Digital Photography Glossary
Photography Glossary - A
Understand the terminology of digital photography, digital printing and digital imaging so that you will become a better photographer. Photographic terms such as Ambient Light, Aperture, Aperture Priority, Autofocus, Autexposure Bracketin, and more.
AI Focus AF
This is a hybrid auto-focus mode available on the higher end Canon EOS digital cameras (i.e. 5D, 1000D, etc.), where the camera automatically switches between One Shot mode and AI Servo mode (AI refers to “artificial intelligence”). AI Focus AF initially begins in One Shot Mode, and when the camera's AF sensor detects that the main object is moving, the camera rapidly switches to AI Servo mode to maintain crisp and clean focus.
AI Servo AF
AI Servo AF is an auto-focus mode that continuously focuses on a subject –one that is moving -- until you find that decisive moment to snap the picture. The AI in the title refers to “artificial intelligence” and the camera's computer makes a prediction on where the subject will be.
AE Lock is a camera setting that lets you lock your automatic exposure, so you keep the same combination of f-stop and shutter speed, when your camera is in one of semi- or full automatic exposure modes. In addition, AE Lock holds the exposure settings over a series of pictures, such that the camera isn't recalculating the exposure after each press of the shutter release.
Ambient light is the unadulterated and unassisted light in any environment. It may be the sunlight, it maybe the lamps in your apartment, plus the sunlight, it might be the light from neon signs, street lights and moonlight at night.
Angle of Incidence
Angle of incidence is a technical term that describes the angle of light as it strikes a surface. Understanding the angle of incidence is important when setting reflectors and determining what the angle of reflection is going to be, as they are one and the same.
Angle of View
The Angle of View is the width of a subject as seen through a lens. It is typically stated in relation to the diagonal length of an image. A larger angle of view (on wide angle lenses) shows the viewer more things and space, but they appear smaller. Conversely, a small angle of view (on telephoto lenses) shows the viewer less things and space, but they appear larger.
The aperture is the opening in the lens through which the light travels to hit the image sensor (or film frame). The aperture controls the amount of light that hits the image sensor and determines that conical angle of light rays that come to a focus point on the image plane.
Click here to learn more: Focusing Basics - Aperture and Depth of Field
Aperture Priority is a semi-automatic setting for your camera, in which you manually set the aperture (or f-stop) and the camera's computer determines exposure by selecting the shutter speed that works best for the selected f-stop. Aperture Priority mode gives you greater control over an image's depth of field in an automatic mode.
The Aperture Ring is the rotating ring on the lens barrel that controls the selection of f-stops. The aperture ring is where you will find the minimum and maximum f-stop settings for a given lens, and the critical focus mark.
Like the name denotes, Artificial Light is any light that comes from a man-made light source, so it can come from dedicated photo floods, everyday household lamps, overhead fluorescent lights. Artificial light is usually tungsten-balanced, but special photographic lamps are available to produce the cooler, blue light of sunlight.
Autoexposure Bracketing - allows for the camera to automatically take a series of photos (usually three, but on some camera models up to seven exposures), each at incrementally different exposures. Such that the first image taken is at the exposure you originally set, then the second is one stop underexposed and the last image is one stop overexposed.
Click here to learn more: Undestanding Exposure - ISO, Aperture and Shutter Speed Explained
Autofocus is a feature in which the computer-controlled servos automatically focus the lens on your subject of choice as you depress the shutter release half-way. Autofocus on today's digital cameras is so advanced that it can predict the direction an object is moving, work in very low-light situations and compensate for camera shake, so that focus remains razor-sharp in the vast majority of circumstances and situations that you'll find yourself in.
Automatic Exposure AE
Automatic Exposure is a modern camera feature in which the image sensor detects the ambient and reflective light entering your lens and selects an appropriate aperture setting and shutter speed to give you an effective exposure.
Any naturally occurring light which illuminates a scene that isn't provided by the photographer, e.g. the sun, the moon, building light, or other light source.
An automatic exposure metering mode in the camera's TTL (Through-The-Lens) metering system that measures the entire scene and averages the exposures to give provide a uniform, neutral exposure value.
Click here to learn more: Learn all about Exposure Metering Modes