Photographic Glossary-F


The loss of or change of colour density, generally accelerated by exposure to sunlight.

Decrease in the intensity of light as it spreads out from the source.

Fast film
Is film which has an emulsion that is very sensitive to light. These film have high ISO ratings.

Fast lens
Is a lens with a wide maximum aperture ( low f number ).

File Allocation Table. A table that an operating system maintains on a hard disk that provides a map of the clusters that a file has been stored in.

A technique in many image editing programs that allows for the softening of the edge around a selection

Fiber optics
An optical system that uses glass or transparent plastic fibers as light transmitting media. These cables have greater bandwidth than electrical transmission through wires.

Photographic papers without a plastic coating.

Field curvature
A lens aberration or defect that causes the image to be formed along a curve instead of on a flat plane.

File Converters
Hardware or software that is used to convert files from one type of file format to another format.

File format
The way a graphic file is saved. Several file format are available for use, and each one has its own advantage and disadvantage. The most popular file format include TIFF, PICS' EPS, BMP, JPEG. TIFF is the most widely used file format.

File server
A computer on a local area network that is used to store files that are shared among the users on the network.

File size
The file size of an image is proportional to its resolution. The higher the resolution, the bigger the file size. File size is different from image size.

A method of flash photography that combines flash illumination and ambient light, but does not attempt to balance these two types of illumination. A technique that uses flash illumination as a supplement to ambient light. Useful when photographing subjects that are backlit, with very high-contrast lighting or in shadow.

Fill-In Light
Additional light from a lamp, flash, or reflector; used to soften or fill in the shadows or dark picture areas caused by the brighter main light. Called fill-in flash when electronic flash is used. Also see Balanced Fill-Flash.

Secondary light source used to fill in the shadow created by the main or key light. Called fill-in flash when electronic flash is used.

Film base
Flexible support on which light sensitive emulsion is coated.

Film clips
Metal or plastic clips used to prevent the curling of the film during the drying.

Film holder
A light-tight, removable device for holding film on many medium-format. This allows the photographer to preload the film so he can quickly change rolls of film.

Film leader
Length of protective film at the beginning of a roll of unexposed or processed film.

Film plane
The plane on which the film lies in a camera. The camera lens is designed to bring images into focus precisely at the film plane in a camera to ensure correctly exposed pictures.

Film Presence Indicator Flag
Feature on Advanced Photo System cameras that indicates the film cassette has been loaded properly.

Film pressure plate
A part of the camera back which, when closed against the film guide rails, creates a very precise tunnel in which the film is flatly positioned for sharpness.

Film recorder
A device used to output digital files onto film materials. CRT film recorders use a cathode ray tube and RGB filters to create the film image. Drum-based film recorders/writers include sheet-fed and roll-fed models and use white light or lasers to record the image on film.

Film Safe
Describes the fact that film is sealed in the cassette; avoids the danger of exposure to light before shooting and mishandling of negatives after shooting.

Film scanner
A device that scans slides and negatives to create a digital image.

Film speed
A film's sensitivity to light, rated numerically so that it can be match to the camera's exposure control. Film speed ratings increase as the sensitivity of the film increases. Each time you double the film speed, half as much light is needed for correct exposure. Faster films need less light but they produce grainier pictures. Slower films have a finer grain and they produce more contrast. Pictures taken on slower films are sharper in appearance. Indicated by a number such as ISO 100 or ISO 400 etc. The sensitivity of a given film to light,. The higher the number, the more sensitive or faster (and more grainer) the film. Note: ISO stands for International Standards Organization.

Film Status Indicators
The four icons on Advanced Photo System film cassettes that show the film status - unexposed, partially exposed, fully exposed or processed.

Film trailer
Length of protective film beyond the exposed area of a roll of film.

A photographic emulsion coated on a flexible, transparent base that records images or scenes. The film is the light sensitive medium on which the photograph is recorded. There are 2 main types of film, Print film and Slide film. The material used in a camera to record a photographic image. Generally it is a light-sensitive emulsion coated on a flexible acetate or plastic base.

Filter factor
The increased exposure needed to compensate for the amount of light absorbed by a filter. A factor of two indicates you need to give the film one stop more exposure; a factor of three needs two stops and a factor of six needs three stops more.

Filter pack
Several filters used together, as in a enlarger for colour printing or when duplicating slides, in order to obtain the best or desired colour in the image.

A colored piece of glass or other transparent material used over the lens to emphasize, eliminate, or change the color or density (ND) of the entire scene or certain areas within a scene. Also see "colour temperature", "UV". Technically, it explained as a piece of material which restricts the transmission of radiation. Generally coloured to absorb light of certain colours. Can be used over light sources or over the camera lens. Camera lens filters are usually glass either dyed or sandwiching a piece of gelatin in a screw-in filter holder. Anything that is placed over the front element of the lens to alter the final image is a filter. Filters range from circular polarizers, warming filter, star filters, soft focus filters, and many colored filters to change the over all color of a photograph.
Filters often used in Black and White Photography and what types of effects you may see
Red Darkens blue skies and will improve contrast between clouds and sky. Not favorable when photographing people because the red in the lips becomes very pale. Also necessary when shooting Infrared film. Red filters cause blue/green/yellow to be darkened
Yellow Will also improve contrast between clouds and sky but to a lesser extent. Yellow is also used to produce pleasant skin tones. Yellow causes purple/blue/red to be darkened.
Green The most common use of a green filter is to produce a fair complexion in Caucasian models. Will also renders red/orange/purple to be darker.
Orange Not used very often but can be used to darken skies to produce stronger contrast between clouds and sky. Renders green/blue/purple darker than natural.
Blue Blue is also not used to a great extent. A blue filter would darken reds/oranges/yellows.

Also known as viewfinder and projected frame. A viewing device on a camera to show the subject area that will be recorded on the film.

Fine grain developers
Are film developers which help to keep grain size in the photographic image to a minimum.

Fine grain
Film or developer that produces images in which areas of uniform tone appear smooth, with no clumping of the silver particles that form the image.

A firewall is a program, usually an internet gateway server, which protects the resources of one network from users from other networks.

A very fast external bus that supports data transfer rates of up to 400 Mbps. Firewire was developed by Apple and falls under the IEEE 1394 standard. Other companies follow the IEEE 1394 but have names such as Lynx and I-Link.

Fish-eye lens
Extreme wide-angle lens with an angle of view exceeding 100 degree and sometimes in excess of 180 degree. depth of field is practically infinite and focusing is not required. Ultra-wide angle lens giving 180 angle of view. Basically produces a circular image on 35 mm, 5-9 mm lenses showing whole image, 15-17 mm lenses giving a rectangular image fitting just inside the circle, thus representing 180 across the diagonal.

Fixed focal length
Used to describe a camera with a non-removable, non-zoom lens. Because of this, the lens focal length cannot be changed.

Fixed focus
A camera where focus is not adjustable.

Fixed-Focus Lens
A lens that has been focused in a fixed position by the manufacturer. The user does not have to adjust the focus of this lens, applies on most entry or disposable cameras.

A chemical solution (sodium thiosulfate or ammonium thiosulfate) that makes a photographic image sensitive to light. The fixer stabilizes the emulsion by converting the undeveloped silver halides into water-soluble compounds, which can then be dissolved away. Also called hypo. Solution, usually based on sodium thiosulphate, in which films or prints are immersed after development to convert the unexposed silver halides in the emulsion to soluble products that can be washed out. This prevents subsequent deterioration of the image.

Fixing Bath
Darkroom material. A solution that removes any light-sensitive silver-halide crystals not acted upon by light or developer, leaving a black-and-white negative or print unalterable by further action of light. Also referred to as hypo.

Fluorite. A low dispersion mineral used as a substitute for glass in some highly corrected long focal length lenses. Canon uses most of these properties on its EF-L series long teles. Also refer to "ED".

An overall decrease in contrast caused by light being reflected off, instead of transmitted through, a lens surface; controllable through the use of multilayer coating of individual lens elements in a lens; aggravated by unclean lens surfaces on front and rear lens elements or filters.

Too low in contrast. The range in density in a negative or print is too short or in some cases, reflecting the low resolution produced by a low quality lens.

Flat Lighting
Lighting that produces very little contrast or modeling on the subject plus a minimum of shadows.

The soft effect visible in a picture resulting from stray light which passes through the lens but is not focused to form the primary image. Flare can be controlled by using optical coating, light baffles and low reflection surfaces , or a lens hood.

Flash Bracket
Often called handle mount flash. It comprised of one arm of the L-shaped bracket extends under the camera body and uses the camera's tripod socket to mount the camera on the bracket. The vertical arm of the bracket serves as a handle and mounts a flash unit in an accessory shoe often on top of the handle portion, but there are other methods. Flash mounted in a bracket usually requires a separate electrical cord to make the electrical connection between camera body and flash unit. When working with a flash in a situation where the final product is desired to be of better quality than a snapshot and a flash is needed, a flash bracket is a necessity. A flash bracket will allow the flash to be positioned directly above the camera to help to eliminate the harsh shadows that are often seen in simple snap shots. It can also be used to eliminate Red Eye.

Flash bracket
When working with a flash in a situation where the final product is desired to be of better quality than a snapshot and a flash is needed, a flash bracket is a necessity. A flash bracket will allow the flash to be positioned directly above the camera to help to eliminate the harsh shadows that are often seen in simple snap shots.

Flash card
A memory card that works with the flash memory, allowing the camera to retain data after the system has been turned off.

Flash duration
Refers to the amount of time it takes for a flash to fire. Flash duration typically varies from about 1/1000 to 1/20,000 sec.

Flash Exposure Bracketing
Enables a photographer to automatically bracket exposures at varied flash output levels, in TTL auto flash shooting, without changing the shutter speed and/or aperture, this is a one of the top flash feature that can only be found on some higher ranked cameras.

Flash factor
Is a number which provides a guide to correct exposure when using Flash. See also Guide number

Flash Head
Professional studio lights often utilize a centralized power pack to provide power to multiple flash heads. These flash heads simply contain modeling lights, flash bulbs, and hardware to allow connections for light modifiers such as Grids/Gobos, umbrellas, soft boxes, or barn doors.

Flash Memory Card
A storage medium that uses by most digital cameras. It resembles film in conventional photography. We have an detailed article relating to this.

Flash memory
A memory chip that has the ability to retain image data even after the host system has been shut off; this feature insures that, even if the digital camera's batteries die, the image data will remain stored in the camera's memory. Fringing: Fringing occurs when a digital image is sharpened. The term usually refers to a white fringe appearing on the edges of objects in the image. Fringing can also occur as a result of compression.

Flash meter
A device for measuring the light coming from a electronic flash and indicating the appropriate aperture for correct exposure. Some flash meter can also measure the ambient light.

Flash output level compensation
A control used to adjust a TTL auto flash operation, enabling an increase or decrease of flash output to lighten or darken the flash effect

Flash range
The maximum distance from which a flash can effectively illuminate a subject. Most built-in flashes are effective to about 12-15 feet. Range varies by brand, so check the specification carefully.

Flash shooting distance range
The distance range over which a flash can effectively provide light. Flash shooting distance range is controlled by the amount of flash output available. Each automatic Speedlight's flash output varies from maximum duration to minimum duration Close-up subjects will require lower (to minimum) output while more distant subjects will require more light up to the maximum output. The flash shooting distance range varies with the aperture, film speed, etc.

Flash 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 film fame 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.

Flash sync
A special socket on a camera that allows the attachment of an auxiliary strobe light for flash pictures. It is synchronized to the camera's shutter so the light goes off at the right time. T he maximum shutter speed which the flash can fire and properly expose the full frame. Cameras which use a leaf shutter, such as a many twin lens reflex cameras (TLR) and many medium format cameras where the shutter is contained within the lens, not the camera body, can sync at any speed due to the way the shutter opens and closes. Cameras with a vertical or horizontal focal plane shutter, as in most 35mm cameras where the shutter is a curtain which travels immediately in front of the film, have a maximum speed at which the flash can fire. When a camera utilizing a focal plane shutter is fired, the first curtain is released to travel across the film plane, then the second (or rear) curtain will close behind the first curtain. Depending on the shutter speed chosen, this defines the gap between the two curtains. In order for the flash to properly expose the film, the separation must be great enough for the film to be fully exposed to the full duration of the flash. If the shutter speed is too fast, then the rear curtain will beginning to close before the flash is firing, causing either the left (for horizontal curtain) or top (for vertical curtain) to be underexposed. Some of the current professional level cameras have very fast shutter of upwards of 1/8000 shutter speed. Most 35mm cameras can sync between 1/60th and 1/250th of a second. To determine what speed your camera syncs at either read the manual, or look at the dial on the camera and look for the shutter speed setting with the lightning bolt, or x beside the number. If the camera has a pop up flash, such as a Canon EOS 2000, another way to determine the max speed is to engage the flash, the increase the shutter speed until the onboard computers force it to stop. Most will not let the camera be set faster than the flash sync speed.

Flash synchronization
Timing of the flash coincides with release of the camera's shutter. There are two types of synchronization: Front-Curtain Sync, which fires the flash at the start of the exposure, and Rear-Curtain Sync, which fires the flash at the end of the exposure. Also see "Rear-Curtain Sync", "Front-Curtain Sync", "X setting".

The artificial light source in the dark. Electronic flash requires a high voltage, usually obtained from batteries through a voltage-multiplying circuit. It has a brief, intense burst of light, usually used where the lighting on the scene is inadequate for picture-taking. They are generally considered to have the same photographic effect as daylight. Most flash will correct the color temperature back to 5000 Kelvin - the daylight color. You can play around with filters mounting on the flash head for some specific effects or alter the color if necessary. Modern flash has multiple TTL flash exposure control functions and even extend to autofocus control. Some specialized flash are high speed repeating flash which can use for stroboscopic effect, UV-flash for ultra violet light photography etc.

Light source based on ignition of combustible metal wire in a gas filled transparent envelope. Popular sizes are usually blue-coated to give light approximating to daylight. Flash bulbs come in various sizes and types. All work by burning metal' foil in an oxygen 'atmosphere within the glass bulb. Because the light is caused by combustion inside the glass envelope, light intensity increases from zero as combustion begins. It reaches a peak value and then falls off as combustion ends. The flash unit is fired or triggered by the shutter mechanism in the camera. For some flashbulb types in some cameras, the shutter mechanism fires the flash and then waits for a specified time delay before it actually opens the shutter. This delay is to allow the flash bulb to get up to full brightness. See more on FP (focal plane bulb) section.

Self-contained unit comprising four small flashbulbs with own reflectors. Designed to rotate in special camera socket as film is wound on. Can be used in a special adapter on cameras without the socket. But will not rotate automatically.

Pre-exposing the paper to a very diffused white light in order to reduce the contrast level between the highlights and shadows and extend the tonal range.

A scene, negative, or print with very little difference in brightness between light and dark areas.

Flatbed scanner
An optical scanner in which the original image remains stationary while the sensors (usually a CCD linear array) passes over or under it. The scanned material is held flat rather than being wrapped around a drum.

To combine together multiple layers and other elements of a digitally manipulated or composite image into one. Usually final step of working with layers prior to saving images in standard image format. Otherwise, save must be in native format.

Flexible Program
Flexible Program function temporarily shifts an automatically selected shutter speed/aperture combination while maintaining correct exposure. That is, a desired shutter speed or aperture can be selected in Programmed Auto exposure mode.

A perceivable fluctuation of the brightness levels of a displayed image. This problem is often present in CRT monitors that have a vertical scan rate that is lower than 50 Hz.

Floating selection
A moveable selection that is active and above a layer. A floating selection can be manipulated without affecting the pixel data underneath it.

An electric light designed to produce a broad, relatively diffused beam of light.

A number that indicates the size of the lens opening on an adjustable camera. The common f-numbers are f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, and f/22. The larger the f-number, the smaller the lens opening. In this series, f/1.4 is the largest lens opening and f/22 is the smallest. Also called f-stops, they work in conjunction with shutter speeds to indicate exposure settings. Also can be explained as numerical expression of the relative aperture of a lens at its different stops; equal to the focal length divided by the effective aperture of the lens opening and written in various forms, such as f/8, f8, 1: 8, etc.; each f-number is 1.4 times larger than the preceding one; each number indicates a halving or doubling of the amount of light allowed to pass through the lens; the next higher numbered f-number signifies an aperture which lets in exactly onehalf as much light, and the next lower number, twice as much light, i.e., f/11 lets in half as much light as f/8, while f/5.6 lets in twice as much; all lenses stopped down to the same f-number produce images of equal illumination (apart from differences due to varying reflection losses); therefore, for a given shutter speed, a given f-number always corresponds to the same exposure. The number resulting when the focal length of a lens is divided by the diameter of the aperture. A sequence of f-numbers calibrates the aperture in regular steps (know as stops) between the minimum and maximum openings of the lens. The f-numbers generally follow a standard sequence, in such a way that the interval between one full stop and the next represents halving or doubling in the image brightness. Also called f-stop or relative aperture. The f-number becomes progressively higher as the aperture is reduced to allow in less light; i.e. f/5.6, f/8, f/11, f/16, f/22, f/32... Theoretically, all lenses at the same f-number produce images of equal brightness. The numbers on the lens aperture ring and the camera's LCD (where applies) that indicate the relative size of the lens aperture opening. The f-number series is a geometric progression based on changes in the size of the lens aperture, as it is opened and closed. As the scale rises. each number is multiplied by a factor of 1.4. The standard numbers for Calibration are 1.0,1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32, etc., and each change results in a doubling or halving of the amount of light transmitted by the lens to the film plane. Basically, calculated from the focal length of the lens divided by the diameter of the bundle of light rays entering the lens and passing through the aperture in the iris diaphragm.

Focal Length
The distance between the film and the optical center of the lens when the lens is focused on infinity. The focal length of the lens on most adjustable cameras is marked in millimetres on the lens mount. The distance from the principal point to the focal point. In 35mm-format cameras, lenses with a focal length of approx. 50mm are called normal or standard lenses. Lenses with a focal length less than approx. 35mm are called wide angle lenses, and lenses with a focal length more than approx. 85mm are called telephoto lenses. Lenses which allow the user to continuously vary the focal length without changing focus are called zoom lenses .

Focal length
The distance, usually given in millimeters, between the optical center of a lens and the point at which rays of light from objects at infinity are brought to focus. In general, the greater the focal length, the smaller and more magnified the part of the scene, it includes in the picture frame.

Focal Plane Shutter
There are two options of shutter systems available, one is the Leaf Shutter, the other is focal plane. Focal plane shutters rely on either a horizontal or vertical shutter curtain which lies directly in front of the film, at the plane of focus. Focal Plane Shutters are capable of very high speeds, in excess of 1/ 8000 th of a second. The disadvantage is much slower Flash synch speeds. A camera mechanism that admits light to expose film by moving a slit or opening in a roller blind just in front of the film (focal) plane.

Focal plane
The plane on which the image of a subject is brought to focus behind the lens. To produce a sharp picture, the lens must be focused so that this place coincides with the plane on which the film sits. Also called the film plane.

Focal point
The point on the optical axis where light rays form a sharp image of a subject. An ideal lens would allow light rays to diverge from a subject parallel to the optical axis and converge to a point when they pass through the lens.

Focal range
In photography, the portion of an object that is in focus. Also called Depth of field.

Focal-Plane Shutter
An opaque curtain containing a slit that moves directly across in front of the film in a camera and allows image-forming light to strike the film.

Focus Range
The range within which a camera is able to focus on the selected picture subject - 4 feet to infinity - for example.

Focus Tracking
Enables the camera to analyze the speed of the moving subject according to the focus data detected, and to obtain correct focus by anticipating the subject's position and driving the lens to that position at the exact moment of exposure, basically a Nikon's and Canon's feature. Currently, Nikon lead the pack in this technology with the F5, the fastest among all.

Adjustment of the distance setting on a lens to define the subject sharply. Generally, the act of adjusting a lens to produce a sharp image. In a camera, this is effected by moving the lens bodily towards or away from the film or by moving the front part of the lens towards or away from the rear part, thus altering its focal length. Position in which rays of light from a lens converge to form a sharp image.

Focusing cloth
A dark cloth used in focusing a view camera. The cloth fits over the camera back and the photographer's head to keep out light and to make the ground glass image easier to see.

Focusing screen
Used for focusing on a subject or composing a picture; the focusing screen is located at a position equivalent to that of the film plane. To provide dispersion, a matte field made of specially ground glass or plastic is generally used for focusing screens.

System of moving the lens in relation to the image plane so as to obtain the required degree of sharpness of the film.

Focus-Priority for autofocus
Shutter cannot be released until the subject s in focus. For situations when an in-focus subject s important. With the F5 camera body, Focus-Priority s given to Single Servo AF mode while Release-Priority is given to Continuous Servo AF. Using Custom Setting, however, you can change the priority to Release-Priority Single Servo AF or Focus-Priority Continuous Servo AF.

An overall density in the photographic image cause by unintentional exposure to light or unwanted chemical activity.

Darkening or discoloring of a negative or print or lightening or discoloring of a slide caused by exposure to nonimage-forming light to which the photographic material is sensitive, too much handling in air during development, over-development, outdated film or paper, or storage of film or paper in a hot, humid place.

Foreground colour
This is the colour that is used when painting, filling, and creating text.

Area in an image closer than the main subject. The area between the camera and the principal subject.

The actual size of the photograph, either slide or negative, produced by a camera; in 35mm photography, the picture measures 24mm x 36mm and has a diagonal of 43mm, While the new APS (Advance Photo System), several new formats were included, including panorama . While it can also be explained as shape and size of image provided by camera or presented in final print or transparency. Governed in the camera by the opening at the rear of the body over which the film passes or is placed. The standard 35 mm format is 36 x 24 mm; half-frame, 18 x 24 mm; 126 size, 28 x 28 mm; 110, 17 x 13 mm; standard roll film (120 size), 2x 2 in.

Completely erasing and resetting a camera's memory card. This is usually done as a quick way to erase a full card that you want to reuse or to attempt to fix a card that can't be recognized by the digital camera.

Four-colour process
Colour printing with cyan, magenta, yellow, and black inks.

FP (Focal Plane) flash Bulb
A special flashbulb that can be used at certain shutter speeds is called "FP" where the initials stand for Focal Plane. Designed for use with focal-plane shutters these bulbs make a nearly uniform amount of light for a relatively long time. Generally, FP flashbulbs can be used with any shutter speed and any firing delay except "X sync". The FP bulb will extinguish during exposure intervals longer than 1/60 second but enough light will have reached the film to make the exposure.

Frames per second. Used to describe how many frames can the motor drive or winder can handle automatically on winding per second consequently. Also apply to areas like video, animations, movie cameras.

Fractal Image
An image that is created by mathematically generated geometric shapes containing an infinite amount of image detail. A mathematically generated pattern that is reproducible at any magnification or reduction.

Frame Buffer
An area in RAM memory set aside to specifically hold the data for the screen display.

One individual picture on a roll of film. Also can apply to a object that can be utilised (tree branch, arch, etc.) to frame a subject in composition.

Free working distance
In close-up photography, the distance between the front of the lens and the subject; increases as the focal length increases; important consideration when photographing shy or dangerous subjects or when using supplementary illumination.

Pattern of a special form of condenser lens consisting of a series of concentric stepped rings, each ring a section of a convex surface which would, if continued, form a much thicker lens. Used on focusing screens to distribute image brightness evenly over the screen.

This occurs when a digital image is artificially sharpened. The term usually refers to a white fringe that is apparent on the edges of objects in the picture. Fringing can also occur as a result of compression.

Front-Curtain Sync
The flash fires an instant after the front curtain of a focal plane shutter has completed its travel across the film plane. This is the way the camera operates with the flash sync mode at Normal Sync. (See "Rear-Curtain Sync".)

Light shining on the side of the subject facing the camera.

Fellow of the Royal Photographic Society of Great Britain. Most salon photographers dream to have a title on their belt. A recognition that a photographers' standard in photographic field.

A number that indicates the relative size of the opening of the lens (aperture) and written, for example, as f/16. Because the number is obtained by dividing the focal length of a lens by it's effective aperture, the larger the aperture, the smaller the f-number. In the conventional series, each number represents an aperture that admits half as much light as the preceding one. Thus f/16 lets half as much light as a lens opened to f/11.

One F-stop, or stop for short, is equal to changing the amount of light that reaches the film by a factor of two. When changing the aperture from a 2 to a 2.8 the amount of light that reaches the film is 1/2 of the original. In comparison changing from a 2 to a 1.4 doubles the amount of light. Stops are also equivalent to shutter speed settings. 1/ 60 th seconds allows half the amount of light to reach the film as 1/ 125 thseconds. Because stops are equivalent whether it is shutter speed or aperture, it is possible to properly expose a frame with many settings. 1/ 125 thseconds at f 2.8 is the same as 1/ 250 thseconds at f 2.0. This factor can be useful if one is trying to intentionally blur a shot such as flowing water, or increase or decrease depth of field for a given subject.

File Transfer Protocol. This is the language used for file transfer from computer to computer across the WWW. An anonymous FTP is a file transfer between locations that does not require users to identify themselves with a password or log-in. An anonymous FTP is not secure, because it can be accessed by any other user of the WWW.

Full aperture metering
TTL metering systems in which the camera simulates the effect of stopping down the lens when the aperture ring is turned, while leaving the diaphragm at full aperture to give full focusing screen brilliance. The meter must be "programmed" with the actual full aperture, and the diaphragm ring setting.

Full frame
Show all of the image; mask to image on sides if necessary. Also, "NC": no crop on photo required.

Full scale
Describes a print having a wide range of tonal values from deep, rich black through many shades of gray to brilliant white

Full stop
A change in aperture or shutter speed that admits half as much or twice as much light.

The amount of anti-aliasing along the edges of a selection.