Glossary

WHY A PHOTOGRAPHY GLOSSARY?

 

Photography is a bit tricky for most people. Especially when terms come up that you haven’t actually heard before. That’s why I think it’s important to give you a simple glossary. In the glossary below, you will find a brief description of subjects and / or terms most commonly used in photography in an alphabetical order.

 

ANTI-ALIASING

Aliasing is the jagged edge on curved lines or diagonals that becomes visible in extremely enlarged photos. Anti-aliasing is a technique to slightly smooth out this jagged edge.

 

ARTIFACTS

 

These are disturbing errors in a photo, caused, among other things, by an excessively high compression ratio in the JPEG format. For example, square areas of color can become visible in an even blue sky. Noise and halos are also artifacts.

AUTOFOCUS

An automatic system where the camera focuses on the subject, usually in the center of the frame. More advanced devices have the option to select other or additional focus areas.

APS

Advanced Photo System, this is a format of film cameras where the negative has dimensions of 25.1mm x 16.7mm. Many digital cameras have an APS-size sensor with roughly the same dimensions.

EXPOSURE

Allowing a certain amount of light for a certain amount of time on the image sensor.

The exposure values ​​measured by the camera may be incorrect due to circumstances. For example, photographing a snowy landscape can underexpose the camera. The photographer can respond to this by compensating snow landscapes with + 1EV (Exposure Value). In this case, the camera will expose 1 stop longer than measured.

IMAGE FORMAT

The technique in which the digital photo is stored electronically. The most well-known and used image format is JPEG, but there are dozens of other formats (TIFF, BMP, GIF,…), each with their own advantages and disadvantages.

 

ASPECT RATIO

 

The ratio between height and width of a photo. Analog cameras traditionally use the 2/3 format with a slide or negative format of 24x36mm. Most digital SLRs also adhere to a 2/3 ratio. Many digital Prosumers or compact digital cameras have a 4/3 ratio for a full-screen display on TV or computer screens.

FILE SIZE

The size of the file in which the digital photo is stored in the computer or on the various data carriers such as memory cards, CD-ROM, … This file size depends, among other things, on the number of pixels in the photo, the color depth, the compression technique used (JPEG, TIFF,…) and applied strength of this technique.

 

CROPPING

A commonly used method in photo editing software where unwanted (disturbing) parts of a photo are cut off. Also used to resize a photo or improve composition.

 

BITMAP

An image format used by Microsoft Windows without compression and therefore without loss of quality, but with the disadvantage of a very large file size. Also known as the BMP file.

 

BLOOMING

 

If an image pixel on the sensor is overexposed, this can also affect the adjacent pixels. This gives the bleed effect that sometimes becomes visible when an object is next to a strong light source or in front of a light background.

 

BOKEH

The term bokeh comes from Japanese and is used to express the aesthetic quality of blur. Bokeh is therefore a description of the out of focus area in a photo. A good bokeh or a bad bokeh means: the out of focus foreground and / or background of that photo is beautiful or not beautifully displayed. It is the shape and nature of the scattering circles that determine the quality of the bokeh.

 

BRACKETING

Taking a number of photos one after the other, whereby the exposure deviates to a greater or lesser extent from the value measured by the camera. Typically used in very difficult lighting conditions that do not guarantee that the camera will take a correct light measurement.

 

FOCAL LENGTH

The distance between the optical center of a lens and the image sensor, expressed in mm. The shorter this distance, the wider the angle of view. This is then referred to as a wide-angle lens. Longer focal lengths give smaller viewing angles, these are telephoto lenses.

 

BUFFER

Temporary storage of the image data (data) in the camera. Necessary because the image data in the camera must first be processed and then written to the storage medium at a relatively slow writing speed. This makes it possible to take a few photos in quick succession. If the buffer is full, you sometimes have to wait a few seconds before the next photo can be taken. More advanced or professional cameras have a large buffer and can take several photos per second for a longer period of time.

 

CCD

 

Charge-coupled device, a very small photosensitive cell. Millions of these cells make the CCD chip or image sensor that is the heart of many digital cameras.

CMYK

 

Abbreviation for Cyan, Magenta, Yellow and Key. With the three primary colors, most printed colors can be displayed according to the subtractive color mixing.

 

COMPACTFLASH

 

The CF memory cards are one of the most widely used type of exchangeable storage media for in the digital camera. Dimensions: 42.8 x 36.4 x 5.0mm for the CFII cards and the Microdrive. CFI is only 3.3mm thick.

 

COMPOSITION

 

Combining or arranging all parts to make a nice photo, or aiming the camera so that the (main) subject is in the most ideal position on the photo.
CONTRAST

 

The difference between the lightest shades and the darkest shades, this range is called contrast. A photo with low contrast has few pronounced dark or light tones and many even tones. A high-contrast photo has many light and dark tones with few intermediate tones.

 

COPYRIGHT

 

The property right or copyright of the photographer to protect his original work from unauthorized use.

COMPRESSION RATIO

 

A number of image formats, including the popular JPEG, allow to set the quality / compression ratio when saving the photo. A high quality / low compression ratio has little or no loss of detail, but the large file size has the disadvantage. A low quality / high compression ratio can show loss of detail and artifacts, the advantage is the small file size.

 

There are also image formats (TIFF) that apply compression without loss of quality. This is called lossless compression. However, with these methods, the image size is significantly larger than the 100% quality / 0% compression ratio of JPEG.

 

CHROMATIC ABERRATION

 

With high-contrast subjects and backlighting, a purple edge can sometimes appear (Purple fringing). Consumer cameras and cheap lenses are especially sensitive to chromatic aberration. The cause is different wavelengths of light that are not focused by the lens in exactly the same place on the image sensor. To get around this phenomenon, the lens manufacturers have designed apochromatic lenses.

 

CROPPING

 

A commonly used method in photo editing software where unwanted (disturbing) parts of a photo are cut off. Also used to resize a photo or improve composition.

 

DEPTH OF FIELD (DOF)

 

(DOF or Depth of field) The area in front of and behind the point of focus where all objects are perceived as being in focus. With the help of so-called DOF calculators, it can be calculated how large this area is, taking into account focal length, aperture, etc.

 

DESATURATION

 

Lowering the color saturation in a photo. This makes the colors less pronounced to even completely gray.

 

DIAPHRAGM

 

A number of circular blades that overlap each other and therefore determine the amount of light that passes through the lens.

 

DIGITAL ZOOM

 

A selection from the image is magnified electronically to bring the subject “closer”. A number of image pixels are artificially added, so that detail is lost. The optical zoom does not have this disadvantage.

 

DITHERING

 

Mixing technique of pixels, creating the impression that extra colors are present.

 

DPI

 

Dots Per Inch, the number of dots per inch (2.54mm). The more dots per inch (higher DPI), the better the quality. Important when printing digital photos where 300 DPI is a guide value. Pictures are displayed on screens at 72 DPI.

 

DYNAMIC RANGE

 

This is the range in brightness in which a camera can still display detail in one image, both in the darkest shadows and in the brightest parts.

 

EXIF

 

(Exchangeable Image File) In addition to the image data, this additional information is also written into the image file. The EXIF ​​contains useful information such as date and time of recording, but also a lot of technical data of the camera, for example: shutter speed, aperture, …

FILTER

 

1) apply certain effects in photo editing programs.
2) a glass element that is usually screwed onto the front of the lens and that filters out a certain type of light. The most well-known here is the UV filter, which also serves as protection against scratches on the front lens element. Some expensive lenses have the option of mounting certain filters on the camera side.

 

FIREWIRE

 

A standard used for very fast data transmission. Also known as iLink and IEEE 1394. The transfer speed between computer and peripherals is higher than the USB standard.

 

FIRMWARE

 

The software that controls the digital camera. The firmware of many cameras can be updated to allow improvements or additions to the control software.

 

FIXED FOCUS

 

A lens with a fixed focal length. Very often these provide a sharper image than the commonly used zoom lenses.

 

FLARE

 

An unwanted light reflection in the lens system that shows spots, stripes or circles in the photo. Usually happens when shooting against backlight and / or photographing light sources (sun, street lighting,…). Also sometimes creatively added to photos with photo editing software.

 

FORMAT

 

Completely erasing a memory card (or hard drive). All information is lost and the memory card can be fully used again

 

GIF

 

(Grafics Interlaced File) An image format that uses compression. However, the color palette used is too limited to be used in digital photography. As an advantage we mention the possibility of transparency and animation.

 

GRAPHIC PEN

 

Using a drawing tablet and a graphic pen, edits to the digital photo on the computer can be performed more easily than with the mouse.

 

GRAYSCALE SCALE

 

To be able to make a clear distinction (in printing) the difference between white and black is divided into 256 gray values.
A limited grayscale scale is also used with about twenty grayscale values ​​to adjust the brightness and contrast of the computer monitor

 

HIGH-KEY

 

Photography technique in which almost all shades consist of very light colors.

 

HISTOGRAM

 

A graphical representation of the different tones in the image. The graph moves horizontally from dark (left) to light (right). The number of pixels is plotted vertically. The histogram is an important tool in digital photography for checking exposure.

 

HIGHLIGHTS

 

“Highlights” are the lightest areas in a photo that are white or near-white.

 

IEEE 1394

 

A standard used for very fast data transmission. Also known as iLink and IEEE 1394. The transfer speed between computer and peripherals is higher than the USB standard.

 

ILINK

 

Communication port used by Digital Video cameras. Almost equal to Firewire (IEEE1394)

 

INTERFACE

 

A device that enables communication between two electronic devices. Also a (software) control panel on the computer to enter data.

 

INTERPOLATION

 

The technique of adding pixels when a photo is enlarged in pixel dimensions.

 

IPTC (INTERNATIONAL PRESS TELECOMMUNICATIONS COUNCIL)

 

These are data that say something about the maker, such as the name of the maker, title and location of the photo, copyright, and the like. Originally intended for news photos. See Wiki

 

ISO

 

(International Standardization Organization) Standard that indicates the light sensitivity of the camera’s image sensor. ISO 100 or ISO 200 is the most commonly used setting. The higher the ISO value used, the less light the camera requires (faster shutter speed and / or smaller aperture). However, the risk of noise generation also increases.

 

JPEG

 

(Joint Photographic Experts Group) This is the most widely used image format standard in digital photography. JPEG (pronounced jeepeg) allows an adjustable compression ratio. A compression of 1/10 to 1/20 of the original photo file is possible without visible loss of quality. See also compression ratio.

 

CALIBRATE

 

Adjusting the printer and computer screen so that the displayed and printed photos reflect reality as much as possible and each other correctly.

 

COLOR GAMUT

 

Not all colors can be accurately reproduced by the different output devices. The color gamut is all colors that can be displayed.

 

COLOR CAST

 

The color that appears to be a layer over the entire photo. Often perceived as disturbing, but can also contribute to a certain atmosphere.

CLONING

 

Technique in photo editing programs where a number of pixels are copied and “stamped” in another place, hence the name clone stamp. Cloning is mainly used to eliminate errors or disturbing elements in the photo.

 

LAYERS

 

Layers In photo editing programs, adjustments, effects or extra elements are often applied in different layers. Each layer can be edited independently of the others. The original photo is usually the bottom layer (background).

 

LANDSCAPE

 

Landscape orientation where the width of the photo is greater than its height. The way we usually hold the camera produces “landscape” oriented photos.

 

BRIGHTNESS

 

Or luminosity. Certain color brightness does not affect hue or color saturation.

 

LOSSLESS “WITHOUT LOSS”

 

A number of image formats, including the popular JPEG, allow to set the quality / compression ratio when saving the photo. A high quality / low compression ratio has little or no loss of detail, but the large file size has the disadvantage. A low quality / high compression ratio can show loss of detail and artifacts, the advantage is the small file size.

 

There are also image formats (TIFF) that apply compression without loss of quality. This is called lossless compression. However, with these methods, the image size is significantly larger than the 100% quality / 0% compression ratio of JPEG.

 

MACRO

 

Strictly speaking, macro photographs are shots where the subject is imaged 1: 1 on the image sensor. With the commonly used APS-size image sensor in digital SLR cameras, it is then possible to photograph a subject of approximately 25x16mm full-frame.

 

MACRO LENS

 

1) Additional lens for enlarging objects like a “magnifying glass” with an ordinary lens.
2) Special lens for SLR cameras to take 1: 1 photos in the macro area.

 

MASK

 

Technique used in photo editing programs to cover a part of a photo so that only this part can be edited or protected against manipulation.

 

MEMORY STICK

 

Memory card type, originally manufactured by and for Sony only. Dimensions: 50.0 x 21.5 x 2.8mm.

 

MICRODRIVE

 

Extremely small hard disk with the dimensions and capabilities of a CompactFlash memory card.

 

MIDTONES

 

Range of tones of an image approximately in the middle between highlights and shadows.

 

THUMBNAIL IMAGE

 

Small copy of an image to quickly get an idea of ​​an image without having to view it in full size. This is faster and less stressful for the computer.

 

MOIRE

 

In subjects with a regular pattern, this can show disturbing patterns. These patterns are called Moiré and can be eliminated by certain software filtering techniques.

 

NICAD

 

Nickel-Cadmium, rechargeable batteries. Less suitable for digital cameras.

 

NIMH

 

Nickel metal hydride rechargeable batteries are much better suited to digital cameras because of the greater power they can deliver. Unlike NiCad batteries, NiMH batteries do not suffer from the memory effect.

 

NOISE

 

(Noise) A type of artifact caused by electronic interference (over-amplification) in the image sensor of the digital camera, visible as random dots in the photo. Especially noticeable at higher ISO settings. Specific software is available to remove the noise somewhat.

 

OPTICAL ZOOM

 

The focal length can be adjusted by shifting a lens system in a zoom lens (zoom lens). In contrast to the digital zoom, the optical zoom has practically no loss of quality.

 

PDF

 

(Portable document format) a document format often used to distribute manuals electronically.

 

PLUG-IN

 

Many photo editing programs can also be expanded with additional filters or effects. These plug-ins do not necessarily have to come from the same software developer, but they must of course be suitable for the photo editing program you are using.

 

PIPETTE

 

A tool in photo editing programs to determine the color value of one particular pixel or group of pixels.

 

PIXEL

 

The smallest element that makes up a digital photo, a (colored) block.

 

PNG

 

(Portable Network Graphics) fairly new image format, comparable to JPEG in the result but with the possibilities of a GIF image format.

 

PORTRAIT

 

Portrait orientation where the height of the photo is greater than its width. Typical of portrait photography, hence the name. The camera is tilted 90 ° left or right.

 

PS

 

Abbreviation of the most famous photo editing program, Photoshop from Adobe.

 

RAW

 

The literally “raw” data captured by the image sensor and not yet processed by the image processor. This allows things such as color balance, sharpness, lighting, … to be better optimized for conversion to, for example, JPEG. RAW is often described as the negative film of digital photography.

 

RULE OF THREE

 

The “optimal” photo composition is built around the rule of three: in the photo a line is drawn both horizontally and vertically on one third and two thirds. The intersection points of these lines indicate the ideal position for the main subject in the photo.

 

RESAMPLING

 

Adjust the resolution of a photo or image by adding (higher resolution) or removing (lower resolution) pixels.

 

RESOLUTION

 

Displays the resolution of various output devices such as printers, monitors, cameras,… The higher the resolution, the more detail (sharpness) the image can contain.

 

RGB

 

Color model Red, Green and Blue (additive colors).

 

NOISE

 

(Noise) A type of artifact caused by electronic interference (over-amplification) in the image sensor of the digital camera, visible as random dots in the photo. Especially noticeable at higher ISO settings. Specific software is available to remove the noise somewhat.

SATURATION

 

The “brightness” of a particular color. The addition of gray produces a less saturated color. Over-saturation produces unnatural colors with sometimes a neon effect.

 

DEPTH OF FIELD

 

(DOF or Depth of field) The area in front of and behind the point of focus where all objects are perceived as being in focus. With the help of so-called DOF calculators, it can be calculated how large this area is, taking into account focal length, aperture, etc.

 

SECURE DIGITAL

 

Memory card type that is smaller than the Compact Flash (CF) cards. Dimensions: 32.0 x 24.0 x 2.1mm

 

SHUTTERLAG

 

Literally shutter lag. Time that elapses between pressing the shutter button and the image sensor actually recording the image. During that time, the camera will focus, measure exposure and color temperature. Many inexpensive compact cameras have a significant shutter lag of several seconds. Professional DSLR have a shutter lag of milliseconds. With certain cameras, you can focus in advance and measure the exposure. This requires the shutter button to be pressed halfway and it makes a noticeable difference in action photography.

 

SMARTMEDIA

 

Memory card type, larger than the CompactFlash cards but considerably thinner. Dimensions: 45.0 x 37.0 x 0.8mm

 

SOFTENING

 

Photo editing technique where the edge sharpness around objects is reduced. This gives the photo a soft, romantic atmosphere. Disturbing details such as spots on the skin in portrait photography can therefore diminish or disappear.

 

THUMBNAILS

 

See Thumbnail image

 

TIFF

 

(Tagged Image File Format) Lossless image format with lossless compression. The disadvantage is the larger file size than the more common JPEG, which can, however, result in loss of quality.

 

TOOL

 

Tools to edit the digital images electronically in photo editing software. Each “tool” has its own specific operation and application.

 

CUTTING OUT

 

See Cropping.

 

USB

 

Universal Serial Bus, communication port to connect peripherals to the computer. Unlike the old serial and parallel port, the computer does not have to be turned off. USB 2.0 is the most recent version that theoretically allows transfer rates of up to 480 MB / sec.

 

 

SHARPEN

 

(Sharpening) Software technique to increase the edge contrasts so that the digital photo appears sharper. Sharpening can be done in the camera as well as afterwards in a photo editing program. Watch out for over sharpening (oversharpening) which can cause halos around the objects in the photo.

 

SOFTEN

 

(Softening) Photo editing technique where the edge sharpness around objects is reduced. This gives the photo a soft, romantic atmosphere. Disturbing details such as spots on the skin in portrait photography can therefore diminish or disappear.

 

SATURATION

 

(Saturation) The “intensity” of a particular color. The addition of gray produces a less saturated color. Over-saturation produces unnatural colors with sometimes a neon effect.

 

VIEWFINDER

 

Camera part that allows the photographer to check that the subject is clearly in the frame. Cheap consumer cameras have a simple window through which can be viewed. More advanced cameras and DSLRs also provide information such as shutter speed and aperture in the viewfinder. Certain Prosumers have an electronic viewfinder, a small LCD screen that displays the image from the image sensor. DSLRs project the image via a (folding) mirror onto the ground glass.

 

VIGNETTING

 

The dark corners that can sometimes be seen in photos are usually due to a lens hood that is too small or the use of extra filters. As a result, the light is blocked in the corners. Some zoom lenses also suffer from vignetting in the wide-angle range, the edge of the lens is the cause.

 

WATERMARK

 

A semi-translucent symbol or text on an image, usually with the intention of indicating a copyright and preventing unauthorized copying.

 

WHITE BALANCE

 

Depending on the light source, colors will be perceived and displayed differently. Incandescent lamps, for example, give a warmer, yellow light, while fluorescent lamps give rather cool green / blue light. Time of day and degree of cloudiness also influence the colors.

 

The white balance indicates which color should be considered white so that the colors appear natural and neutral. White balance is adjustable in the camera or can be adjusted afterwards in the RAW converters.

 

 

ZOOM LENS

 

Lens with an adjustable focal length. This allows the subject to be displayed in full screen (within certain limits).

 

 

 

 

 

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