We use a lot of abbreviations in the Photo language. This might just be a good one to come back often for reference. Here they all are and the explanations:
Av or Aperture priority (Aperture value) is a setting on your camera that allows you to adjust the aperture value (otherwise known as the f-number or f-stop) while the camera automatically selects a shutter speed to produce an image with the correct exposure.
As you adjust the aperture for different photographic effects, the camera’s internal light meter measures the lighting conditions of the scene and adjusts the shutter speed accordingly.
AF = Auto Focus. The AF feature automatically adjusts the camera lens to focus on a subject, creating a sharp image.
There are several types of AF focus modes. Single focus, known as AF-S (Nikon) or One Shot AF (Canon) will cause the camera to lock focus on a subject and the camera won’t re-focus while you keep the shutter actuator depressed half way. Continuous or tracking focus – AF-C (Nikon) or AI Servo (Canon) on the other hand, continuously readjusts the focus if you keep the shutter button half-depressed. This maintains focus on moving subjects. Some cameras also have a mode called AF-A (Nikon) or AI Focus AF (Canon) that switches between the two modes automatically.
AWB = Auto White Balance. Light is different under different conditions. AWB or Automatic White Balance works in-camera to measure the white balance (WB) of a scene and remove any color casts that may impede on a photograph. In short, it tries to automatically analyze and color correct your scene. It works fairly well in most cases but can be tricked.
B = Bulb. a mode designed for longer exposures like those often seen in time-lapse photography. In Bulb mode, when you depress the shutter button, the shutter will remain open until the button is pressed again (or until it is released, depending on your camera).
This mode is usually used in conjunction with a tripod and a remote shutter release and is necessary to achieve exposures longer than 30 seconds (the maximum exposure time on most cameras).
CMYK = stands for cyan, magenta, yellow and black. Black is referred to as K which is shorthand for the key plate . a printing tool which makes the artistic detail of a picture in black ink. CMYK is the color space used for most color reproduction printers (magazines, posters, business cards, etc.). This four-color mode utilizes each color in set amounts to create a color print. It is a subtractive process, so each additional color means more light is absorbed to create colors.
Because RGB (the color space in which your camera records an image) provides a larger range of colors available on the digital screen, a printed image will be inconsistent with the image you see when you press “print”. Converting an image to CMYK in Photoshop or Illustrator before printing will produce an image on the screen that is much closer to the printed product, allowing you to print an image accurately.
DOF = DEPTH OF FIELD. is the zone of focus in a photograph. Depth of field is affected by the aperture. A large aperture creates a shallow depth of field with a small amount of the image will be in focus. A small aperture creates a large depth of field with more in focus. Depth of field is also defined by lens focal length and the distance from the subject to the camera.
DPI = Dots per inch. dots per inch is often used interchangeably with PPI or pixels per inch. Technically, DPI measures the number of dots that can be printed in a line within the span of one inch. PPI also measures the number of dots in a line within the span of an inch but on a computer screen instead. Printers and screens with higher DPI or PPI values are clearer and more detailed.
You need to know the DPI of your printer or lab to correctly size your images for printing.
DSLR= DIGITAL SINGLE LENS REFLEX. A DSLR camera has a mirror that reflects the light coming in from the lens and directs it through a prism or set of mirrors to the viewfinder. This arrangement allows you to see what you are shooting by looking through the viewfinder. When the shutter button is depressed, the mirror flips up and allows the light coming through the lens to reach the camera sensor.
F-stop or f-number: The f-stop or f-number is a term that indicates the size of the aperture opening on your lens. Every aperture is expressed as an f-stop or f-number, like f/8 or f/2.8.
IS = Image stabilizer. IS stands for Image Stabilization. This technology goes under several names; Vibration Reduction, SR, VR, and VC are a few. Image stabilization is a feature in your lens (not all lenses have it!) that enables you to photograph sharper images when shooting handheld at lower shutter speeds, in dark conditions, at longer focal lengths.
ISO . ISO stands for International Standards Organization. In film photography, ISO (or formerly ASA) was an indication of how sensitive a roll of film was to light. In digital photography, ISO measures the relative sensitivity of the camera sensor. This value can be adjusted in-camera.
The higher the number, the more light the sensor can capture. However, the greater the sensitivity of the film or sensor, the grainier the image will be (in digital photography it’s called noise).
Editor’s Note: Before you jump up and down and add a comment below about the fact that the sensitivity of the camera sensor does not actually change, let’s agree to keep it simple for the purpose of this article and these definitions. No, it isn’t that simple, but people new to photography need to take baby steps in understanding these terms, so please accept that we’ve simplified it here.
JPEG. JPEG (sometimes shortened to JPG) is an image file format. It stands for “Joint Photographic Experts Group” – the name of the group that created the format. It’s one of the most common image formats saved by digital cameras, the other being RAW.
JPEG files are lossy which means that images in this file format are compressed. Lossy formats are smaller and easier to handle, but they suffer from a loss of quality.
M = Manual mode. Manual Mode is a shooting mode on your camera that when activated, means that you have complete control over every setting on your camera. This includes the aperture, shutter speed, ISO, white balance, metering mode, and more.
Note: Manual Mode and Manual Focus are NOT the same thing and are not exclusive of one another. Meaning you can shoot in Manual Mode using Autofocus, or in an Automatic mode using Manual Focus.
M4/3 : M4/3 is short for Micro Four Thirds and it is also known as MFT. Developed by Olympus and Panasonic in 2008, the M4/3 is a mirrorless interchangeable lens system for digital cameras and lenses. This mirrorless system means that the camera does not have an optical viewfinder system like conventional SLR/DSLR cameras, but an electronic viewfinder (EVF) instead. This system is simpler, lighter and allows for smaller cameras than DSLRs.
P = Program mode. This shooting mode has the camera adjust aperture and shutter speed automatically, while allowing you to adjust other settings like ISO, flash, white balance and focusing functions.
RGB = RED, GREEN, BLUE. Based on the human perception of colors, RGB stands for Red, Green, and Blue. RGB is an additive color space designed for viewing imagery on digital displays (see CMYK above).
S = Shutter Priority mode.
Shutter Priority Mode (also known as SP or TV for Time Value) is a setting that allows you to select the shutter speed while the camera automatically adjusts the aperture for proper exposure. As you adjust the shutter speed the camera’s internal light meter measures the lighting conditions of the scene you’re shooting and adjusts the aperture accordingly.
This mode is best used for shooting fast moving objects or when you want to blur or freeze a moving subject.
SLR = SINGLE LENS REFLEX. SLR or “single lens reflex” refers to a non-digital camera with single-lens reflex capabilities (see DSLR).
TIFF. Short for Tagged Image File Format, TIFF is a file format for digital images that does not lose color and detail in the way that lossy compression formats such as JPEG files do. This type of file format is described as lossless.
TTL = THROUGH THE LENS. Through the Lens and refers to an automatic flash metering system. The flash fires a short burst prior to the actual exposure, the camera reads the amount of light coming through the lens, and sets the power of the flash according to the selected aperture. This mode is most often used with the flash on the camera.
USM = ULTRA SONIC MOTOR. a type of autofocus motor in lenses trademarked by Canon. Equivalent systems include Nikon’s SWM (Silent Wave Motor), Sigma’s HSM (Hyper-Sonic Motor) and Olympus’ SWD (Supersonic Wave Drive Motor). They are designed to have the lens’s autofocus work as silently as possible.
WB = WHITE BALANCE. the act of balancing the color cast found in different lighting conditions for an accurate image (see AWB). White Balance can be set in-camera and adjusted in post-processing if you have shot in RAW format.
That seems complete as for now. You know that will change as technology is added into these cameras and other things. So, this will be updated as time goes on for sure. If I have missed any that you think are important, please add them in the comments below.
***** This article written by Megan Kennedy for the Digital Photography School.