Reference
Film photography glossary
From aperture to the Zone System: a quick reference to the core language of film photography, with links to the relevant tools and dossiers.
- Aperture
- The lens opening, measured in f-stops. Smaller numbers mean a wider opening and less depth of field. Related →
- ASA / ISO
- The film's sensitivity to light. Higher ISO means a faster film with more grain. Related →
- Bokeh
- The character of out-of-focus areas, shaped by the lens and aperture blades.
- Box speed
- The ISO printed on the film box, and the reference for metering.
- Bracketing
- Shooting several frames at different exposures to guarantee a usable result.
- C-41
- The standard colour-negative development process.
- Circle of confusion
- The largest blur circle that still looks sharp; the basis of depth-of-field maths. Related →
- CLA
- Clean, lubricate and adjust: a routine service for mechanical cameras.
- Contrast
- The range between the darkest and brightest tones in a scene or image.
- Crop factor
- The ratio that converts a lens's field of view between formats.
- Cross-processing
- Developing one film type in another's chemistry (E-6 in C-41, or vice versa) for extreme colour shifts. Related →
- Density
- How dark a negative is after development; more exposure or development means more density.
- Depth of field
- The zone in front of and behind the focus point that appears acceptably sharp. Related →
- Developer
- The chemical that converts exposed silver halide into visible metallic silver.
- Dodging and burning
- Selectively lightening (dodging) or darkening (burning) parts of a print or scan.
- Dynamic range
- The range of brightness a film can record from shadows to highlights.
- E-6
- The standard development process for colour slide (reversal) film.
- Emulsion
- The light-sensitive gelatin layer coated on film base.
- EV
- Exposure value: a single number describing a combination of aperture and shutter at a given ISO. Related →
- Exposure triangle
- The relationship between ISO, aperture and shutter speed. Related →
- Fixer
- The chemical that removes unexposed silver halide so the image becomes permanent.
- Grain
- The visible texture of silver halide crystals in a developed image. Related →
- Halation
- A red or orange glow around bright highlights, caused by light reflecting off the film base.
- Half-frame
- A 35mm format that exposes two images per standard frame, halving cost per shot. Related →
- Hyperfocal distance
- The focus distance that puts everything from half that distance to infinity in acceptable focus. Related →
- Latitude
- How much a film can be over- or under-exposed and still usable. Related →
- Light meter
- A device or app that reads the light and suggests aperture and shutter combinations.
- Medium format
- Film formats larger than 35mm, such as 6x4.5, 6x6 and 6x7. Related →
- Negative
- Film in which tones are inverted; printed or scanned to produce a positive image.
- Push / pull
- Rating a film above or below box speed and adjusting development to match. Related →
- Rangefinder
- A camera that focuses using a split or superimposed image rather than through the lens. Related →
- Reciprocity failure
- The loss of effective film speed at very long or very short exposures, requiring compensation. Related →
- Remjet
- A black anti-halation backing on cinema film that must be removed during processing.
- SLR
- Single-lens reflex: a camera that views through the taking lens via a mirror. Related →
- Stop
- A doubling or halving of exposure, whether by aperture, shutter or ISO. Related →
- Stop bath
- A dilute acid bath that halts development before fixing.
- TLR
- Twin-lens reflex: a camera with separate viewing and taking lenses, usually 6x6. Related →
- Tungsten-balanced
- Film balanced for artificial (tungsten) light, which looks blue in daylight without a filter. Related →
- Zone System
- Ansel Adams's method of placing tones into eleven zones to control exposure and development.