manual Canon EF Lens Accessories