Red-eye

Red-eye

An effect often caused by a camera’s built-in flash. The flashlight reflects from the retina of

the subjects’ eyes and gives them a bright red colour. It can be reduced or corrected in-camera, or at the post-processing stage.


 

 

The ABC of Photography – Z

The ABC of Photography – Z

ZA

Stands for Zeiss Alpha – a range of Sony lenses designed by Carl Zeiss.

Zone system

The Zone system is a systematic technique for calculating the best possible film exposure and development. It was formulated in around 1940 by photographers Ansel Adams (1902-84) and Fred Archer (1889-1963).

 

Zoom

A lens with a variable angle of view. On a zoom lens, the focal length can be changed while the focus remains the same.

Zoom ratio

The relationship between the shortest and longest focal length setting of a zoom lens. For example, a 14-42mm lens has a zoom ratio of 3:1, or 3x; a 50– 500mm lens has a zoom ratio of 10:1, or 10x.

Sources:  Pixabay, NASA,Wikipedia, Susan Wingfield Lamar High School


 

The ABC of Photography – Y

The ABC of Photography – Y

 

Yellow filter

In film photography, yellow filters were often used by black-and-white landscape photographers to darken a blue sky and brighten the landscape.

 

Yevonde, Madame

Madame Yevonde (1893-1975) popularized the use of colour in portrait photography in the early 1930s. She’s most famous for her studio portraits of the mid-1930s that made creative use of costumes and props.

 

Sources:  Pixabay, NASA, Wikipedia, Susan Wingfield Lamar High School


 

The ABC of Photography – X

The ABC of Photography – X

 

XLD

Stands for extra-low dispersion, the glass used in some Tamron lenses to reduce chromatic aberration.

XMP

Stands for an extensible metadata platform. A labeling technology used by a number of image-editing programs, including the Photoshop family. It records information about a file and is usually embedded within the file itself. With raw files, the XMP information is recorded separately.

XR

Stands for extra refractive, a type of glass used in Tamron lenses. It can bend light at wider angles than normal glass, helping to make the overall size of the lens smaller.

Sources:  Pixabay, NASA,Wikipedia, Susan Wingfield Lamar High School


 

The ABC of Photography – W

The ABC of Photography – W

 

Watermark

An element embedded in a digital image, such as a name or symbol, to show ownership and prevent images being used without the copyright owner’s permission. Weston, Edward (Edward Weston (1886-1958) was one of the major American fine-art photographers of the 20th century. His aim was, he said, to “make the commonplace unusual.” His photographs were clear and detailed representations of landscapes, portraits, nudes, and, most famously, still-life subjects such as seashells and peppers.

White balance

The digital camera system that sets the colour temperature for the scene being photographed. This can be set automatically, with the system attempting to set the colour so that it looks normal to the human eye. Most D-SLRs also offer a wide selection of manual white balance settings – where the WB can be set from a reference source (such as a piece of white card), or to a particular Kelvin value, or to a lighting type (such as sunny daylight or tungsten bulb lighting).

Wide-angle lens

A lens with a focal length shorter than the ‘normal’ lens (that is, the lens that gives the most true-to-life field of view) for a given format. In the 35mm format, focal lengths from 35mm to 24mm are considered wide-angle, while lenses from 21mm to 14mm are generally described as ultra-wide-angle.

Wratten number

A code for labeling optical filters, named after the inventor Frederick Wratten (1840-1926). Each separate colour has a number (orange filters, for example, have the number 81) and some have letters to indicate the strength of the filter (an 81EF is much stronger than an 81A, for example).

Sources:  Pixabay, NASA,Wikipedia, Susan Wingfield Lamar High School


 

The ABC of Photography – V

The ABC of Photography – V

 

Variable contrast

A type of photographic printing paper that, in the wet darkroom, allows a range of contrast grades to be produced by changing the colour of the filter in the enlarger head.

VC

Stands for vibration compensation, the name of the optical camera shake-reduction system on some Tamron lenses.

 

Vibrance

A slider is available in Adobe Camera Raw and Photoshop that enables you to increase the saturation of colours. It doesn’t increase saturation universally – it concentrates on colours that are not saturated already, with a more limited effect on colours that are already intense. This often leads to a more visually pleasing result.

View camera

A large-format film camera that uses sheet film. Depending on the camera design, film sizes can range from 5×4 inches to 20×24 inches. All view cameras have a front standard with a lens mount and a rear standard with a film holder and ground glass screen for focusing. Both standards can be moved backward and forwards and at different angles to alter perspective, focus, and depth of field. They are connected by a flexible and extendable bellow. View cameras can be used with digital backs instead of film.

Vignetting

Darkening of the corners of an image. This appearance is often deliberately created to highlight a subject in the center of the image and can be applied by digitally burning in corners. It’s also commonly seen in images taken with toy cameras such as the Holga. If vignetting is unintended, it’s usually due to lens fall-off, and can be corrected using post-processing software.

VR

Stands for vibration reduction, Nikon’s name for its image-stabilization system.

Sources:  Pixabay, NASA, Wikipedia, Susan Wingfield Lamar High School


 

The ABC of Photography – U

The ABC of Photography – U

 

UD

Stands for ultra-low dispersion, a type of glass used in Canon lenses to reduce chromatic aberration in the image.

Umbrella

An umbrella is used in a studio to reflect and diffuse light from a flash unit, creating a softer and more even light. The most common types are the white shoot-through umbrella, which is used between the flash and the subject, or the black umbrella with reflective silver or white underside that bounces flashlight back on to the subject.

Under-exposure

An insufficient exposure for the subject to retain all the shadow details so that darker areas become black or almost black. The greater the under-exposure, the darker the image. This may be a conscious choice for artistic reasons.

Underwater housing

A sealed container specifically made to protect particular cameras from damage in underwater photography, and that allows controls to be accessed and operated as normal.

Unsharp Mask

One of the most popular Photoshop tools for increasing sharpness in a digital image. It gets its curious name from a traditional print process, where a soft-focus negative is sandwiched with the sharp original in order to increase edge contrast.

USB 3.0

The third version of the Universal Serial Bus standard for connection and communication between computer peripherals (including digital cameras and printers) and personal computers. It was released in 2008 and was further updated to USB 3.1 in 2013.

USD

Stands for ultrasonic silent drive, Tamron’s fast, quiet AF motor.

USM

Stands for ultrasonic motor, a fast, low-noise autofocus motor used by some Canon lenses.

UV filter

An optical filter that absorbs ultraviolet (UV) radiation. It can be used to improve visibility and quality in a mountain and maritime landscapes. Many use them to protect the front of the lens.

Sources:  Pixabay, NASA, Wikipedia, Susan Wingfield Lamar High School


 

The ABC of Photography – T

The ABC of Photography – T

T

  

Table-top photography

Images of small objects or a miniature scene arranged on a tabletop.

Teleconverter

A supplementary lens used between a primary lens and the camera body to increase the focal length range of the primary lens. For example, a 1.4 teleconverter on a 200mm lens will increase the focal length to 280mm but causes a corresponding reduction in the maximum aperture size.

Telephoto

A term generally used to describe any long-focus lens (in 35mm photography, a lens with a focal length of 85mm upwards). However, telephoto technically refers to a long-focus lens in which the physical length of the lens is shorter than its focal length, a design feat achieved by its internal lens assembly.

Terabyte (TB)

Unit for measuring computer memory or disk storage capacity, which is roughly equivalent to 1,000 gigabytes. TFT (thin-film transistor) High-quality colour LCD technology, widely used for rear displays on digital cameras.

Thumbnail

A small, low-resolution version of a larger image. It’s often used in image management applications such as Adobe Bridge and Organizer to make it easier and faster to search through and preview your photo collection. The small representations of each layer in the Layers panel in Photoshop and similar software are also referred to as thumbnails.

Three-quarters lighting

Used in portraiture, this style of lighting is created by placing a light at approximately 45 degrees from each side of the centre line of the face. It lights three-quarters of the face, leaving a shadow area along the side opposite to the light that gives the face depth and volume.

TIFF (Tagged Image File Format)

Digital image format used to record files with maximum available detail. Files can be large, although this can be reduced using lossless compression.

Time-lapse

The technique where pictures are taken of the same subject at regular intervals. Some time-lapse photographers record an event that takes place over a long period of time, such as a butterfly emerging from a chrysalis.

TLR

Stands for twin-lens reflex. A TLR camera has two lenses of the same focal length; one is used for taking the picture while the other provides the image for the waist-level viewfinder, seen via a 45-degree mirror. The two lenses are connected so that focusing is the same on both lenses.

Tog

Short form for ‘photographer’.

Tone mapping

A technique used in image processing to reduce the range of tonal values in a high dynamic range image, so it looks more natural when shown on a computer monitor or in print.

Toning

Changing the colour of a black-and-white print or digital image. In traditional photography, black-and-white prints are usually toned using chemicals to change the metallic silver in the print emulsion to a silver compound. This happens in sepia and selenium toning. Other processes, such as platinum and gold toning, are known as metal-replacement toners. Similar effects can be produced in digital images using post-processing techniques.

Toy camera

An inexpensive and easy-to-use film camera, such as the Holga, Lubitel, Lomo LC-A and Diana. Their lens quality and general build lead to vignetting, image blur, distortion, and light leaks, but many photographers enjoy incorporating these flaws into their images for artistic effect.

Transform

A Photoshop tool used to scale, rotate, reduce, enlarge, distort, or change the perspective of a layer, selection, or shape.

Travel photography

A genre of photography that concentrates on documenting the landscape, people, culture, and customs of a country.

Tripod

Three-legged camera support.

 

Tripod bush

Threaded socket found on the base of cameras, used for attaching tripods and other accessories.

TS-E

Tilt-shift electronic – Canon’s range of perspective control lenses.

(See PC-E.)

TTL

(through the lens) metering An exposure metering system in which the intensity of light is measured through the camera lens.

Tungsten lighting

A type of bulb lighting that has a warm colour temperature of between 2,600 and 3,500K.

 

Tv (time value)

Abbreviation used for shutter priority on some cameras.

Sources:  Pixabay, NASA,Wikipedia, Susan Wingfield Lamar High School


 

The ABC of Photography – S

S

 

Sabattier effect

A wet darkroom effect in which an image is processed so that it’s partly a normal positive image and partly a negative. It was first described in the 1860s but became well-known in the work of Man Ray (1890-1976). His assistant, Lee Miller (1907-1977) accidentally turned on a light while developing a print, but Ray liked the effect and consciously used it in his work. He called it “solarization”. The Sabattier effect is easily recreated using Photoshop and looks best applied to a black-and-white image.

Safelight

A red/orange lamp used to light a traditional wet darkroom when printing black-and-white photographs. It’s safe to use at the printing stage because the photographic paper isn’t sensitive to red/orange light.

SAM

Stands for smooth autofocus motor, which has been used in recent Sony Alpha lenses.

Saturation

The strength of a colour or hue. An increase in saturation gives more intense colour. Too much saturation and the image will look unreal. An image with no saturation whatsoever will be black and white.


Scale

Scale gives us a sense of the size of an object or environment in an image, by using another object in the scene as a frame of reference. For example, by including a person in a landscape, the viewer is given a strong idea of the relative size of that landscape.

Scheimpflug principle

Theodor Scheimpflug (1865-1911) stated: “If the lens plane is tilted down, when the extended lines from the lens plane, the object plane, and the film plane intersect at the same point, the entire subject plane is in focus.” This principle comes into play when using tilt-shift lenses or tilt-and-swing movements on view cameras. In practice, it means that if you’re photographing a landscape, the lens can be tilted forwards until the plane of focus runs parallel to the ground. As a result, the depth of field is vastly increased, even when shooting with the lens wide open.

Scratch disk

Hard disk space used by Photoshop while processing an image to temporarily store information and make the process faster. It’s used, for example, to store the history states that are essential for using the History panel.

Screen grab

Also called a screenshot or screen capture, this is an image of all or part of a computer monitor display that can be saved as a graphics file.

SD

Super-low dispersion, the glass used in Tokina lenses to reduce chromatic aberration.

SD (Secure Digital) card

A type of removable memory card used in some digital cameras. SD cards (up to 32GB).

SDHC (Secure Digital High Capacity)

A type of SD card that has a higher maximum capacity than standard

SDM

Supersonic drive motor, Pentax’s fast, quiet focus motor.

SDXC (Secure Digital Extended Capacity)

A type of SD card that has an even higher maximum capacity than SDHC cards (up to 2TB).

Second curtain sync

An alternative term for rear- curtain sync.

Secondary mirror

A mirror used in digital SLRs to project some of the light passing through the lens to exposure and autofocus sensors.

Selenium tone

A chemical treatment applied to a silver-based black-and-white print in a wet darkroom that changes some of the metallic silver to silver selenide. Depending on dilution and the type of printing paper, tones may range from red-brown to purple-brown. The appearance of the effect can now be simulated in post-capture software on a computer. Photoshop CS6 and CC includes selenium toning among its range of toning presets.

Selfie

A modern term for self-portrait, a genre becoming increasingly popular in the age of the smartphone camera.

Self-timer

A camera facility that incorporates a delay between the pressing of the trigger and the beginning of the exposure. It has traditionally been used to enable the photographer to appear in the shot. It can also be used as a way of minimizing the vibration caused by pressing the camera shutter, when shooting an long exposure with the camera mounted on a monopod or tripod.

Sensor size

The dimensions of the CCD or CMOS sensor in a digital camera vary greatly according to the type of camera. This has a major impact on image quality. Larger sensors collect more light and produce images with greater dynamic range and less noise than smaller sensors.  Smartphone camera sensors measure around 4.5 x 3.4mm; compact camera sensors are around 6.1 x 4.5mm; D-SLR sensors are around 23.5 x 15.6mm, while a ‘full frame’ 35mm sensor measures around 36 x 24mm. A medium-format sensor (such as in the Pentax 645Z) measures around 44 x 33mm.

Sepia tone

A chemical treatment used in traditional photography that converts metallic silver in a black-and-white photograph to silver sulphide. It has the effect of changing shades of grey into shades of reddish-brown. The appearance can easily be created in digital images, either in-camera or using Photoshop. 720p A high-definition video recording format with a resolution of 1,280 x 720 pixels, offered on many of the more recent digital cameras.

Sharpening

Sharpening boosts the contrast around the edges of objects to increase definition, which helps counter the inherent softening effect of digital capture. Inkjet printing has a further softening effect, so if you’re going to print your image, it will need more sharpening than it would need for on-screen viewing.

Sheet film

Film used in large-format cameras, including 5×4 and 10×8 equipment, which is supplied in boxes of individual sheets.

Shift lens

An interchangeable lens available for a small number of D-SLRs and medium-format cameras. The lens provides a limited range of camera movements, including a facility for the lens to be shifted upwards to avoid converging verticals when photographing tall subjects, especially buildings. Also known as a PC lens.

 

Shutter

A device for allowing light to pass through a camera lens to the digital sensor or film, usually for a precise period of time. See also leaf shutter and focal plane shutter.

Shutter lag

The delay between the photographer physically pressing the shutter and the exposure actually being made.

Shutter priority

A semi-automatic exposure mode in which the shutter speed is set by the photographer. The aperture is then set by the camera to suit the metered light readings taken by the camera.

Shutter speed

Also called exposure time, this is the length of time the camera’s shutter is open to allow light coming through the lens to reach the image sensor or film.

Side lighting

This is illuminating a subject from one side across the camera axis, either using natural or artificial light, while the other side remains in shadow. It’s often used in portraiture to give texture and depth to a subject. It can give a dramatic look, especially against a dark background. If desired, shadow areas can be lightened by using a reflector.

Silver halide

The light-sensitive chemical compound that, when coated on photographic film or paper, enables images to be recorded.

Single lens reflex (SLR)

A camera that uses a pentaprism and mirror to show the exact image being seen through the lens. When the shutter is released, the mirror flips up to allow the image to pass through to the sensor or film.

Slave

Device that triggers a flash unit automatically when another flash is fired. The slave uses a light-sensitive photoelectric cell, and cuts down on the number of cables needed in a studio.

SLD

Stands for super-low dispersion – lens elements in Sigma lenses that reduce chromatic aberration.

Slow lens

A lens with a narrower than average maximum aperture for the focal length. As a result, shutter speeds at the maximum aperture are longer than with ‘faster’ lenses.

Slow sync flash

The technique in which slow shutter speed is used in conjunction with flash. The flash usually provides the main source of illumination, but the ambient light creates a secondary exposure that can be useful in suggesting movement, or for providing detail in a background that would otherwise have looked unnaturally dark.

SLT

Stands for Single Lens Translucent. This is a proprietary name for Sony Alpha cameras that use a pellicle (fixed, translucent) mirror, electronic viewfinder, and phase-detection autofocus system.

Smc

Stands for super multi-coating, a seven-layer coating used on Pentax lenses to reduce light reflected by the lens itself.

Snapshot aesthetic

A style of fine-art photography that uses a seemingly casual, snapshot appearance, and focuses on the everyday subject matter. Photographers using this approach have included William Eggleston (born 1939), Nan Goldin (born 1953), and Wolfgang Tillmans (born 1968). It was particularly popular in the 1990s fashion photography.

Snoot

A tube-like attachment in the shape of a cone or cylinder, which fits on the front of a flash unit or studio light. It enables the photographer to control the direction and width of the light so that it concentrates on, or isolates a subject.

Social documentary

The photographic genre that concentrates on recording the everyday lives of people from different nationalities, cultures, and social classes. Social documentary projects often have a particular purpose, such as the photographs of Lewis Hine (1874-1940) highlighting child labour in the early part of the 20th century, or Sebastião Salgado’s 1993 project on the conditions endured by workers in different countries around the world.

Softbox

An enclosure around a flash or continuous light. The insides are lined with reflective material while the square or round front screen is made of a white opaque material that diffuses and softens the light. Softboxes can measure anything from 40cm to 2m across the front.

Soft focus

Slightly blurred and lacking in sharp definition. Images can be ‘soft’ due to a lens flaw or made deliberately so to give a romantic ‘glow’ to an image. It can be achieved in-camera by attaching a soft-focus or diffuser filter to the lens, or by shooting through a piece of translucent material (for example, a section cut out from a pair of tights). It can also easily be added using post-capture software on a computer.

Solarisation

See Sabattier effect. Susan Sontag (1933-2004) was an American writer, filmmaker and

prominent activist, whose series of essays collected in the book, On Photography (1977), was a groundbreaking critique of the photographic medium.

SP

Stands for super performance, a long-standing tag found on top-of-the-range Tamron lenses.

Spot meter

Exposure metering system in which a meter reading is taken from a very small area in the centre of the frame.

sRGB

RGB colour space frequently used by digital cameras, but providing a narrower range of colours than the Adobe RGB space.

SSM

Stands for supersonic motor, used for high-speed autofocus in top-of-the-range Sony lenses.

Standard lens

A focal length of the lens is roughly equal to the diagonal of the image sensor area. Typically, standard lenses have an effective focal length of around 50mm.

Steichen, Edward

Edward Steichen (1879-1973) was an American fashion and portrait photographer. As Chief Photographer at Condé Nast publications in the 1920s and 1930s, he was the most famous(and reputedly the highest paid) photographer in the world. He was Director of Photography at the Museum of Modern Art in New York from 1947-1962 and in 1955 organized the Family of Man exhibition, seen by over nine million people.

Still-life photography

Following in the centuries-old tradition of still-life painting, still-life photographs focus on single or small groups of objects. They can be shot indoors or outdoors, using daylight or artificial light, and are usually carefully arranged by the photographer. Notable still-life photographers include Edward Weston (1886-1958) and Irving Penn (1917-2009).

Street photography

Photographs taken in public places that record human behavior or interaction in a way that comments on society or life in general. Street photographers aim to capture life as it happens and usually take pictures when people are unaware. Those who have worked in this broad genre include Henri Cartier-Bresson (1908-2004), Robert Frank (born 1924), and Garry Winogrand (1928-1884).

Stieglitz, Alfred

An important advocate for photography as an artistic medium, Stieglitz (1864-1946) formed the Camera Club of New York in 1896 and edited the magazine Camera Notes. He formed the Photo-Secession in 1902, a group of leading Photographers that argued that artistic expression was the most important thing about photography. His ideas influenced a generation of photographers.

Stitching

Combining two or more overlapping images of a subject to create one seamless panoramic or high-resolution image. It can be achieved via dedicated software programs such as Auto stitch or Canon’s Photo stitch or using the Photo merge feature in Photoshop.

Stop

A unit of exposure. Changing exposure by a single stop is equivalent to doubling or halving the amount of light reaching the image sensor. The distance between each of the standard aperture settings (f/2.8, f/4, f/5.6, f/8, f/16, etc.) is a full stop. Digital SLRs usually provide a number of intermediate half-stop or third-stop settings.

Stop down

Close down the camera’s aperture.

Strobe light

Also called a stroboscopic lamp, this light source produces flashes of light (usually around 200 microseconds in length) at regular intervals. In photography, it’s been used to make high-speed images of subjects that move too fast for the eye to see, such as a bullet zipping through the air. Strobe lights have also been used to capture multiple images of a moving subject in one image, for example in the photographs of dancers by Gjon Mili (1904-1984).

Superzoom

A lens with an unusually large focal length range. Current super zoom examples available for D-SLR cameras include the Tamron 80-270mm f/3.5-6.3 and the Sigma 18-200mm f/3.5-6.3. Some of the largest superzooms are found on bridge cameras; the Panasonic Lumix DMC-FZ70 has a 60x optical zoom, for example, which is equivalent to 20- 1,200mm. Bridge cameras themselves are sometimes called ‘superzooms’ or ‘ultrazooms’. See the bridge camera.

Swinger, Polaroid

A name used on some of the affordable and easy-to-use range of instant cameras produced by the Polaroid Corporation in the 1960s and 1970s.

SWM

Silent wave motor, the high-speed quiet autofocus motor used on Nikon’s AF-S lenses.

Sync speed

The fastest shutter speed that can be set on a camera that enables synchronization with the flash. See flash synchronization.

Sources:  Pixabay, NASA, Wikipedia, Susan Wingfield Lamar High School


 

The ABC of Photography – R

R

Rangefinder

A camera with a separate lens and viewfinder, linked by a rangefinder mechanism. When looking through the viewfinder, two separate images are shown, one of which moves when the focus ring is turned. When the two superimposed images are perfectly aligned, the image is in focus.

Raw

A file format option provided by D-SLRs and some other top-end digital cameras. Image data is stored in a semi-processed state and needs to be fully processed on a computer. Raw files enable exposure compensation, image contrast, colour balance and other settings to be altered after the initial exposure, while still retaining maximum image quality. Raw images also offer a greater tonal range than the alternative JPEG recording quality options.

Raw isn’t an abbreviation or even a single file type like JPEG; the format varies from manufacturer to manufacturer, and sometimes from camera to camera. Most current Canon models use CR2, and Nikon models use NEF.

Rear-curtain sync

Flash feature found on some D-SLRs and flashguns that synchronizes the flash output when the second shutter curtain is about to close. Usually, the flash fires at the point where the first shutter is fully open. The facility gives more natural-looking images when using flash in conjunction with slow shutter speeds.

  Reciprocity

The reciprocity law states that the density of a photographic image is in direct proportion to the intensity of light (aperture setting) and the duration (shutter speed). For example, if the correct exposure for a subject is 1/125 sec at f/4 and the aperture is increased by one stop to f/2.8, the shutter speed must be correspondingly decreased by one stop to 1/60 sec to maintain the same image quality, and vice versa.

 

Reciprocity failure

In film photography, when shooting with very long or very short exposures, the reciprocity law (see above) can break down, leading to reciprocity failure. In these cases, extra exposure might be needed to compensate, as specified by the film manufacturer. Reciprocity failure doesn’t occur with digitally captured images.

Red-eye

An effect often caused by a camera’s built-in flash. The flash-light reflects from the retina of a subject’s eyes and gives them a bright red colour. It can be reduced or corrected in-camera, or at the post-processing stage.

Reflected light reading

The most frequently used type of exposure meter reading, which measures the amount of light reflecting from a subject. An alternative approach is to use an incident light meter, which measures the amount of light falling on a subject.

Reflector

A piece of card or other flat material that reflects and increases the amount of illumination from a light source. Reflectors can be white, silver or gold, and are often used to ‘bounce’ light into shadow areas and make them brighter. An umbrella-shaped reflector on a studio light is used to create softer and more diffuse illumination.

Rembrandt lighting

A studio portrait lighting technique named after the Dutch painter Rembrandt van Rijn (1606-1669), who often used it. It refers to lighting one side of the face so that it creates a triangle of light on the opposite cheek. A reflector is sometimes used to bounce light on to the side of the face in shadow.

 

 

Reportage

The act or technique of news reporting. In photography, the term refers to the art of telling a news story through pictures. Many wedding photographers offer ‘reportage style’ pictures. This simply means that the day’s events are approached as if it were a news event, and recorded in an informal and unobtrusive way. See photojournalism.

Resize

To create a new copy of an image with a different file size or resolution (pixel count).

Resolution

A measure of the density of pixels in a printed or on-screen image, usually expressed in terms of pixels per inch (ppi). A resolution of 300ppi is widely regarded as the optimum for professional-quality printing. Monitors typically display images at between 72 and 96ppi, although this can vary with monitor size and other factors. Changing a photo’s resolution in the Image Size dialog in Photoshop won’t change how big it looks on-screen, only in print.

RF

The rear focus feature is found on super telephoto lenses. With rear focus, the group of elements nearest the camera is used to determine the point of focus, providing faster autofocus.

RGB

Stands for red, green and blue. These are the three primary colours used by a digital camera to record a picture. Some tools can access and edit each of the three colour channels separately.

Rim lighting

Light from behind or to the side of a subject that gives a thin line of light around some or all of the subject’s edge, which sets it clearly apart from the background.

 Ring flash

A flash lighting system that uses a circular flash tube attached to the front of the lens to provide even, shadowless lighting. Ring flash is often used in macro photography, but is sometimes used in other kinds of photography including portraiture. Oversized ring flashes are available for studio use, providing doughnut-shaped catch lights when used for portraits.

 Rule of thirds

One of the best-known compositional ‘rules’, in which an image is divided, horizontally and vertically, into three parts, using two equally spaced lines. Important elements of the picture are then placed on one or more of these lines, which creates a stronger and more visually appealing composition than simply centering the subject. The term has its origins in painting, and was first written down by the artist John Thomas Smith in 1797.

Roll film

A photographic film wound on a spool and protected from light with a paper backing. The most commonly used type is a 120 roll film. It’s used in cameras shooting 6×4.5, 6×6, 6×7 and 6×9 negative sizes, plus panoramic cameras.

Sources:  Pixabay, NASA, Wikipedia, Susan Wingfield Lamar High School