|■Leitz Wetzlar SUMMARON 35mm F/2.8||M||6 - 4||0.7m||E39||1958 ●|
|■Leitz Wetzlar SUMMARON 35mm F/2.8 [LSM]||M||6 - 4||1m||E39||1958 ●|
|■Leitz Wetzlar SUMMARON 35mm F/2.8 with OVU||M||6 - 4||0.65m||E39||1958 ●|
■ Production details
|Production status:||● Discontinued|
|Order No.:||SIMOM / 11306 - silver|
|Original name:||LEITZ WETZLAR SUMMARON 1:2.8/35|
|System:||Leica M (1954)|
■ Optical design
|Maximum format:||35mm full frame|
|Mount and Flange focal distance:||Leica M [27.8mm]|
|Diagonal angle of view:||63.4°|
|Lens construction:||6 elements in 4 groups|
■ On Leica M8/M8.2 APS-H [1.33x] cameras
|35mm equivalent focal length:||46.6mm (in terms of field of view)|
|35mm equivalent speed:||F/3.7 (in terms of depth of field)|
|Diagonal angle of view:||49.8°|
|Coupled to the rangefinder:||Yes|
|Closest focusing distance:||0.7m|
|Maximum magnification:||<No data>|
|Focusing modes:||Manual focus only|
|Manual focus control:||Focusing tab|
■ Diaphragm mechanism
|Aperture control:||Aperture ring|
|Number of blades:||10 (ten)|
■ Physical characteristics
|Maximum diameter x Length:||⌀51×29mm|
|Lens hood:||ITDOO / 12570|
|IROOA / 12571|
|Lens caps:||14031 (front)|
■ Sources of data
|1. Leica lenses booklet (PUB. 11-34d) (January 1963).|
|2. Interchangeable lenses are giving your LEICA new perspective booklet (PUB. 11-34) (April 1960).|
|3. Leica lenses booklet (PUB. 11-34b) (October 1961).|
From the LEICA photography magazine (1958, No. 4):
The 35mm Summaron f/3.5 wide-angle lens has always been in demand because of its brilliance, depth of field and overall sharpness at full aperture. It is a professional standby for covering fast-breaking picture stories, for "candid" photography where zone-focusing is most convenient and for pictures calling for foreground emphasis.
Now a new model Summaron, with all the advantages of the original, offers a top-speed of f/2.8 - some 50 per cent greater than the f/3.5 speed of the earlier lens. The f/2.8 model is a six-element symmetrical derivative, and takes advantage of new highly refractive lanthanum glasses in its design. By increasing the diameter of the front lens elements beyond the size called for by the f/2.8 aperture, designers have virtually eliminated vignetting. Performance at full aperture is excellent; optimum aperture is f/5.6.
Like the other new Leitz lenses, it has a linear diaphragm scale and click-stops. The f/2.8 Summaron, not scheduled for delivery until early 1959, will be available in screw-mount as well as in bayonet-mounts for the M 2 and M 3. The latter will include an Optical Viewing Unit.
The f/3.5 model of the 35mm Summaron continues to be available for both screw- and bayonet-mounting Leicas. A model in a mount for use on the Leica M 2 was announced at Photokina. It requires no Optical Viewing Unit, since the 35mm field is outlined by the M 2's finder. Price is $82.50, including tax.
Sometimes called "the Leica's basic wideangle", this was the popular choice for black-and-white and color photography whenever ultra-high-speed lenses weren't required.
Note: All bayonet-mount LEITZ wideangle lenses are available with integral optical viewing unit for the M3 and without this unit for the M2, which has a built-in 35 mm finder.
This Gauss type of short length has 6 elements and 4 members. The slight falloff towards the picture corners at full aperture disappears when the lens is stopped down. Optimum image quality is obtained between f/5.6 and 8.
According to the "Handbook of the LEICA system" (May 1987), the SUMMARON-M 2.8/35 has internal thread M39 x 0.5 and uses E39 filters.
Fast full-frame wide-angle prime lens
Genres or subjects of photography (7):
Landscapes • Cityscapes • Buildings • Interiors • Full to mid-body portraits • Street • Travel photography
Recommended slowest shutter speed when shooting static subjects handheld:
1/40th of a second
Sorted by focal length and speed, in ascending order
|Leica SUMMILUX-M 24mm F/1.4 ASPH.||M||10 - 8||0.7m||S.VII||2008 ●|
|Leica SUMMARON-M 28mm F/5.6 • Pancake lens||M||6 - 4||1m||E34||2016 ●|
|Leica ELMARIT-M 28mm F/2.8 ASPH. [II]||M||8 - 6||0.7m||E39||2016 ●|
|Leica SUMMICRON-M 28mm F/2 ASPH. [II]||M||9 - 6||0.7m||E46||2016 ●|
|Leica SUMMILUX-M 28mm F/1.4 ASPH.||M||10 - 7||0.7m||E49||2015 ●|
|Leica SUMMARIT-M 35mm F/2.4 ASPH. [II]||M||6 - 4||0.8m||E46||2014 ●|
|Leica SUMMICRON-M 35mm F/2 ASPH. [II]||M||7 - 5||0.7m||E39||2016 ●|
|Leica APO-SUMMICRON-M 35mm F/2 ASPH.||M||10 - 5||0.3m||E39||2021 ●|
|Leica SUMMILUX-M 35mm F/1.4 ASPH. [III]||M||9 - 5||0.7m||E46||2010 ●|
|Leica SUMMILUX-M 35mm F/1.4 ASPH. [IV]||M||9 - 5||0.4m||E46||2022 ●|
|Leica SUMMILUX-M 35mm F/1.4 [I]||M||7 - 5||1m||E46||2022 ●|
|Leica ELMAR-M 24mm F/3.8 ASPH.||M||8 - 6||0.7m||E46||2008 ●|
|Leica ELMARIT-M 24mm F/2.8 ASPH.||M||7 - 5||0.7m||E55||1996 ●|
|Leitz Wetzlar / Leitz Canada ELMARIT 28mm F/2.8 [I]||M||9 - 6||0.7m||E48||1965 ●|
|Leitz Wetzlar / Leitz Canada ELMARIT 28mm F/2.8 [II]||M||8 - 6||0.7m||E48||1969 ●|
|Leitz / Leitz Canada / Leica ELMARIT-M 28mm F/2.8 [III]||M||8 - 6||0.7m||E49||1979 ●|
|Leica ELMARIT-M 28mm F/2.8 [IV]||M||8 - 7||0.7m||E46||1993 ●|
|Leica ELMARIT-M 28mm F/2.8 ASPH. [I]||M||8 - 6||0.7m||E39||2006 ●|
|Leica SUMMICRON-M 28mm F/2 ASPH. [I]||M||9 - 6||0.7m||E46||2000 ●|
|Leitz Wetzlar SUMMARON 35mm F/3.5||M||6 - 4||1m||E39||1954 ●|
|Leitz Wetzlar SUMMARON 35mm F/3.5 with OVU||M||6 - 4||0.65m||E39||1956 ●|
|Leitz Wetzlar SUMMARON 35mm F/2.8 with OVU||M||6 - 4||0.65m||E39||1958 ●|
|Leica SUMMARIT-M 35mm F/2.5 [I]||M||6 - 4||0.8m||E39||2007 ●|
|Leitz Wetzlar / Leitz Canada SUMMICRON 35mm F/2 [I]||M||8 - 6||0.7m||E39||1958 ●|
|Leitz Wetzlar / Leitz Canada SUMMICRON 35mm F/2 [I] with OVU||M||8 - 6||0.65m||E39||1958 ●|
|Leitz Wetzlar / Leitz Canada SUMMICRON 35mm F/2 [II]||M||6 - 4||0.7m||E39||1969 ●|
|Leitz Wetzlar / Leitz Canada SUMMICRON 35mm F/2 [III]||M||6 - 4||0.7m||E39||1973 ●|
|Leitz / Leica SUMMICRON-M 35mm F/2 [IV] • Pancake lens||M||7 - 5||0.7m||E39||1980 ●|
|Leica SUMMICRON-M 35mm F/2 ASPH. [I]||M||7 - 5||0.7m||E39||1997 ●|
|Leitz Canada SUMMILUX 35mm F/1.4 [I]||M||7 - 5||1m||E41||1960 ●|
|Leitz Canada SUMMILUX 35mm F/1.4 [I] with OVU||M||7 - 5||0.65m||E41||1960 ●|
|Leitz Wetzlar / Leitz Canada SUMMILUX[-M] 35mm F/1.4 [II]||M||7 - 5||1m||S.VII||1967 ●|
|Leica SUMMILUX-M 35mm F/1.4 ASPHERICAL||M||9 - 5||0.7m||E46||1990 ●|
|Leica SUMMILUX-M 35mm F/1.4 [II] Titanium||M||7 - 5||1m||S.VII||1992 ●|
|Leica SUMMILUX-M 35mm F/1.4 ASPH. [II]||M||9 - 5||0.7m||E46||1994 ●|
Sorted by manufacturer name
|Cosina Voigtlander NOKTON 35mm F/1.2 Aspherical II VM||M||10 - 7||0.5m||⌀52||2011 ●|
|Cosina Voigtlander Color-SKOPAR 35mm F/2.5 P II VM • Pancake lens||M||7 - 5||0.7m||⌀39||2004 ●|
|Cosina Voigtlander NOKTON 35mm F/1.4 VM||M||8 - 6||0.7m||⌀43||2008 ●|
|Cosina Voigtlander NOKTON 40mm F/1.4 VM||M||7 - 6||0.7m||⌀43||2004 ●|
|Cosina Voigtlander ULTRON 35mm F/1.7 Aspherical VM||M||9 - 7||0.5m||⌀46||2015 ●|
|Cosina Voigtlander NOKTON 35mm F/1.2 Aspherical VM||M||10 - 7||0.7m||⌀52||2003 ●|
|Cosina Voigtlander ULTRON 35mm F/2 Aspherical VM Type 1||M||8 - 5||0.58m||⌀39||2018 ●|
|Cosina Voigtlander NOKTON 40mm F/1.2 Aspherical VM||M||8 - 6||0.5m||⌀52||2017 ●|
|Cosina Voigtlander NOKTON 35mm F/1.4 II VM||M||8 - 6||0.7m||⌀43||2019 ●|
|Cosina Voigtlander NOKTON 35mm F/1.2 Aspherical III VM||M||9 - 7||0.5m||⌀52||2020 ●|
|Cosina Voigtlander ULTRON 35mm F/2 Aspherical VM Type 2||M||8 - 5||0.58m||⌀39||2021 ●|
|Cosina Voigtlander APO-LANTHAR 35mm F/2 Aspherical VM||M||11 - 9||0.5m||⌀49||2021 ●|
|Cosina Voigtlander HELIAR 40mm F/2.8 Aspherical VM • Pancake lens||M||5 - 3||0.7m||⌀34||2022 ●|
|Cosina Voigtlander NOKTON 35mm F/1.5 Aspherical VM Type 1||M||9 - 6||0.5m||⌀39||2022 ●|
|Cosina Voigtlander NOKTON 35mm F/1.5 Aspherical VM Type 2||M||9 - 6||0.5m||⌀39||2022 ●|
|Konica M-HEXANON 35mm F/2||M||8 - 7||0.7m||⌀46||2001 ●|
|Leitz Wetzlar SUMMICRON-C 40mm F/2 • Pancake lens||M||6 - 4||0.8m||S.5.5||1973 ●|
|Leitz Wetzlar ELMARIT-C 40mm F/2.8||M||4 - 3||0.8m||S.5.5||1973 ●|
|Minolta M-ROKKOR 40mm F/2 [CLE] • Pancake lens||M||6 - 4||0.8m||⌀40.5||1980 ●|
|Minolta M-ROKKOR 40mm F/2 [CL] • Pancake lens||M||6 - 4||0.8m||⌀40.5||1972 ●|
|Carl Zeiss Biogon T* 35mm F/2 ZM||M||9 - 6||0.7m||E43||2004 ●|
|Carl Zeiss C Biogon T* 35mm F/2.8 ZM||M||7 - 5||0.7m||E43||2008 ●|
|ZEISS Distagon T* 35mm F/1.4 ZM||M||10 - 7||0.7m||E49||2014 ●|
|Canon 35mm F/1.5 [LSM]||M||8 - 4||1m||⌀48||1958 ●|
|Canon 35mm F/1.8 [LSM]||M||7 - 4||1m||S.VI||1957 ●|
|Canon 35mm F/2 [LSM]||M||7 - 4||1m||⌀40||1962 ●|
|Canon SERENAR 35mm F/2.8 I [LSM] • Pancake lens||M||6 - 4||1m||S.VI||1951 ●|
|Canon 35mm F/2.8 II [LSM]||M||6 - 4||1m||⌀40||1957 ●|
|Canon SERENAR 35mm F/3.2 [LSM] • Pancake lens||M||6 - 4||1.0668m||S.VI||1951 ●|
|Canon SERENAR 35mm F/3.5 [LSM]||M||4 - 3||1.0668m||S.VI||1950 ●|
|Chiyoko ROKKOR 35mm F/3.5 [C] [LSM]||M||4 - 3||1m||⌀34||1956 ●|
|Cosina Voigtlander Color-SKOPAR 35mm F/2.5 P MC [LSM] • Pancake lens||M||7 - 5||0.9m||⌀39||2000 ●|
|Cosina Voigtlander Color-SKOPAR 35mm F/2.5 MC [LSM]||M||7 - 5||0.7m||⌀39||2000 ●|
|Cosina Voigtlander ULTRON 35mm F/1.7 Aspherical [LSM]||M||8 - 6||0.9m||⌀39||1999 ●|
|Cosina Voigtlander HELIAR 40mm F/2.8 Aspherical [LSM] • Pancake lens||M||5 - 3||0.7m||⌀34||2022 ●|
|Fuji Photo Film FUJINON 35mm F/2 [LSM]||M||7 - 5||1m||1954 ●|
|Konica HEXANON 35mm F/2 (1000 units) [LSM]||M||7 - 6||0.9m||⌀46||1996 ●|
|Konica UC-HEXANON 35mm F/2 (1000 units) [LSM] • Pancake lens||M||7 - 6||0.9m||⌀43||2001 ●|
|Leitz Wetzlar SUMMARON 35mm F/3.5 (up to s/n 1,423,140)||M||6 - 4||1m||A36||1950 ●|
|Leitz ELMAR 35mm F/3.5||M||4 - 3||1m||A36||1930 ●|
|Leitz Wetzlar SUMMARON 35mm F/2.8||M||6 - 4||1m||E39||1958 ●|
|Leitz Wetzlar / Leitz Canada SUMMICRON 35mm F/2 [I]||M||8 - 6||1m||E39||1958 ●|
|Leitz Wetzlar SUMMARON 35mm F/3.5 (from s/n 1,423,141)||M||6 - 4||1m||E39||1956 ●|
|Nikon W-NIKKOR[·C] 35mm F/3.5 [LSM]||M||4 - 3||0.9m||⌀34.5||●|
|Nikon W-NIKKOR[·C] 35mm F/2.5 [LSM]||M||6 - 4||0.9m||⌀34.5||●|
|Nikon W-NIKKOR[·C] 35mm F/1.8 [LSM]||M||7 - 5||0.9m||⌀43||●|
|Olympus ZUIKO C. 40mm F/2.8 [LSM]||M||5 - 4||1950 ●|
|P. Angenieux Paris 35mm F/2.5 [Retrofocus] Type R1||M||6 - 5||1950 ●|
|P. Angenieux Paris 35mm F/3.5 Type X1||M||4 - 3||1m||●|
|Rollei HFT Sonnar 40mm F/2.8 (430 units) [LSM]||M||5 - 4||0.7m||⌀39||2002 ●|
|Sankyo Kohki W-Komura 35mm F/2.8 [LSM]||M||6 - 4||1m||⌀43||●|
|Sankyo Kohki W-Komura 36mm F/1.8 [LSM]||M||7 - 5||1m||⌀58||●|
|Sankyo Kohki W-Komura 35mm F/3.5 [LSM]||M||5 - 4||1m||⌀34||●|
|Schneider-Kreuznach Xenogon 35mm F/2.8 [LSM]||M||6 - ?||1.1m||S.V||●|
|Teikoku Kogaku (Zunow Opt.) ZUNOW 35mm F/1.7||M||7 - 5||1m||⌀46||●|
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For SUMMARON 3.5cm and SUMMICRON 5cm with E39 mounts. Velvet lining for reverse positioning. Narrow chrome band with above lens names engraved on black conical portion.
For 50mm and 35mm lenses with E39 mount. Double trigger fastening. Wide chrome band. Earliest examples were engraved "Summaron 3.5cm Summicron 5cm" but no codeword; later ones were engraved with either four or six focal length/aperture combinations and the codeword. Latest ones had the catalogue number and six focal length/aperture combinations.
For all 35mm and 50mm lenses with 42mm external mount diameter. All black. Engraved with either five or six focal length/aperture combinations and the catalogue number.
Replacement lens cap, screw-in type. Fits lenses with 42mm flange diameter.
Replacement rear cover, plastic, for Leica M-mount lenses (except 21mm lens) and Visoflex.
Replacement lens cap, chrome plated, fitting the 50mm SUMMICRON and all Leica lenses with 42mm flange diameter.
Replacement lens cap for SUMMICRON 35mm f/2 [II, III], SUMMICRON-M 35mm f/2 [II], SUMMARON 35mm f/2.8, SUMMARON 35mm f/2.8 with OVU, SUMMILUX[-M] 35mm f/1.4 [II], ELMAR 50mm f/2.8 [I], SUMMICRON-M 50mm f/2 [IV], TELE-ELMARIT 90mm f/2.8 [I], HEKTOR 135mm f/4, TELE-ELMARIT-M 90mm f/2.8 [II], TELE-ELMAR 135mm f/4 Type 1.
Replacement rear cover for Leica M-mount lenses.
You are already on the page dedicated to this lens.
Cannot compare the lens to itself.
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.
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 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 – 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.
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.
The minimum distance from the focal plane (film or sensor) to the subject where the lens is still able to focus.
The distance from the front edge of the lens to the subject at the maximum magnification.
Determines how large the subject will appear in the final image. 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".
The diaphragm must be stopped down manually by rotating the detent aperture ring.
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.
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.
The camera automatically closes the diaphragm down during the shutter operation. On completion of the exposure, the diaphragm re-opens to its maximum value.
The aperture setting is fixed at F/2.8 on this lens, and cannot be adjusted.
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.).
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.
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.
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.
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.
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.