Macro photography

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Macro photograph of a common yellow dung fly (Scathophaga stercoraria) made using a lens at its maximum 1:1 reproduction ratio, and an 18x24mm image sensor, the on-screen display of the photograph results in a greater than life-size image. Scatophaga stercoraria macro Luc Viatour.jpg
Macro photograph of a common yellow dung fly (Scathophaga stercoraria) made using a lens at its maximum 1:1 reproduction ratio, and an 18×24mm image sensor, the on-screen display of the photograph results in a greater than life-size image.
Headshot of a dragonfly taken with a 100 mm macro lens coupled with a 50 mm lens in reverse at the end. Dragon Fly portrait using reverse ring macro.png
Headshot of a dragonfly taken with a 100 mm macro lens coupled with a 50 mm lens in reverse at the end.
Macro photograph of an ant Formica polyctena 2.jpg
Macro photograph of an ant

Macro photography (or photomacrography [1] [2] or macrography, [3] and sometimes macrophotography [4] ) is extreme close-up photography, usually of very small subjects and living organisms like insects, in which the size of the subject in the photograph is greater than life size (though macrophotography also refers to the art of making very large photographs). [3] [5] By the original definition, a macro photograph is one in which the size of the subject on the negative or image sensor is life size or greater. [6] In some senses, however, it refers to a finished photograph of a subject that is greater than life size. [7]

Contents

The ratio of the subject size on the film plane (or sensor plane) to the actual subject size is known as the reproduction ratio. Likewise, a macro lens is classically a lens capable of reproduction ratios of at least 1:1, although it often refers to any lens with a large reproduction ratio, despite rarely exceeding 1:1. [7] [8] [9] [10]

Apart from technical photography and film-based processes, where the size of the image on the negative or image sensor is the subject of discussion, the finished print or on-screen image more commonly lends a photograph its macro status. For example, when producing a 6×4-inch (15×10-cm) print using 35 format (36×24 mm) film or sensor, a life-size result is possible with a lens having only a 1:4 reproduction ratio. [11] [12]

Reproduction ratios much greater than 10:1 are considered to be photomicrography, often achieved with digital microscope (photomicrography should not be confused with microphotography, the art of making very small photographs, such as for microforms).

Due to advances in sensor technology, today's small-sensor digital cameras can rival the macro capabilities of a DSLR with a "true" macro lens, despite having a lower reproduction ratio, making macro photography more widely accessible at a lower cost. [9] [13] In the digital age, a "true" macro photograph can be more practically defined as a photograph with a vertical subject height of 24 mm or less. [14]

History

The term photo-macrograph was proposed in 1899 by W. H. Walmsley for close-up images with less than 10 diameters magnification, to distinguish from true photo-micrographs. [15]

One of the earliest pioneers of macro photography was Percy Smith, born in 1880. He was a British nature documentary filmmaker, and was known for his close-up photographs. [16]

Equipment and techniques

Canon MP-E 65 mm macro lens. Small front lens elements are typical of macro lenses. Canon MP-E65mm.jpg
Canon MP-E 65 mm macro lens. Small front lens elements are typical of macro lenses.
Extension tubes for extreme macro use with SLRs. Note the pen placed through the tube to illustrate that it does not contain any lens elements. ExtensionTube5733.jpg
Extension tubes for extreme macro use with SLRs. Note the pen placed through the tube to illustrate that it does not contain any lens elements.
Bellows fitted between an SLR and reversed lens Automatik-Balgengeraet mit Kamera, Objektiv und Umkehrring.jpg
Bellows fitted between an SLR and reversed lens
Typical close-up lens Close-Up lens Canon 500D 58 mm.jpg
Typical close-up lens
Wide-angle lens used as a reversed lens in front of a macro lens MacroPlusRetrolens.jpg
Wide-angle lens used as a reversed lens in front of a macro lens

"Macro" lenses specifically designed for close-up work, with a long barrel for close focusing and optimized for high reproduction ratios, are one of the most common tools for macro photography. (Unlike most other lens makers, Nikon designates its macro lenses as "Micro" because of their original use in making microform.) Most modern macro lenses can focus continuously to infinity as well and can provide excellent optical quality for normal photography. True macro lenses, such as the Canon MP-E 65 mm f/2.8 1-5x Macro or Minolta AF 3x-1x 1.7-2.8 Macro, can achieve higher magnification than life size, enabling photography of the structure of small insect eyes, snowflakes, and other minuscule objects. Others, such as the Infinity Photo-Optical's TS-160 can achieve magnifications from 0-18x on sensor, focusing from infinity down to 18 mm from the object.

Macro lenses of different focal lengths find different uses:

Extending the distance between the lens and the film or sensor, by inserting either extension tubes or a continuously adjustable bellows, is another equipment option for macro photography. The further the lens is from the film or sensor, the closer the focusing distance, the greater the magnification, and the darker the image given the same aperture. Tubes of various lengths can be stacked, decreasing lens-to-subject distance and increasing magnification. Bellows or tubes shorten the available maximum focus distance and make it impossible to focus to infinity.

Placing an auxiliary close-up lens (or close-up "filter") in front of the camera's lens is another option. Inexpensive screw-in or slip-on attachments provide close focusing. The possible quality is less than that of a dedicated macro lens or extension tubes, with some two-element versions being very good while many inexpensive single element lenses exhibit chromatic aberration and reduced sharpness of the resulting image. This method works with cameras that have fixed lenses, and is commonly used with bridge cameras. These lenses add diopters to the optical power of the lens, decreasing the minimum focusing distance, and allowing the camera to get closer to the subject. They are typically designated by their diopter, and can be stacked (with an additional loss of quality) to achieve the desired magnification.

Photographers may employ view camera movements and the Scheimpflug principle to place an object close to the lens in focus, while maintaining selective background focus. This technique requires the use of a view camera or perspective control lens with the ability to tilt the lens with respect to the film or sensor plane. Lenses such as the Nikon PC-E and Canon TS-E series, the Hartblei Super-Rotator, the Schneider Super Angulon, several Lensbaby models, the Zoerk Multi Focus System, and various tilt-shift adapters for medium format, allow the use of tilt in cameras with fixed lens mounts. Traditional view cameras permit such adjustment as part of their design.

Ordinary lenses can be used for macro photography by using a "reversing ring". This ring attaches to the filter thread on the front of a lens and makes it possible to attach the lens in reverse. Excellent quality results up to 4x life-size magnification are possible. For cameras with all-electronic communications between the lens and the camera body specialty reversing rings are available which preserve these communications. When used with extension tubes or bellows, a highly versatile, true macro (greater than life size) system can be assembled. Since non-macro lenses are optimized for small reproduction ratios, reversing the lens allows it to be used for reciprocally high ratios.

Macro photography may also be accomplished by mounting a lens in reverse, in front of a normally mounted lens of greater focal length, using a macro coupler which screws into the front filter threads of both lenses. This method allows most cameras to maintain the full function of electronic and mechanical communication with the normally mounted lens, for features such as open-aperture metering. The magnification ratio is calculated by dividing the focal length of the normally mounted lens by the focal length of the reversed lens (e.g., when an 18 mm lens is reverse mounted on a 300 mm lens the reproduction ratio is 16:1). The use of automatic focus is not advisable if the first lens is not of the internal-focusing type, as the extra weight of the reverse-mounted lens could damage the autofocus mechanism. Working distance is significantly less than the first lens.

Increasingly, macro photography is accomplished using compact digital cameras and small-sensor bridge cameras, combined with a high powered zoom lens and (optionally) a close-up diopter lens added to the front of the camera lens. The deep depth of field of these cameras is an advantage for macro work. [13] [17] The high pixel density and resolving power of these cameras' sensors enable them to capture very high levels of detail at a lower reproduction ratio than is needed for film or larger DSLR sensors (often at the cost of greater image noise). Despite the fact that many of these cameras come with a "macro mode" which does not qualify as true macro, some photographers are using the advantages of small sensor cameras to create macro images that rival or even surpass those from DSLRs. [13]

Macro photography can also be carried out by attaching a camera to one optical path of a binocular microscope (stereo microscope), making use of the optics of that instrument as the imaging lens for the system. Between approximately 1976 and 1993, the manufacturers Wild Heerbrugg (Switzerland) and subsequently, Leica Microsystems offered a dedicated microscopy system for macro photography, the macroscope line, with improved optical performance for photography at the expense of the stereo imaging facility of the stereo microscope; this system came with a range of dedicated stands, objective and supplementary lenses, and illumination systems. [18] Following its discontinuation in 1993, Leica continues to offer similar products under the names Z6 APO and Z16 APO. [19]

Macro photography techniques

35 mm equivalent magnification

35 mm equivalent magnification: The photograph on top was taken with a full-frame (35 mm) sensor digital SLR camera and a 100 mm macro lens at 1:1 magnification. The photograph on the bottom was taken with a Micro Four Thirds (2x crop) sensor camera and a 50 mm macro lens at 1:2 magnification. The subject height in both images is 24 mm. Photographs taken with these two set-ups will be practically indistinguishable at the same print size, lending the photograph on the bottom its 1:1 35 mm equivalent reproduction ratio status. 35mm Equivalent Reproduction Ratio.jpg
35 mm equivalent magnification: The photograph on top was taken with a full-frame (35 mm) sensor digital SLR camera and a 100 mm macro lens at 1:1 magnification. The photograph on the bottom was taken with a Micro Four Thirds (2x crop) sensor camera and a 50 mm macro lens at 1:2 magnification. The subject height in both images is 24 mm. Photographs taken with these two set-ups will be practically indistinguishable at the same print size, lending the photograph on the bottom its 1:1 35 mm equivalent reproduction ratio status.

35 mm equivalent magnification, or 35 mm equivalent reproduction ratio, is a measure that indicates the apparent magnification achieved with a small sensor format, or "crop sensor" digital camera compared to a 35 mm-based image enlarged to the same print size. [20] [21] The term is useful because many photographers are familiar with the 35 mm film format. [14] [22] [23] [24] [25] [26]

While a "true" macro lens is defined as a lens having a reproduction ratio of 1:1 on the film or sensor plane, with small sensor format digital cameras an actual reproduction ratio of 1:1 is rarely achieved or needed to take macro photographs. What macro photographers often care about more is simply knowing the size of the smallest object that can fill the frame. [9] For example, the 12 megapixel Micro Four Thirds Panasonic Lumix DMC-GH1 camera with a 2x crop sensor only requires a 1:2 reproduction ratio to take a picture with the same subject size, resolution, and apparent magnification as a 12 megapixel "full-frame" Nikon D700 camera, when the images are viewed on screen or printed at the same size. Thus a Four Thirds system macro lens like the Olympus Zuiko Digital 35 mm F3.5 Macro lens with a true maximum image magnification of 1.0x is rated as having a "2.0x 35 mm equivalent magnification". [27]

To calculate 35 mm equivalent reproduction ratio, simply multiply the actual maximum magnification of the lens by the 35 mm conversion factor, or "crop factor" of the camera. If the actual magnification and/or crop factor are unknown (such as is the case with many compact or point-and-shoot digital cameras), simply take a photograph of a mm ruler placed vertically in the frame focused at the maximum magnification distance of the lens and measure the height of the frame. Since the object height of a 1.0x magnified 35 mm film image is 24 mm, calculate 35 mm equivalent reproduction ratio and true reproduction ratio by using the following: [28]

(35 mm equivalent reproduction ratio) = 24 / (measured height in mm)
(True reproduction ratio) = (35 mm equivalent reproduction ratio) / Crop factor.

Since digital compact camera sensor sizes come in a wide diversity of sizes and camera manufacturers rarely publish the macro reproduction ratios for these cameras, a good rule of thumb is that whenever a 24 mm vertical object just fits, or is too tall to fit in the camera viewfinder, you are taking a macro photograph. [14]

35 mm equivalent reproduction ratio: the photograph on the left was taken with a Micro Four Thirds (2x crop) sensor camera and a 50 mm macro lens at 1:2 magnification. The photograph on the right was taken with a full-frame (35 mm) sensor digital SLR camera and a 100 mm macro lens at 1:1 magnification. The photographs are practically indistinguishable and therefore equivalent. As the images were taken at slightly different angles, the two images can be viewed as a cross-eyed stereogram. Full-Frame and Micro Four Thirds Macro Equivalent Images - Columbine Flower.jpg
35 mm equivalent reproduction ratio: the photograph on the left was taken with a Micro Four Thirds (2x crop) sensor camera and a 50 mm macro lens at 1:2 magnification. The photograph on the right was taken with a full-frame (35 mm) sensor digital SLR camera and a 100 mm macro lens at 1:1 magnification. The photographs are practically indistinguishable and therefore equivalent. As the images were taken at slightly different angles, the two images can be viewed as a cross-eyed stereogram.

Technical considerations

Depth of field

Shallow depth of field Housefly on a leaf crop.jpg
Shallow depth of field

Limited depth of field is an important consideration in macro photography. Depth of field is extremely small when focusing on close objects. A small aperture (high f-number) is often required to produce acceptable sharpness across a three-dimensional subject. This requires either a slow shutter speed, brilliant lighting, or a high ISO. Auxiliary lighting (such as from a flash unit), preferably a ring flash is often used (see Lighting section).

Like conventional lenses, macro lenses need light, and ideally would provide similar f/# to conventional lenses to provide similar exposure times. Macro lenses also have similar focal lengths, so the entrance pupil diameter is comparable to that of conventional lenses (e.g., a 100 mm f/2.8 lens has a 100 mm/2.8 = 35.7 mm entrance-pupil diameter). Because they focus at close subjects, the cone of light from a subject point to the entrance pupil is relatively obtuse (a relatively high subject numerical aperture to use microscopy terms), making the depth of field extraordinarily small. This makes it essential to focus critically on the most important part of the subject, as elements that are even a millimetre closer or farther from the focal plane might be noticeably blurred. Due to this, the use of a microscope stage is highly recommended for precise focus with large magnification such as photographing skin cells. Alternatively, more shots of the same subject can be made with slightly different focusing lengths and joined afterwards with specialized focus stacking software which picks out the sharpest parts of every image, artificially increasing depth of field.

Lighting

The problem of sufficiently and evenly lighting the subject can be difficult to overcome. Some cameras can focus on subjects so close that they touch the front of the lens. It is difficult to place a light between the camera and a subject that close, making extreme close-up photography impractical. A normal-focal-length macro lens (50 mm on a 35 mm camera) can focus so close that lighting remains difficult. To avoid this problem, many photographers use telephoto macro lenses, typically with focal lengths from about 100 to 200 mm. These are popular as they permit sufficient distance for lighting between the camera and the subject.

Ring flashes, with flash tubes arranged in a circle around the front of the lens, can be helpful in lighting at close distances. [29] Ring lights have emerged, using white LEDs to provide a continuous light source for macro photography, however they are not as bright as a ring flash and the white balance is very cool. [30]

Good results can also be obtained by using a flash diffuser. Homemade flash diffusers made out of white Styrofoam or plastic attached to a camera's built-in flash can also yield surprisingly good results by diffusing and softening the light, eliminating specular reflections and providing more even lighting.

See also

Related Research Articles

Single-lens reflex camera

A single-lens reflex camera (SLR) is a camera that typically uses a mirror and prism system that permits the photographer to view through the lens and see exactly what will be captured. With twin lens reflex and rangefinder cameras, the viewed image could be significantly different from the final image. When the shutter button is pressed on most SLRs, the mirror flips out of the light path, allowing light to pass through to the light receptor and the image to be captured.

Aperture Hole or opening through which light travels

In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane.

Rangefinder camera

A rangefinder camera is a camera fitted with a rangefinder, typically a split-image rangefinder: a range-finding focusing mechanism allowing the photographer to measure the subject distance and take photographs that are in sharp focus. Most varieties of rangefinder show two images of the same subject, one of which moves when a calibrated wheel is turned; when the two images coincide and fuse into one, the distance can be read off the wheel. Older, non-coupled rangefinder cameras display the focusing distance and require the photographer to transfer the value to the lens focus ring; cameras without built-in rangefinders could have an external rangefinder fitted into the accessory shoe. Earlier cameras of this type had separate viewfinder and rangefinder windows; later the rangefinder was incorporated into the viewfinder. More modern designs have rangefinders coupled to the focusing mechanism so that the lens is focused correctly when the rangefinder images fuse; compare with the focusing screen in non-autofocus SLRs.

The focal length of an optical system is a measure of how strongly the system converges or diverges light; it is the inverse of the system's optical power. A positive focal length indicates that a system converges light, while a negative focal length indicates that the system diverges light. A system with a shorter focal length bends the rays more sharply, bringing them to a focus in a shorter distance or diverging them more quickly. For the special case of a thin lens in air, a positive focal length is the distance over which initially collimated (parallel) rays are brought to a focus, or alternatively a negative focal length indicates how far in front of the lens a point source must be located to form a collimated beam. For more general optical systems, the focal length has no intuitive meaning; it is simply the inverse of the system's optical power.

Angle of view Angular extent of given scene imaged by camera

In photography, angle of view (AOV) 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.

In photography and cinematography, a normal lens is a lens that reproduces a field of view that appears "natural" to a human observer. In contrast, depth compression and expansion with shorter or longer focal lengths introduces noticeable, and sometimes disturbing, distortion.

Camera lens

A camera lens is an optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically.

Zoom lens Lens with a variable focal length

A zoom lens is a mechanical assembly of lens elements for which the focal length can be varied, as opposed to a fixed focal length (FFL) lens.

Four Thirds system digital camera sensor and lens mount format

The Four Thirds System is a standard created by Olympus and Eastman Kodak for digital single-lens reflex camera (DSLR) and mirrorless camera design and development.

Digital single-lens reflex camera Digital cameras combining the parts of a single-lens reflex camera and a digital camera back

A digital single-lens reflex camera is a digital camera that combines the optics and the mechanisms of a single-lens reflex camera with a digital imaging sensor.

Teleconverter

A teleconverter is a secondary lens mounted between a camera and a photographic lens which enlarges the central part of an image obtained by the lens. For example, a 2× teleconverter for a 35 mm camera enlarges the central 12×18 mm part of an image to the size of 24×36 mm in the standard 35 mm film format.

Crop factor

In digital photography, the crop factor, format factor, or focal length multiplier of an image sensor format is the ratio of the dimensions of a camera's imaging area compared to a reference format; most often, this term is applied to digital cameras, relative to 35 mm film format as a reference. In the case of digital cameras, the imaging device would be a digital sensor. The most commonly used definition of crop factor is the ratio of a 35 mm frame's diagonal (43.3 mm) to the diagonal of the image sensor in question; that is, CF=diag35mm / diagsensor. Given the same 3:2 aspect ratio as 35mm's 36 mm × 24 mm area, this is equivalent to the ratio of heights or ratio of widths; the ratio of sensor areas is the square of the crop factor.

Image stabilization

Image stabilization (IS) is a family of techniques that reduce blurring associated with the motion of a camera or other imaging device during exposure.

Tilt–shift photography Camera technique

Tilt–shift photography is the use of camera movements that change the orientation or position of the lens with respect to the film or image sensor on cameras.

Image sensor format

In digital photography, the image sensor format is the shape and size of the image sensor.

Close-up lens

In photography, a close-up lens is a simple secondary lens used to enable macro photography without requiring a specialised primary lens. They work like reading glasses, allowing a primary lens to focus more closely. Bringing the focus closer allows the photographer more possibilities.

Lenses for SLR and DSLR cameras

This article is about photographic lenses for single-lens reflex film cameras (SLRs) and digital single-lens reflex cameras (DSLRs). Emphasis is on modern lenses for 35 mm film SLRs and for DSLRs with sensor sizes less than or equal to 35 mm ("full-frame").

Micro Four Thirds system

The Micro Four Thirds system is a standard released by Olympus and Panasonic in 2008, for the design and development of mirrorless interchangeable lens digital cameras, camcorders and lenses. Camera bodies are available from Blackmagic, DJI, JVC, Kodak, Olympus, Panasonic, Sharp, and Xiaomi. MFT lenses are produced by Cosina Voigtländer, DJI, Kowa, Kodak, Mitakon, Olympus, Panasonic, Samyang, Sharp, Sigma, SLR Magic, Tamron, Tokina, Veydra, and Xiaomi, amongst others.

In photography, a long-focus lens is a camera lens which has a focal length that is longer than the diagonal measure of the film or sensor that receives its image. It is used to make distant objects appear magnified with magnification increasing as longer focal length lenses are used. A long-focus lens is one of three basic photographic lens types classified by relative focal length, the other two being a normal lens and a wide-angle lens. As with other types of camera lenses, the focal length is usually expressed in a millimeter value written on the lens, for example: a 500 mm lens. The most common type of long-focus lens is the telephoto lens, which incorporate a special lens group known as a telephoto group to make the physical length of the lens shorter than the focal length.

35 mm format

The 35 mm format, or simply 35 mm, is the common name for the 36×24 mm film format or image sensor format used in photography. It has an aspect ratio of 3:2, and a diagonal measurement of approximately 43 mm. It has been employed in countless photographic applications including single-lens reflex (SLR) cameras, rangefinder cameras, mirrorless interchangeable-lens digital cameras, digital SLRs, point-and-shoot film cameras, and disposable film cameras.

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