Canon 7

35mm MF film rangefinder camera

Specification

Production details:
Announced:September 1961
System: Canon S (LSM) (1949)
Format:
Maximum format:35mm full frame
Film type:135 cartridge-loaded film
Mount and Flange focal distance:Leica screw mount [28.8mm]
Shutter:
Type:Focal-plane
Model:Mechanical
Speeds:1 - 1/1000 + B, T
Exposure:
Exposure metering:Through the separate window
Exposure modes:Manual
Physical characteristics:
Weight:670g
Dimensions:140x81x31mm

Manufacturer description #1

Lens: Model 7 accepts Canon's unique bayonet-mount Canon lens 50mm F0.95, as well as all thread-mount Canon lenses from 25mm to 1000mm.

Shutter: All metal focal plane shutter. Single-pivot, rigid shutter speed dial equally calibrated from 1/ 1000th to 1 sec., B & T plus self-timer.

Exposure Meter: Built-in light meter coupled to shutter speed dial. Sensitivity range is from LV6 to LV19.

Finder: Universal viewfinder for 35, 50, 85, 100, and 135mm Canon lenses. Parallax error corrected automatically when focused.

Lens Mount: New dual mount takes all thread-mount Canon lenses as well as the new bayonet mount 50mm F0.95.

Focusing: Double-image superimposing system.

Film Wind: Single-stroke winding lever.

Exposure Counter: Self-resetting-type.

Film Rewind: Rapid crank system.

Film: Any 35mm film cassette.

Film Speed Indicator: ASA 6 to 400 (DIN 9 to 27) on the shutter speed dial.

Flash Synchronization: FP and MX synchronization. Continental-type flash socket.

Manufacturer description #2

The successor to the VI-series, this Canon camera was the first to have an Arabic numeral designation. Around 1961, the market for top-quality 35mm cameras was quickly shifting to SLR cameras. Although Canon had already marketed the Canonflex, it concluded that rangefinder cameras for quick shooting was still in strong demand. The 7 had a built-in exposure meter which cameras up to the VI did not have. The viewfinder featured projected frames matching lenses from 35mm to 135mm. The ultra-fast 50mm f/0.95 dream lens was also developed at the same time for the camera. Both the Canonet and the 7 were announced at the 7th Photokina.

From the Classic Camera magazine (February 1999)

Canon made its mark in the international photographic markets with its Leica format screw mount rangefinder cameras, and the Canon 7 represents the peak of this format's evolution both referred to the viewfinder system and the structure in general. Introduced in 1961, the Canon 7 was made in 135.000 examples up until 1964, when it was replaced by the 7S equipped with a CdS cell and very rare today as it was made in just 20.000 examples up until 1968.

It is a screw mount camera with an external bayonet mount, multi-focal, luminous frame viewfinder, selenium light meter and a steel blade shutter offering excellent performance even by today's standards.

The layout is typical of a rangefinder camera, with the controls to the right, following a trend that was also carried over in 35mm SLRs.

On the whole, the camera's lines are quite heavy, but charming nonetheless. From a practical point of view, on the other hand, the Canon 7 is easy to use and very stable.

The Canon 7 in detail

The film wind lever, frame counter, shutter speed selector, shutter release, light meter window, the viewfinder frame selector and film rewind lever crank, are all on the top plate. The double action film wind lever describes an arc of 170° and can be used in a single sweep or in additional movements. In its operative position it is offset from the camera body and appears aesthetically quite gawky, though very functional. An oversized knob, placed coaxially to the threaded shutter release is used as the shutter lock, plus with remote cables, and as the film release for rewind purposes, or finally, to cock the shutter for multiple exposures. These are facilitated by the easy to see frame counter which can easily be checked for unwanted movement of the film, which has to be kept in tension by means of the rewind lever.

A small button to release the film speed selector, which is quite difficult to operate, plus a switch for the two light metering scales and the viewfinder eyepiece are at the back of the camera. The camera back release key is placed at the left of the base plate under the standard synch socket for use in flash mode. The socket has a bayonet which engages with a Canon dedicated flashgun or an accessory bracket for standard flashguns or additional viewfinders. The key also doubles as a shaft to control the special Canon film cassettes which achieved light tightness without the usual velvet strips by means of complex counter rotating bushes. At the right of the base plate is a 1/4 inch screw thread for tripod mounting. This solution - strongly offset from the optical axis - is unjustified considering that the camera back opens on the side, but must have been maintained through force of habit.

The viewfinder and light meter

The luminous frame viewfinder with automatic parallax correction is excellent and can be switched to four positions, respectively covering 35mm, 85mm, 100mm and 135mm focal lengths via the control placed over the eyepiece. The rangefinder is at the centre of the frame; it is very accurate, but contrast is low and therefore is difficult to use.

The light meter makes use of a large selenium cell placed at the front of the camera, around the second rangefinder window; it is couple to the shutter speed but is not noted for ease of use and accuracy. On the other hand, an average light meter is better than no meter at all. The film speed scale - in DIN and ASA - is barely adequate, as it covers a range between 6 and 400 ASA. The EV range is also disappointing, ranging from 6 to 19 EV for a 100 ISO film. On the other hand, the high quality components - cell included - ensure that the device is very durable and is still perfectly functional in most Canon 7's even today. Its use is similar to that of any hand held device (its angle of view is similar to that of a standard lens): all the operator has to do is point it to the subject, read the aperture and transfer the setting to the lens.

The shutter

The shutter is an 18 micron steel curtain with a range of speeds between 1/1000s and 1s, plus B, T and X setting, specifically introduced for electronic flashguns as maximum synch speed. As was the norm for cameras of this period, synch is also calibrated on all speeds for flashbulbs (in particular, the FP and M models synch at all speeds except 1/30s, X and B; M models synch between 1/125s and Is except 1/125 and X; F models synch between 1/30s and Is, plus B setting). Releasing the shutter on T pose leaves the device open until the speed selector knob is moved.

At the front of the camera, bottom right is the mechanically operated self timer lever which has a delay of 10 seconds and is activated by the shutter release.

Lens mount and lenses

The lens is a six element 50mm f/1.4, but the camera could also be equipped with f/1.8, f/1.2 - and an impressive f/0.95 - standard lenses. The mount is the classic Leica format screw thread, modified by the addition of an external bayonet used to avoid vignetting when using the ultra fast f/0.95 standard lens or the Reflex Mirror Box 2 accessory. These days, finding an adequate range of all types of lens is quite easy. Staying in the Canon camp, the range of contemporary lenses for the Canon 7 extended to a 25mm wide-angle and a 1000mm super telephoto and most of these are easy to find.

On the accessory side, there is a range of additional lenses with viewfinder correction, and the already mentioned reflex box, while a little rarer are accessories such as a tripod mounting bracket, an additional accessory bracket, the repro accessory for copying and microscope photography.

Even today, it is easy to repair a Canon 7, with the exception of the light meter, for which parts are no longer made.

Similar cameras (21)

35mm full frame • Manual focus • Film • Rangefinder • Leica screw mount mount

Model Shutter Metering Modes Year
Cosina Voigtlander BESSA-R M, 1/2000 TTL • WA M 2000
Leica II (Model D) M, 1/500 -- M 1932
Leica IIc M, 1/500 -- M 1948
Leica IIf M, 1/500 -- M 1951
Leica III (Model F) M, 1/500 -- M 1933
Leica IIIa (Model G) M, 1/1000 -- M 1935
Leica IIIb (Model G) M, 1/1000 -- M 1938
Leica IIIc M, 1/1000 -- M 1940
Leica IIId M, 1/1000 -- M 1939
Leica IIIf M, 1/1000 -- M 1950
Leica IIIg M, 1/1000 -- M 1957
Minolta-35 Model A M, 1/500 -- M 1947
Minolta-35 Model B M, 1/500 -- M 1947
Minolta-35 Model C M, 1/500 -- M 1948
Minolta-35 Model D M, 1/500 -- M 1949
Minolta-35 Model E M, 1/500 -- M 1951
Minolta-35 Model F M, 1/500 -- M 1952
Minolta-35 Model II M, 1/500 -- M 1953
Minolta-35 Model IIB M, 1/500 -- M 1958
Yashica YE M, 1/500 -- M 1959
Yashica YF M, 1/1000 -- M 1959
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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.

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.

Manual diaphragm

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

Preset diaphragm

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

Semi-automatic diaphragm

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

Automatic diaphragm

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

Fixed diaphragm

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

Number of blades

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

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

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

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.