Canon FDn 7.5mm F/5.6 Fisheye

Fisheye lens • Film era • Discontinued


FD The lens is designed for Canon 35mm film SLR cameras with the Canon FD mount.
n (Unofficial acronym) A new generation of FD series lenses without the breech-lock ring.
FISHEYE An ultra-wide angle lens with strong uncorrected barrel distortion and extreme angle of view.

Model history (3)

Canon FD 7.5mm F/5.6 FisheyeM11 - 80.30m-- 1971 
Canon FD 7.5mm F/5.6 S.S.C. FisheyeM11 - 80.30m-- 1973 
Canon FDn 7.5mm F/5.6 FisheyeM11 - 80.35m-- 1979 

Features highlight

Extreme AoV
Circular fisheye
Fixed focus
Built-in filters


Production details:
Announced:June 1979
Production status: Discontinued
Original name:CANON FISH-EYE LENS FD 7.5mm 1:5.6
System:Canon FD (1971)
Optical design:
Focal length:7.5mm
Maximum format:35mm full frame
Mount and Flange focal distance:Canon FD [42mm]
Diagonal angle of view:180°
Lens construction:11 elements in 8 groups
Fixed focus
Circular fisheye
Diaphragm mechanism:
Diaphragm type:Manual
Aperture control:Aperture ring
Number of blades:6 (six)
Closest focusing distance:0.35m
Magnification ratio:<No data>
Manual focus control:None
Physical characteristics:
Maximum diameter x Length:⌀72×62mm
Filters:Removable front filters are not accepted
Built-in SKY, Y3, O1, R1, CCA4, CCB4 (part of the lens optical system)
Lens hood:Not available
Teleconverters:Canon Extender FD 2X-B → 15mm F/11.2
Sources of data:
1. Canon FD interchangeable lenses booklet (PUB. IE01-075) (May 1979).
2. Lens Wonderland. Canon FD lens guide book (PUB. C-IE-097AZ) (May 1987).
3. Specifications of Canon New FD lenses (PUB. C-II-099B) (July 1981).
4. Canon FD interchangeable lenses booklet (PUB. C-IE-075AF) (May 1981).
5. Lens Work. The Canon guide to interchangeable lenses and Single Lens Reflex photography.
6. Quick reference guide.
7. Canon AE-1 Program booklet (PUB. C-CE-124) (December 1980).
8. Canon AL-1 Quick focus booklet (PUB. C-CE-135A) (January 1982).
9. The New F-1 World booklet.
10. Canon A-1 booklet (PUB. C-CE-0990) (September 1980).
11. Canon AE-1 booklet (PUB. C-CE-1056AB) (September 1980).
12. Canon FD lenses sales guide.
13. Canon Reflex 1981/1982 booklet.
14. Canon interchangeable lenses FD booklet (PUB. C-IE-075AQ) (March 1982).
15. Canon Reflex booklet (1985).
16. Canon FD lenses instructions (PUB. II01-061I) (July 1979).
17. Canon FD interchangeable lenses booklet (PUB. C-IE-075AL) (December 1981).
18. Canon AE-1 booklet (PUB. C-CE-1056Y) (February 1980).
19. Canon Products Guide (PUB. C-CE-114BI) (February 1983).
20. Canon Products Guide (PUB. CE01-114B) (July 1979).

Manufacturer description #1

A circular fish-eye which covers its 180-degree angle of view in a 23mm circle within the 35mm frame. Despite its very short focal length, its retrofocus design means that the camera mirror, instead of having to be locked up before mounting, remains conveniently in position for viewing. With limitless depth of field, it promises sharp reproduction at any shooting distance or aperture, and, consequently, neither needs nor has a focusing mount. Equidistant projection over its entire angle of view makes it very appropriate for certain types of scientific photography; for the less scientifically-inclined, an exciting special effects lens. With manual diaphragm and six built-in filters (SKY, Y3, O1, R1, CCA4, CCB4).

Manufacturer description #2

Conceived for astronomical and meteorological uses, this lens has a 180 degrees angle of view in a 23mm diameter circle. All lines with the exception of those passing through the lens' horizontal and vertical center follow the natural curve of the circular image.

Its retrofocus design eliminates the need to lock the camera's mirror up. This permits uninterrupted viewing and is especially valuable given the unusual perspective inherent in this lens. Focusing is unnecessary due to its tremendous depth of field consequently a focusing mechanism is not incorporated. With a close minimum focusing distance of 35cm and correction of aberrations, particularly astigmatism and coma, sharp results are attained at any aperture and virtually any shooting distance.

Using a rotating turret, the Fisheye 7.5mm lens features six built-in filters, Sky, Y3, O1, R1, CCA4 and CCB4. Its extremely wide angle of view does not permit the use of a lens hood. Manually-operated diaphragm with stopped-down metering.

Manufacturer description #3

Looking through the viewfinder of a camera equipped with a 7.5mm fisheye lens is startling. You see everything from the ground at your feet (and perhaps your feet, too), to the sky overhead and virtually everything to your right and left within a radius of 180 degrees. The image in the viewfinder is circular and that's the way it will be reproduced on film. The fisheye lens' view is like that of a fish looking through the water to the surface. Because of the refraction between water and air the fish has a tremendously wide angle of view. The front element of a fisheye lens has an extreme amount of curvature which accounts for its 180 degrees vision. The large, concave lens in front covers the subject area and then bends the light into approximately a 90 degrees cone. The convex lens at the rear then forms the image on film. The same degree of coverage in a conventionally designed lens would require a much larger image area. Instead, with this lens, a limited circular image is projected on film. Due to the small image area, straight lines are rendered in a barrel or arch shape. Using the equidistant projection method, this circular image fisheye with its 7.5mm focal length compresses the 180 degrees field into a 23mm diameter circle.

Originally designed for scientific studies, the 7.5mm fisheye was once called the full sky lens. It was primarily used for astrophotography and astronomical observations. Today, however, the fisheye is widely used by professional photographers when special effects are desired.

Imaginative use of the fisheye can create a world of mystery from the most conventional subject matter.

The fisheye lens bends straight lines, whether vertical or horizontal. However, lines at the center of the image show little or no distortion. If you want to emphasize the special effects of the fisheye using familiar subjects, choose a scene with a predominance of straight lines - particularly away from the center of the subject area. Curved or rounded objects may exhibit some fisheye effect in the photograph, but often not to a marked degree.

While there is no focusing mechanism on the 7.5mm fisheye, it can be used effectively for close focusing. The extremely short 7.5mm focal length and f/5.6 aperture combine to provide tremendous depth of field.

With a fisheye you must keep in mind that you're shooting with a lens that covers a field of view of 180 degrees. Check the finder for the intrusion of unwanted objects such as your feet, tripod legs or even part of the camera strap. its extremely wide angle of view doesn't permit the use of a lens hood hence it cannot be protected from the direct rays of the sun or bright backlight. However, the sun can often be included effectively in the photograph.

Manufacturer description #4

This new lens is one of the most compact circular-image fish eye lenses available today...

It is particularly sharp and well corrected for color aberrations, in addition to having excellent performance at any distance.

Focusing is unnecessary because of the inherently great depth-of-field of this focal length. Since it is of retrofocus design, it does not require mirror lock-up. It is an ideal lens for the photographer seeking dramatic effects as well as the scientist or technical photographer needing a hemispherical lens for special observations.

Typical characteristics of fisheye lenses

  • Extreme angle of view (at least 180° diagonally);
  • Circular types (the image circle of the lens is inscribed in the image frame) or diagonal types (cover the entire image frame);
  • Usually of equidistant projection type, with the distance from the picture center to any given point always proportional to the angle from the optical axis to that point;
  • Huge barrel distortion;
  • Short closest focusing distance (0.20 - 0.30m with 35mm full-frame prime lenses);
  • Very large depth of field, eliminating the need for autofocus or precise manual focusing;
  • Due to the extreme angle of view and convex front element, front filters cannot be used;
  • Often equipped with a filter turret with swivel-mounted filters;
  • Often come with a small, built-in petal-shaped lens hood.

Other fisheye lenses in the Canon FD system

Sorted by focal length and speed, in ascending order

Canon FD mount (4)
Canon FD 7.5mm F/5.6 FisheyeM11 - 80.30m-- 1971 
Canon FD 7.5mm F/5.6 S.S.C. FisheyeM11 - 80.30m-- 1973 
Canon FD 15mm F/2.8 S.S.C. FisheyeA10 - 90.30m-- 1973 
Canon FDn 15mm F/2.8 FisheyeA10 - 90.20m-- 1980 

Lenses with similar focal length

Sorted by manufacturer name

Canon FD mount (3)
Sigma MF 8mm F/4 FisheyeA10 - 60.20m-- 1988 
Sigma MF 8mm F/4 Fisheye ZENA10 - 60.20m-- 1992 
Sigma MF 8mm F/4 Filtermatic FisheyeA11 - 70.20m-- 1982 
Interchangeable mount (2)
BelOMO Peleng A 8mm F/3.5 Fisheye MC [T]P? - ?0.22m--
Spiratone 7mm F/5.6 Fisheye [T]
aka Hanimex 7mm F/5.6 Fish-eye
P? - ?--
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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.


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.


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.


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You are already on the page dedicated to this lens.

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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".

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/5.6 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.