A

Alignment

Positioning of text or graphic on a page.

Alley

The blank space between two columns of text.

Aliasing:

Enlarging a bitmap image can produce aliasing (jagged edges), making the squares that it is consists of, visible. This happens especially for curves and edges which are harder to replicate with squares. The smaller a bitmap image is or the more zoomed out, the cleaner do the edges appear.

Anti-aliasing

The process of smoothing out jagged edges, making an image look less blurry.

Aperture

The camera has two settings that control light, and they work very similar to the human eye, one is the shutter and the other is the aperture.

Before light reaches film, it must pass through an opening called an "Aperture". The aperture is like a pupil (which controls light). You can control the aperture (the size of the opening in the camera lens) at the moment a photo is taken by setting the "Aperture Opening", also known as an F-Stop. It  closes up to restrict light, and opening up to let it through. It is measured in fractions. Larger F-stop numbers mean smaller openings and smaller numbers mean larger openings and larger openings mean more light.

Application

A computer program, for example Photoshop.

B

Bit depth

Bit depth or colour depth refers to the number of bits used to store an image’s individual pixel information.

1-bit   (21)  = 2 colours - black-and-white, 2-bit   (22)  = 4 colours - grayscale

8-bit   (28)  = 256 colours - Web graphics, 16-bit (216) = 32,768 colours - High Colour

24-bit (224) = 16.7 millions of colours or Truecolour.

Bitmap images

Composed of pixels in a grid or raster. Because of their fixed resolution, bitmap images are also called fixed resolution images. When resizing, distortion and jagged edges can occur. .gif, .jpg and .tiff are bitmap formats.

Bleed

Any text or graphic element touching the edge of a page is called a bleed.

Blurring

Blurring can give a very interesting look to an image. There are a number of blur type tools available for image editing. E.g. You can highlight the background of an image by using a tool called Gaussian Blur. This is a specific type of blurring routine designed to imitate the blurring that happens in traditional photography, making the subject stand out against the background. Generally, a small blurring which leaves the background out of focus, but still recognisable is better than too much.

Panning in photography, creates a blurred effect in the background when photographing moving objects. If you focus on a moving car, keeping the camera pointed at the car as it goes by, it should be in focus and the crowd in the background would be blurred. This is Motion blur, or sometimes Radial blur. If you use Radial instead of Gaussian blur, the car can appear  to be racing past the background.

Brightness

The amount of light in the picture. The longer the lens is open and the wider the lens aperture, the brighter the photo. Changing the brightness setting will adjust the colours of the pictures as if the photo was taken with a wider or narrower aperture. However, the increased brightness can cause the picture to look washed out and this is where contrast comes in handy. Brightness and contrast are generally used together when image editing.

Burning

Darkens a chosen part of a picture by adding extra exposure.

C

Cloning

To copy one part of the image into another area, or into another picture. Useful when there is an item in the photo that needs to be removed by copying an area and placing it on top of the unwanted area. E.g. remove a rubbish bin from a picture by cloning the wall next to it and placing the cloned area on top of the rubbish bin. Useful also if you have two photos that each have elements you are not happy with. E.g. Two photos and in one a child is yawning and in the other, another child is looking away. You can clone the child not yawning in the second photo and add it to the photo first photo so that both children are looking at the camera and smiling.

CMYK

An acronym for Cyan, Magenta, Yellow, Key (which is Black), which are the four colours used in the standard printing process. It's also a colour mode in photo editing applications.

Colour

When photographing, the human eye can see an almost infinite number of shades that a digital camera can't. It has to reduce the variety of shades it sees into a collection of dots of solid colour as a pixel colour cannot be divided. The camera has to analyse where two colours meet and then guess the intended colour of the dot in between. Usually it is an average shade between those two colours. This can fool the human eye, which sees the averaging as fuzziness and can look quite acceptable.

Compositing

Combining visual elements from different image sources into single images, often to create the illusion that all they are parts of the same scene. In the digital method of compositing, software commands designate a narrowly defined colour as the part of an image to be replaced. Then every pixel within the designated colour range is replaced by the software with a pixel from another image, aligned to appear as part of the original.

Contrast

Contrast is the range of dark and light in the picture (the spectrum between the darkest and the brightest regions of the photo). Changing the contrast will make the bright elements brighter and the dark ones darker. Adjusting the contract will counter balance the changes made by adjusting the brightness. Brightness and contrast are generally used together when image editing.

Cropping

To cut out part of a picture, usually the edge. You might crop to focus attention on the real subject, or to remove distracting elements within the picture. Also known as trimming.

You can crop a high resolution image to an area that you want to keep. E.g. a photo of a baby being held in the arms of a parent. You crop the photo so only the feet of the baby held by the parent is shown. If the resolution is high enough you can resize the cropped image to a standard photo size. The result being a quality picture of a babies feet. This can be a rather endearing image.

D

Digital resolution

A measure for the number of pixels (or dots) in an image or printer. Applications differ, some use  pixels per inch (PPI)to measure image resolution and some use dots per inch (DPI) to measure printer resolution. The more pixels or blots of ink, the sharper the image will be.

Dithering

The incorrect interpretation of colour . E.g. if the bit depth varies from image to monitor. A monitor that can only replicate 256 colours will fall short when displaying an image that was made with a millions-of-colours setting. The image might look pixelated, grainy or dotty.

DVD

When storing digital pictures, a DVD looks similar to a CD but can hold 4.7 GB of data.

Dodging

Gives the impression of less exposure in parts of a photo and so makes the photo lighter.

Download

Downloading is the opposite of uploading. Downloading means to get a copy of data from another location, such as the Internet and from a camera.

DPI

Most photo printers and monitors measure their resolution in Dots Per Inch, or DPI. The higher the number, the higher the resolution and the better the picture.

E

Embossing

Creating a three-dimensional look. Can be used with text and images when digital editing.

EXIF

Exchangeable Image Format. Most digital images have two parts. The first is the image, usually stored as a JPG image. The second is the EXIF data, which often includes all of the photographer's information such as the date and time the photograph was taken and the shutter speed and aperture setting.

Exposure

Exposure is controlled by the size of the lens opening, the film speed, and the duration the lens remains open when taking a photograph. The combination of shutter and aperture (f-stop) settings  can dramatically alter the appearance of the finished photograph. Shutter and f-stop are each measured in stops, so take away 2 stops from the aperture, and give 2 stops back with the shutter to keep the balance and you end up with the same level of exposure.

In photo editing, we can adjust exposure further, with brightness and contrast controls.

F

Feathering

The feathering editing technique helps to break up the outline of a selection so that the edge is less sharp. This is a useful tool in digital editing.

Flip

Flipping an image in editing terms is the same as reflecting it in a mirror. Can be useful when wanting to change an image, for example flip a part of a photo to show a person looking at an object rather than looking away from it. Also used to create symmetrical patterns.

G

Grayscale

A spectrum of grey shades from black to white. A grayscale picture is the digital equivalent of a black and white photo.

H

Highlights

The Highlights are the whitest part of a picture. They tend to be a very small percentage of the picture, because it's very easy to lose details in highlights.

Histogram

A chart that graphs all of the tones in a photo.  If you want to count how many dots of each colour there are in a given picture and see how those dots compare against each other. A Histogram can show if the photo was washed out or too dark before we print it. Many digital cameras will generate a histogram at the push of a button, for either the picture you've taken or the one you're about to take. Most photo editing programs can portray a Histogram of an image.

A dark photo will have the bulk of the data on the far left side of the chart, while a "daylight" photo will be somewhere in the middle. The chart could show a single hump, or a series of spikes; it could be very tight, only a fraction of the histogram, or it could spread from edge to edge.

If the data is up against the edge this could be a bad picture. The far left edge is pure black, and the far right is pure white. If there's a large amount of absolute black or white in the picture, then some detail has probably been lost.

I

Image File Format

The format of an image file determines amongst other things, the size of the file and the overall image quality. When dealing with photographs, it is important to use the best file format for your requirements. Common image file formats are JPG, GIF, TIFF, and PNG. Click for more information.

ISO

International Organization for Standardization, which refers to the film's sensitivity to light. Light sensitive crystals either react and are developed, or do not, and the speed at which they react is the same for any given film. It is a function of size, but is described in terms of speed. The increase in speed is the result of larger crystals as they are able to react more to light than smaller ones, producing more image in the same length of fixed time. These numbers, mean that a particular film can gather light very fast or very slowly.

The larger the number, the more sensitive the film. ISO 100 needs a lot of light, like outdoors on a sunny day. ISO 1600 doesn't need much light. However, higher ISO also means more grain in the film. Digital images use the ISO scale to measure the sensitivity of a camera sensor. At higher ISO settings, more "noise" is added to digital images. In film and digital photography, as ISO goes up, quality goes down.

Doubling the number 400 vs 200, means the film is twice as "fast".

Examples:

ISO100 absorbs light slowly, so it is good for using when there is a good daylight or when you have bright light or flashes and strobes.

ISO400 is for poor light, indoors or at dusk or twilight.

ISO1600 or ISO3200 can gather light very fast, so can be used at night, or with very low lighting levels but will give grainier/noisier photos than lower ISO films.

Use a fast shutter speed to freeze an action when you are photographing sports, action or fast moving wildlife.

J

Jpeg

A type of image format.  See file formats.

L

Landscape

Landscape, like portrait has two meanings. Landscape is the term for a picture of wide open spaces, like hills or a sunset. It is also a reference to the alignment of a picture or page. Pictures or pages that are oriented horizontally (with the narrow sides upright) are  Landscape.

Lasso

This image editing tool is used to separate obvious lines for selection. You can use the Lasso selection tool to select the area to burn, dodge, brighten, blur etc. so only the selected area or inverse selected area is edited.

Layers

Layers are like sheets of tracing paper laid over the top of your image. Graphic designers use layers to separate out elements of their project, so that they can work on individual pieces without damaging others. Adjustment layers are layers that show the results of whatever filter or function is attached to that layer. They allow you to change and adjust your photo in many different ways without changing the original photo. These changes are put into layers so that you can accept or delete the ones that you want to use or remove. Layers are stacked on top of each other so that you can see what effect each layer brings to the picture and take away what does not work. For example, you can use a layer to overlay a colour to change the whole picture to shades of that colour. You can use layers to put different photos together to end up as one photo.

Light

Light of various temperatures is associated with a temperature in Kelvin. E.g. a camera flash is about 5600 Kelvin, a light bulb could be about 3400 K and candles 1500 Kelvin.

Digital cameras usually require a lot more light than film cameras. Try experimenting by taking photographs of the moon for example, with a digital camera you may well end up with a hazy dot.

When photographing people, indoor photos may not come out as well as outdoor shots, unless lots of light is directed on the person. Its good to experiment. Digital camera photos are known for producing grainy images in poor lighting, so try not to have your subjects stand with their backs to the direction of the sun. Always try to use the light to its best advantage.

Lorem ipsum

Dummy text that is inserted as page filler in a page layout. It mimics word and sentence flow. It is used when creating a layout for a new document where the real text is unavailable or will interfere with the layout design process. By using the Lorem ipsum dummy text, the focus is on the design instead of being distracted by reading the text.

M

Media

The term for storage. Compact disks, memory cards and sticks and DVDs are storage media.

Megapixel

One million pixels or dots. Megapixels are the standard for measuring the power of a digital camera. The more megapixels the better the image might be.

Megapixels are a guide to how large a good quality print you can expect. Pixels are dots. If you enlarge the picture enough, the individual dots become obvious. The more pixels, the larger you can expand the picture before the dots become visible.

E.g. a 4 megapixel image can be printed at about 5x7, a 5 megapixel image would be suitable for an 8X10 print, without making the pixels so large it ruins the picture.

You can print a large megapixel image in a smaller size but it does not work in reverse. For example a three megapixel image might look good on a computer monitor and could be printed at 3x5, but the dots will be too obvious if the picture is blown up into a large image.

The same applies to photo editing programs, which cannot easily enlarge a small megapixel image, as you cannot make the dots bigger.

The program has to Interpolate, to guess what colour the new pixels have to be. There are programs specifically designed for enlarging digital images.

The standard of the lens also plays a part in the quality of the image and is a much more important feature than the pixels. A poorly built lens takes the power out of the camera, because a fuzzy picture whatever the number of megapixels is still fuzzy.

When purchasing a new camera, attention should be paid to the quality of the lens as well as the number of megapixels. Also consider the optical zoom size (rather than digital zoom).

O

Opacity

When something is Opaque, the more opaque it is the less see through it is.

P

Panning

Panning the camera involves following a moving subject while snapping the picture. Done properly, the subject will be sharp and the background behind it will be blurry. This can be imitated when using a radial blur on the background when editing.

Photo-montage

The process and result of making a composite photo by cutting and joining a number of photographs. The composite picture was sometimes photographed so that the final image is converted back into a seamless photographic print. A similar method when image-editing software is known as "compositing”.

Pixel

Pixel is picture element and refers to the individual image dots you can see on the screen. All digital pictures are made up of pixels, and counting them is a measure of the image (pixels per inch (PPI), in print, dots per inch (DPI), and camera power, millions of pixels (megapixels).

Pixelated

A grainy look of images, especially when enlarged, where on can see the individual dots of colour. Usually to be avoided.

PDF

Portable document format. A file format developed by Adobe that has become the industry standard for sharing files. To be able to read PDF files you need to have a copy of the PDF reader program on the computer, which can be obtained at  http://get.adobe.com/uk/reader/otherversions/.

Portrait

Portrait like landscape has two meanings. Portrait is a term for a picture of a person. It is also a reference to the alignment of a picture or page. Pictures or pages that are orientated vertically (with the long sides upright) are known as Portrait.

R

Red Eye

Modern digital image editing programs can fix red-eye. Red Eye is the reflection of the camera flash off the back of the subject's eyes. In dim light the subject's pupils are wide open, so the light from the flash can travel all the way to the far back of the eye. This then, bounces off the retina, picking up the reddish (red eye) tint along the way, and returns to the camera.

Some cameras have an added red-eye reduction mode, where there are two flashes for each picture. The first one is a pre-flash, half a second before the real one. This is to trigger the pupils to shrink, reducing the chance for red-eye. It does not eliminate red-eye, it just tries to lessen it.

Resolution

The image resolution is the number of pixels, or dots, in a picture.

RGB

Stands for Red, Green, Blue. It is the standard colour format for digital images. Each of the colours  is given an amount between 0 and 255, and the blend of the three colours produces all of the other colours. E.g. 0,0,0, creates white and 255, 255, 255 creates black. This mode is used for Web images. See also CMYK.

S

Saturation

Saturation is a measure of the richness of the colours in a photo. When a picture is desaturated, all of the colour information has been removed, and what's left is a grayscale or black and white picture.

It is also used for changing the character of a photograph by emphasising certain colours.

Sharpening

Sharpness describes the focus and clarity of a picture. Sharpening the picture when photo editing is intended to correct the guesswork that the camera had to do. The program analyses the borders between colours, and attempts to make them stand out again. A lot of digital photos could benefit from this. Care should be taken not to over sharpen, otherwise, when you zoom in very close, you can see where the program put a lighter area of colour between the two shades, to make the border stand out. If the image is too sharp these light lines will become too obvious and give an unwanted halo effect upon the image.

Shutter Speed

The camera has two settings that control light, and they work very similar to the human eye, one is the shutter and the other is the aperture.

The Shutter speed determines how long the shutter stays open. The shutter blocks all light from exposing the film until you press the button. Then it quickly opens and closes, giving the film a brief flash of light. You control the length of time the shutter remains open by setting the shutter speed. The longer the shutter speed the more light, the shorter the shutter speed the less light. Shutter speed does not control motion. The recorded images of moving objects will be more or less sharp depending on the shutter speed and the speed of the objects across the field of view

Slow shutter speed keeps the shutter curtain open for longer periods of time, e.g. when you shoot at night or in fading low light.

Fast shutter speeds opens and closes the shutter in a fraction of a second and are used to capture action or when scene you are trying to shoot is well lit.

Straighten

Photo editing allows for straightening photos. This is done by drawing a line on the item that should be straight (a side of a door for example). The program then rotates the photo to make that line vertical. Some un-straightened photos can be effective if the photo was taken at an interesting angle. You can even create that angle using the straightening tool, by giving it a false vertical line.

T

Templates

A design template be used repeatedly and can be anything from a simple page outline to an almost finished layout.

Text frames

Areas that contain text on a page.

Text layout

Text composition is the design of text on the page. This includes font size, text placement, alignment and appearance and character spacing.

Thumbnail

A small version of a larger picture. Many programs use thumbnails to index a picture collection.

A contact sheet is a page of thumbnail pictures.

U

Unsharp Mask

This photo editing tool actually does the opposite of what the name seems to imply. It actually sharpens the image. Multiple sharpening steps can make a picture look terrible, so it should only be done once, when all the other edits have been carried out.

Uploading

The opposite of downloading. Uploading is sending a file from your computer to another system, through a cable or over the Internet.

W

Web design

The creation of pages that viewers can see on the web.

White Balance

Cameras have a variety of programmed settings. White Balance is an automatic setting to account for adjustments in light sources. Some artificial lights "tint" the colours that they project. The camera's white balance setting should be used to balance this back to a more accurate colour.

The camera recognises that if the setting is for fluorescent bulb, then the white is going to look more purple. It compensates by finding an example in the frame that it assumes is meant to be white and it then adjusts the spectrum accordingly. Hopefully, then the picture will turn out with the right colours. It is usually fine to let the camera decide the white balance automatically, unless your picture has wide areas of just one colour. A sunset can have a rich golden yellow light.

If the camera's white balance was incorrect, then the photo editor can change the colour scale. The program will use an area that was supposed to be white or black as the starting point, and the application will re-map every other colour in the picture accordingly.

WYSIWYG

What-you-see-is-what-you-get. This refers to web design and desktop publishing that allows what is visible on screen during the creation process to be the end result.

Z

Zooming

Zooming in and out. Allows you to zoom out to see the whole area or zoom in to focus on a much smaller area. Very useful when editing digital images.