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Safelight

An enclosed darkroom lamp fitted with a filter to screen out light rays to which film and paper are sensitive. Light source consisting of housing, lamp and screen of a colour that will not affect the photographic material in use. Safelight screens are available in various colours and sizes for specific applications.

Saturation

An attribute of perceived color, or the percentage of hue in a color. Saturated colors are called vivid, strong, or deep. Desaturated colors are called dull, weak, or washed out.

Scale.

Focusing method consisting of set of marks to indicate distances at which a lens is focused. May be engraved around the lens barrel, on the focusing control or on the camera body.

Screen.

In a camera. the surface upon which the lens projects an image for viewfinding and, usually, focusing purposes. In SLR cameras. almost universally a fresnel screen with a fine-ground surface. Often incorporates a microprism or split-image rangefinder.

SDC System Developing Companies

Kodak and four other photo industry leaders who jointly developed the Advanced Photo System standards.

Selective Focus

Choosing a lens opening that produces a shallow depth of field. Usually this is used to isolate a subject by causing most other elements in the scene to be blurred.

Selenium.

Light-sensitive substance which, when used in a barrier-layer construction, generates electrical current when exposed to light. Used in exposure meters. Needs no external power supply.

Self-timer.

Mechanism delaying the opening of the shutter for some seconds after the release has been operated. Also known as delayed action.

Semi-automatic iris.

Diaphragm mechanism which closes down to the taking aperture when the shutter is released, but must be manually re-opened to full aperture.

Sensitivity.

Expression of the nature of a photographic emulsion's response to light. Can be concerned with degree of sensitivity as expressed by film speed or response to light of various colours (spectral sensitivity).

Sharpness

A term used to describe the ability of a lens to render fine detail clearly; dependent on the contrast and resolution of a lens and varies with the f/stop; in general, a lens is sharpest at the middle apertures. Also technically can be explained as clarity of the photographic image in terms of focus and contrast. Largely subjective but can be measured to some extent by assessing adjacency effects, i.e. the abruptness of the change in density between adjoining areas of different tone value.

Shutter

Blades, a curtain, plate, or some other movable cover in a camera that controls the time during which light reaches the film.

Shutter Priority

An exposure mode on an automatic or autofocus camera that lets you select the desired shutter speed; the camera sets the aperture for proper exposure. If you change the shutter speed, or the light level changes, the camera adjusts the aperture automatically.

Sidelighting

Light striking the subject from the side relative to the position of the camera; produces shadows and highlights to create modelling on the subject.

Silicon.

Light-sensitive substance which generates a minute current when exposed to light.

Single Servo AF (Nikon's term)

Once the subject is in focus, focus is locked. Useful for recomposing the picture.

Single-Lens-Reflex (SLR) Camera

A type of camera that allows you to see through the camera's lens as you look in the camera's viewfinder. Other camera functions, such as light metering and flash control, also operate through the camera's lens.

Slave Unit

Accessory flash "slave" units are available to fire multiple flash units without multiple electrical connections to the camera. These units sense the light output of the first flash, which is mounted in the camera hot shoe, or cord-connected to the camera. When the light output is sensed, the slave unit triggers a second flash unit that is connected only to the slave. Additional slaves and flash units can be used, if needed.

Slow Sync

A flash technique for using the flash at a slow shutter speed. Flash shooting in dim light or at night at a fast shutter speed often results in a flash-illuminated subject against a dark background. Using a slower shutter speed with the flash brings out the background details in the picture. Use of a slow shutter speed with Rear-Curtain Sync is particularly effective for illustrating the movement of a stream of light. Can be of very creative if put to good use.

Slide

A photographic transparency (positive) mounted for projection. Represent first generation production of a image. Most agencies and photo editors demands slides than prints. Having a very tight tolerance on exposure latitudes.

Soft Focus

Produced by use of a special lens that creates soft outlines. Filters are more popular than lens as it is more economical and flexible.

SSFDC (for solid-state floppy disk)

A type of alternative source of storage medium employed by Apple's Quick-Take digital camera as opposed to ATA standard Flash Memory card.

Soft Lighting

Lighting that is low or moderate in contrast, such as on an overcast day.

SPD

Silicon Photo Diode. Battery powered light sensitive cells - the most common light reading cells for cameras, external metering devices.

Split-image.

Form of rangefinder image, bisected so that the two halves of the image are aligned only when the correct object distance is set on the instrument or. in the case of a coupled rangefinder, when the lens is correctly focused. SLR cameras may have a prismatic split-image system in their viewing screen. Works on the same principle as a microprism, and is restricted to apertures of f5.6 or greater.

Stabilizer.

Alternative to fixer where permanence is not required. Used in automatic processing machines and can now provide prints that will not deteriorate noticeably over many months if kept away from strong light.

Stain

Discoloured areas on film or paper, usually caused by contaminated developing solutions or by insufficient fixing, washing, or agitation.

Stop Bath

Darkroom material. An acid rinse, usually a weak solution of acetic acid, used as a second step when developing black-and-white film or paper. It stops development and makes the hypo (fixing bath) last longer.

Stopping Down

Changing the lens aperture to a smaller opening; for example, from f/8 to f/11. Some lenses, like PC lens or attachment with a none dedicated bellow on macro photography, stop down exposure metering is required for correct reading.

Stop-down metering.

TTL metering in which the light is measured at the picture-taking aperture. As the meter just measures the light passing through the lens, there is no need for any lens-camera interconnections.

Studio lamps (3200K).

Tungsten or tungsten halogen lamps designed for studio use. Have a longer life than photo lamps, but a lower specific output and colour temperature. Are used with type B films.

SQF

Subjective Quality Factor. Essentially a lens rating system.

Supplementary Lens.

Generally a simple positive (converging) lens used in front of the camera lens to enable it to focus at close range. Th}e effect is to provide a lens of shorter focal length without altering the lens-film separation, thus giving the extra extension required for close focusing.

SVHS

Super Video Home system. Clearer than the conventional VHS because it separates chrominance and luminance transmission

Sync Cords

The purpose of sync cords is to allow the camera to control the flash, so the flash fires at the correct time. Other common names for electrical cords to connect flash to camera are PC cord, sync cord and synch cord. One type of electrical connector on camera bodies is called a PC socket, whence the name, PC cord. Sync and synch are both intended to be abbreviations of the word synchronization.

Sync Delay

All electronic flash units require X sync, but flashbulbs require a time delay between firing the flash and opening the camera shutter. The optimum delay varies among flashbulb types, but you will get much of the flashbulb light through the shutter and onto the film even if delay is not exactly correct. Firing delay for flashbulbs is indicated by code letters:

"F"- fast; "M"- medium; "MF" - mediurn fast; "S" - slow

Sync Socket

Often called "PC terminal" or "PC Socket". Most older manual focus SLR camera bodies have this standard PC sockets which have a threaded collar surrounding the center electrical part of the socket. Some older flash units may not have a hot shoe on the flash unit and would need cable connection to fire the flash (sync) timely with the shutter. Some flash cords have a connector that makes electrical contact with the center part of the socket and is held securely in place by a threaded ring which screws into the outer part of the socket on the camera body. It is also use for multiple flash setup (non-TTL or manual) where the secondary flash can be used via a sync cord to fire at the same time.

Sync speed :

Exposure time with a focal-plane shutter is measured from the instant the first curtain is released, to begin its travel across the frame, until the instant the second curtain is released, to begin its travel across the frame. When the first curtain reaches the end of its travel, the film frame is uncovered as far as the first curtain is concerned, so it closes the electrical contacts for X sync and fires the flash instantly. Shutter speed at which the entire f iIm frame is exposed when the flash s fired in flash shooting. Most modern camera with vertical travel shutter curtain have faster flash sync speed like 1/250 sec. or slower, some top camera model like Nikon F5, changeable to 1/300 sec. with the Custom Setting.

Synchronisation.

Concerted action of shutter opening and closing of electrical contacts to fire a flashbulb or electronic flash at the correct moment to make most effficient use of the light output. Roughly speaking, FP or M-synchronisation is constructed to fire flashbulbs just before the shutter is fully open, allowing a build-up time, and X-synchronisation fires electronic flash exactly at the moment the shutter is fully open.