Minolta SRT101

35mm MF film SLR camera


Production details:
Announced:April 1966
System: Minolta SR (1958)
Maximum format:35mm full frame
Film type:135 cartridge-loaded film
Mount and Flange focal distance:Minolta SR [43.5mm]
Speeds:1 - 1/1000 + B
Exposure metering:Through-the-lens (TTL), open-aperture
Exposure modes:Manual
Physical characteristics:

Manufacturer description #1

Measuring exposure through the lens isn't new. What is new is doing so with unfailing accuracy, regardless of contrast between subject and background. This is what makes the Minolta SR-T 101 far more than a new 35mm single lens reflex with through-the-lens metering... and so practical in unusual lighting situations.

Exclusive "CLC" exposure measurement system. "CLC" stands for Contrast Light Compensator, a remarkable development that enables the Minolta SR-T 101 to achieve accuracy never before possible in a through-the-lens metering camera.

In the "CLC" system, two extremely sensitive cadmium sulphide cells are arranged in a unique "series" circuit that causes each cell to be influenced by the other. Instead of an "average" reading, which is based on equal measurement of light and dark areas, you get an adjusted reading that makes special allowance for the predominant area.

Thus, in high contrast or uneven light sitiations, "CLC" automatically compensates to prevent under-exposure of the darker area. And "CLC" achieves this unprecedented accuracy while reading the entire picture area... unlike "spot" systems which cover only a small part of the scene.

Maximum handling ease and speed. An exclusive viewfinder design permits composing, focusing, setting aperture and shutter speed without ever taking the Minolta SR-T 101 from your eye... and always at full aperture.

Correct exposure, based on through-the-lens measurement, is set as you align two indicators in the finder. Shutter speeds are shown on a scale in the viewfinder... but outside of the picture area. A fine microprism center spot permits critical focusing. Corner-to-corner brightness is unmatched by any other 35mm reflex.

Exposure is measured at maximum aperture. The Meter Coupled (MC) Rokkor 58mm f/1.4 lens stays at full aperture except during the instant of exposure. Only then does the diaphragm "close down" automatically to pre-set aperture... re-opening automatically for the next exposure. The finder is always at maximum brightness, regardless of aperture needed to obtain proper exposure. The same automatic diaphragm control is provided by six other new MC Rokkor lenses, from 28mm wide angle to 200mm telephoto.

A system of lenses and accessories. In addition to the new "MC" lenses, the Minolta SR-T 101 will accept any of the complete system of interchangeable Rokkor lenses. These include focal lengths from 18mm ultra-wide-angle to 1000mm super-telephoto, plus special optics for macro and zoom photography. Over 100 accessories provide virtually unlimited flexibility.

The Minolta SR-T 101 has everything you would expect in a fine 35mm reflex... and more. There is an instant-return mirror... oversized to eliminate vignetting with long lenses... and an independent mirror lock. Shutter speeds are from 1 to 1/1000th sec. plus Bulb, with X synch. at 1/60th sec. and FP synch. at all speeds. The film advance is geared and "offset" for rapid shooting. The ASA range, from 6 to 6,400, is wider than on any other through-the-lens metering camera. There are many more refinements too numerous to list.

Manufacturer description #2


The Minolta SR-T 101 is a 35mm camera not confined in any way by the limitations of most comparably priced through-the-Iens metering cameras. It incorporates every single feature necessary to the success of the accomplished photographer. It has many others unique to any single lens reflex camera you can buy today. Designed and built by experts who know precisely what a camera must accomplish to satisfy the thinking professional, the SR-T 101 is the total performance SLR.

As a versatile instrument for the serious photographer, the SLR camera with through-the-Iens light measuring and full complement of interchangeable lenses has no peer. The SR-T 101 is all this - and then some. Its through-the-Iens system is of the full-aperture measuring type, a method of determining correct exposure long favored and respected by professionals and amateurs alike. Moreover, to enhance the SR-T 101's uncommon capability, Minolta has called upon its extensive exposure meter manufacturing experience and created the most accurate means of determining accurate exposure ever built-in to a camera. Called "Contrast Light Compensator," the meter system retains all the advantages of the most precise methods of measuring exposure, yet does away with the majority of their disadvantages. Minolta can prove it.

An abundance of other features marks the SR-T 101 as one of the very few truly professional SLR cameras available at any price. But, above all, the supreme versatility of this camera as a "system" camera remains unaltered. The SR-T 101 accepts almost every Rokkor Lens (including a new and unusually fast 58 mm F1.2 lens) and many other fine Minolta attachments ever built for the SR series of cameras. It is now available with professional black or standard metallic body. And it is, without question, the easiest·to- handle, easiest-to-operate SLR you'll ever photograph with.


As in all fine Minolta cameras, the SR-T 101 has many superb functions and mechanisms which have been studied from the viewpoint of the ultimate camera user. One of the more valuable is the new CLC (Contrast Light Compensator) exposure measuring system - most accurate means of determining correct exposure ever built-in to a camera.

Since it performs many useful tasks for the photographer, CLC is necessarily a complicated principle, involving all the technical mumbo-jumbo of photoelectronics, physics and mathematics. But, simply and precisely, CLC is designed to provide unusually accurate through-the lens metering in high-contrast lighting situations, and it does this through a unique system of splitting the light which enters the lens. Remember that, under "normal" lighting circumstances, built-in CdS exposure meters function with remarkable accuracy. The sole catch is that the photographer is faced time and time again with lighting situations that are difficult to calculate. And, invariably, trouble in the form of under- or over-exposure results when he relies on his CdS meter to get a reliable reading in high-contrast light. All too often, he doesn't get it.

But CLC eliminates failures resulting from under-exposure of shadows or other dark areas. It doesn't give a brighter light reading than the real average (like some CdS meters do), nor does it require difficult calculations. It does provide automatic compensation for bright light readings and dark readings. No other through-the-Iens system does.

In the SR-T 101, two CdS cells are located on top of the pentaprism. One is near the exit node; the other directly opposite. These cells are linked electrically in a way that is totally unique to the SR-T 101. By taking simultaneous light readings of the many lighting areas of the photo subject, and by automatically calculating a near-perfect contrast ratio, CLC insures perfect exposure no matter what the lighting condition. At all times you get a sensitive and reliable exposure reading - and your photography is faster and far less complex. You can prove it for yourself by testing the remarkable SR-T 101.


Judged by any standards of photography, the SR-T 101 is an astoundingly capable camera. With its versatile complement of Rokkor Lenses and other fine Minolta accessories, it becomes an instrument capable of challenging - and mastering - any photographic situation imaginable.

More than 120 accessories and attachments may be used with the SR-T 101. Included are more than 30 interchangeable Rokkor Lenses, covering the full range 16mm fisheye ultra-wideangle to 1000mm super-telephoto, and zoom lenses from 50mm to 500mm.

Such is the excellence of Rokkor Lenses that they have earned immense popularity among photographers of all abilities - for the following reasons: Even brightness from corner to corner; superb color reproduction; high resolving power with sharp contrast between image and background; ability to allow photography of objects as they really exist; and convenient mechanisms and ease of handling. Made exclusively by Minolta for Minolta cameras, Rokkor Lenses are quality-controlled from raw materials to final, finished product. They are generally acknowledged to be one of the world's few great systems of photographic optics.

An exclusive feature of Rokkor Lenses is Minolta's patented Achromatic Coating process. This secret treatment is actually a double coating, which results in the famous "green lens" appearance. This double coating allows the entire light spectrum to pass throlJgh the lens. As a result, Rokkor Lenses give true color balance - better than any other lens manufactured today. Minolta guarantees it. And can, because Minolta standards for lens precision and perfection are the highest in the camera industry.


The principle of the through-the-Iens light measuring meter is hardly new. But the way Minolta has improved it in the SR-T 101 is new.

In all single lens reflex cameras, a photographer looking through the viewfinder sees the exact light condition and image that he'll ultimately record on film as he releases the shutter. When an ideal through- the-lens system is integrated into the camera, two additional things should occur: the exposure meter should receive as much light as the film surface, and the light receiving angle of the meter should correspond to the view angle of the taking lens.

Such a system has unqualified advantages. With it, the photographer need never worry about exposure factor when he changes lenses as the light receiving angle of this meter compensates for the change in all lenses. And he can do close-up or telephotography without making complex calculations.

The SR-T 101's through-the-Iens system does all this, and adds the benefit of precise exposure measurement with CLC. Its two CdS cells are located at the top of the pentaprism. Light rays brighter than the real average are minimized. Harmful, extraneous light which enters the taking lens is prevented by a light shield plate. Harmful incident light is prevented from entering through the eyepiece by a reflection absorption film and a shading mask.

In addition, the SR-T 101 has a full-aperture measuring system. Its CLC meter is coupled to the aperture and shutter speed setting. Focusing, viewing and exposure measuring is performed simultaneously with the lens open full. The viewfinder is always bright, corner-to-corner.

Minolta incorporated all these through-the-Iens advantages in its SR-T 101 without sacrificing convenience and ease-of-handling. Other through-the-Iens cameras couldn't do it, no matter what their price.


One of the truly important features of any outstanding through-the-lens metering camera, from the professional photographer's viewpoint, is full-aperture measurement. Minolta's SR-T 101 has it.

Keep in mind that on many through-the-lens cameras the visual field of view as you glance through the viewfinder becomes darker when the lens is "stopped down" for exposure measuring. Naturally, this makes accurate focusing, composing and measuring difficult. With the SR-T 101, the MC lens is completely automatic, and aperture is always at maximum opening until you release the shutter. This means even when you set the aperture when measuring exposure, the viewfinder remains at maximum brightness from corner to corner. You see clearly what you're shooting at all times. And focusing, composing and correct exposure measuring, even for a dark subject, is simple - precisely the way you want it to be to get perfect photographic results.

MC Rokkor Lenses are equipped with meter couplers for full-aperture measurement. The CLC meter in the camera is coupled to the aperture and shutter speed setting, and you obtain correct exposure from either setting.

But this entirely new camera does not obsolete the great SR system of Rokkor Lenses. Conventional Rokkor Lenses for the SR series also fit the SR-T 101.


Whether you're an amateur photographer or a veteran, you'll appreciate the unequalled control- integrated viewfinder of the SR-T 101. It provides more than ample information for any photographic situation other than flash - and you can make ALL necessary adjustments without ever taking your eye from the camera.


It provides a near-perfect field of vision. This means you see the subject exactly how it appears to the human eye.


The spot of slanted microprisms in the center of the finder snaps the image into crisp sharpness when perfect focus has been achieved. The Fresnel lens keeps the image bright out to each corner, an important factor for precise, easy picture composition.


The follow-up needle in the SR-T 101 viewfinder is exclusive - and new - with Minolta. With it, you can always determine the entire range of possible exposures at a glance.


At the lower part of the viewfinder is a convenient shutter speed indicator. It lets you change from one shutter speed to another without taking the camera from your eye. In fact, no matter what adjustment is necessary to insure perfect photo-taking, you can make it with the SR-T 101 - and your eye always is looking through the viewfinder. Can you think of another SLR camera at any price that has a similar feature?


While it extends your picture-taking capabilities, the SR-T 101 remains the easiest-to-handle through-the-lens SLR camera ever created. So far, nobody has made a more convenient, easier-to-use SLR.

Pick it up. Hold it in picture-taking position. Notice how the sleek, thin body fits easily, gracefully into the curve of your hands. The balance - so important to any camera - is perfect. With the SR-T 101, Minolta proves that professional SLR cameras don't have to be bulky, heavy or hard to handle.

The SR-T 101's full-aperture measurement system contributes to its ease of handling. Remember, cameras which use the stop-down measurement system require a hand-operated device for closing the diaphragm blades. The blades on the SR-T 101 stay wide open until you release the shutter, then they close automatically with Me Rokkor Lenses.

All controls of the SR-T 101 are positioned where you can read them, adjust them at a glance. What's more, with Minolta's new control-integrated viewfinder, you can operate everything - exposure setting, focus, shutter speed, aperture setting and framing - without taking the camera from your eye. There isn't another single lens reflex camera in the entire through-the-Iens field that can match this viewfinder for convenience.

The SR-T 101's easy-handling ability extends all the way to its versatile complement of interchangeable Rokkor Lenses. Each is bayonet-mounted. You can change from one to the other in a matter of seconds, without complicated adjustments.



Largest of any found in a SLR camera, the SR-T 101 mirror allows the photographer to view the full frame without annoying mirror cut-off of the image - even when medium to long telephoto lenses and close-up lenses are employed.


In most camera lenses, the corners of the viewfinder become darker than the center when the aperture is open wide. With SR-T 101 MC Rokkor Lenses, the full aperture scale is given vignetting correction for correct exposure. Accurate exposure measuring is thus possible at the maximum F-stop because these MC lenses compensate the distance between the F-number of the maximum open aperture and the next F-number to it.


All Rokkor Lenses (except close-up types) are bayonet-mounted. This is a quick, foolproof way to change lenses - and you can do it in seconds. At all times, the mount is rigid and smooth, without the slightest trace of looseness or "backlash" And this is an important consideration since rigidity of mount is essential to holding good picture definition. Another point: You can change from one lens to another without making annoying adjustments.


The SR-T 101 take-up film spool lets you load film quickly and safely. If you've ever been in a hurry to load a camera, you'll appreciate this feature.


The SR-T 101 accepts film from ASA 6-6400, making it versatile enough for any kind of photography.


Shutter speeds range from 1 to 1/1000 second plus B. All speeds are synchronized for FP bulbs: 1 to 1/60 for electronic flash.


Single lens reflex 35mm camera with through-the-lens CLC (Contrast Light Compensator) meter coupled to shutter and film speed. Working range is EV 3 to EV 17 at ASA 100. Standard Rokkor Lens 58mm F1.4 (or 58mm F1.2 or 55mm F1.7). Black or metallic body. Focal plane shutter with speeds from 1 to 1/1000 sec. plus B. Fine microprism focusing with Fresnel lens. Real image finder through the fixed, eye-level pentaprism. Exposure control needle and shutter speed are visible in finder. Flash synchronization (FP and X contact points). Single or several stroke rapid-wind film advance lever. Automatic reset film counter, rapid film-rewind crank, built-in self timer, bayonet type lens mount, accessory shoe. Accepts standard 35mm film (20 or 36 exposures) in ASA speeds 6-6400 (DIN 9-39). Built-in ASA-DIN converting table. Oversized quick return mirror with lock-up device.

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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.

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

Lens construction

Lens construction – a specific arrangement of elements and groups that make up the optical design, including type and size of elements, type of used materials etc.

Element - an individual piece of glass which makes up one component of a photographic lens. Photographic lenses are nearly always built up of multiple such elements.

Group – a cemented together pieces of glass which form a single unit or an individual piece of glass. The advantage is that there is no glass-air surfaces between cemented together pieces of glass, which reduces reflections.

Focal length

The focal length is the factor that determines the size of the image reproduced on the focal plane, picture angle which covers the area of the subject to be photographed, depth of field, etc.


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.


Excluding case or pouch, caps and other detachable accessories (lens hood, close-up adapter, tripod adapter etc.).

Maximum diameter x Length

Excluding case or pouch, caps and other detachable accessories (lens hood, close-up adapter, tripod adapter etc.).

For lenses with collapsible design, the length is indicated for the working (retracted) state.

Weather sealing

A rubber material which is inserted in between each externally exposed part (manual focus and zoom rings, buttons, switch panels etc.) to ensure it is properly sealed against dust and moisture.

Lenses that accept front mounted filters typically do not have gaskets behind the filter mount. It is recommended to use a filter for complete weather resistance when desired.

Fluorine coating

Helps keep lenses clean by reducing the possibility of dust and dirt adhering to the lens and by facilitating cleaning should the need arise. Applied to the outer surface of the front lens element over multi-coatings.


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.