A quick, plain-language reference to the terms used across New England Light. No jargon for its own sake — just what each word means and why it matters to a picture.
Exposure
- Aperture
- The adjustable opening in the lens, measured in f-numbers (f/2.8, f/8, f/16). A wide aperture (small f-number) lets in more light and gives a shallow depth of field; a narrow aperture (large f-number) gives more front-to-back sharpness.
- Shutter speed
- How long the sensor or film is exposed to light, measured in fractions of a second. Fast speeds freeze motion; slow speeds blur it — the silk of a long-exposure waterfall, or camera shake if handheld too long.
- ISO
- The sensitivity of the sensor or film to light. Low ISO gives the cleanest image; high ISO lets you shoot in dim conditions at the cost of more visible grain or noise.
- Exposure triangle
- The interdependence of aperture, shutter speed and ISO. Change one and you must usually adjust another to keep the same brightness.
- Dynamic range
- The span of brightness, from deepest shadow to brightest highlight, that a camera can record in one frame. Scenes exceeding it force a choice about what to keep.
Optics and focus
- Focal length
- The lens's angle of view, in millimetres. Short focal lengths (wide-angle) take in more; long focal lengths (telephoto) magnify and compress. Around 50mm on a full frame approximates natural human perspective.
- Depth of field
- How much of the scene, front to back, is acceptably sharp. Controlled mainly by aperture, focal length and distance.
- Prime lens
- A lens of a single fixed focal length. Primes are often sharper and brighter than zooms and encourage a photographer to move rather than zoom.
- Bokeh
- The visual quality of the out-of-focus areas of an image, especially background highlights rendered as soft discs.
Light
- Golden hour
- The period shortly after sunrise and before sunset when sunlight is low, warm and soft — prized for landscapes and portraits.
- Blue hour
- The twilight period before sunrise and after sunset when light is cool, even and gentle.
- Hard and soft light
- Hard light (small or direct source) casts sharp-edged shadows; soft light (large or diffused source) casts gradual ones. Soft light flatters; hard light dramatises.
- Backlight
- Light coming from behind the subject toward the camera, used for rim light, silhouette and atmosphere.
Craft and workflow
- Decisive moment
- The instant when the elements of a scene align into their most expressive arrangement — a phrase associated with documentary photography.
- Rule of thirds
- A compositional guide placing key elements a third of the way into the frame rather than dead centre.
- Exposing to the right
- Biasing a digital exposure toward the brighter end (without clipping highlights) to capture the cleanest possible shadow detail.
- Contact sheet
- A single sheet showing small versions of every frame from a roll or shoot, used to review and select the strongest images.
- RAW
- A minimally processed image file preserving the maximum data from the sensor, giving the most latitude when editing exposure and colour.
Camera and file controls
- White balance
- The setting that interprets the colour of light so neutral objects appear neutral. Daylight, shade and artificial light may call for different balances.
- Metering
- The camera's estimate of scene brightness. Evaluative metering reads most of the frame; spot metering reads one small chosen area.
- Exposure compensation
- A control that tells an automatic mode to make the frame brighter or darker than the meter recommends, usually measured in stops.
- Histogram
- A graph of image tones, from shadows at the left to highlights at the right. It reveals clipping that can be difficult to judge on a bright screen.
For these terms in practice, read the field guide to light and composition. A deeper history of the medium's vocabulary is maintained by encyclopaedic sources such as Encyclopaedia Britannica.