G
Gels
Large coloured sheets of a transparent medium which are used
over any type of light to add colour. (Also the smaller C.C.
& camera filters.)
(see CC filters)
Generator pack (Power pack)
The power pack used to link Large Studio flash lights to the
mains.
(see Monobloc)
Giclée Print
The term 'Giclée' first appeared in fine art marketing at the end of the 80's. Giclée (pronounced "zhee-clay") is french for "squirt" or "spray." Produced by a large format ink jet printer on art-quality paper or canvas. The term, however, offers no standard for quality or print longevity.
(see Fine Art & Ink Jet Print)
Gigabyte (GB, Gig)
A measure of file size and storage capacity. Most consider a kilobyte to be 1,024 bytes, a megabyte to be 1,024 kilobytes, and a gigabyte to be 1,024 megabytes. However, some key standards groups assume a kilobyte to be 1,000 bytes, a megabyte to be 1,000 kilobytes, and a gigabyte to be 1,000 megabytes. Many data storage manufacturers use this latter measurement to define their device sizes, which leads to computers showing less storage capacity on a drive than the specificiations suggests.
(see Kilobyte & Megabyte)
Gobos
Shapes made from either card or metal which when added to a suitable
light source can be projected onto "a photographic subject"
e.g. a shuttered window effect onto a table. Usually the gobo
is used inside a Focusing Spot Light, but an ordinary 35mm projector
can be used on smaller scenes!
(see Focusing Spot)
Grade
(See Contrast grade, Multigrade & Papergrade )
Grain sharp
Making a print 'grain sharp' means that it is printed in
focus.
(see Grain)
Grain
The sand-like, granular appearance of a negative, print or
trannie. Graininess becomes more noticeable with fast films and
increased size of enlargement.(Granularity: The amount
of grain clumping that has occurred within an emulsion. Also
referred to as graininess.)
(see Emulsion, Enlargement & Fast film,)
Guide number
The number which indicates the effective power of a flash unit.
For a given film speed, the guide number divided by the distance
between the flash and the subject gives the appropriate f stop
to use.
H
Hammer head
A type of larger portable battery fed flashgun (normally
a Metz)
(see Metz)
High key
Term describing a photograph which contains large areas of light
tones, with few mid-tones or shadows.
(see Low key)
High Resolution (High Res)
Refers to a relatively larger number of pixels per inch in a digital image or scan, which yields a large digital file.
Highlights
The brightest areas of the subject or photograph.
Hold-back (shading)
Photo printing method to make parts of a picture lighter
than it would normally have been.
(see Burning-in & Dodging)
Hood
A tube, usually made of metal or rubber, that prevents unwanted
light from falling on the lens surface.
(see Flare)
Hot shoe
The electrical fitting on a camera that holds a small portable
flash and links the gun to the camera shutter mechanism.. This
direct flash-to-camera contact eliminates the need for a flash
sync. cord.
(see Accessory Shoe, Flash sync. & Shutter)
Hunting
An autofocus system that has trouble finding the focus in a low
contrast image or in poor light 'hunts'; this is where the lens
moves continuously from close-up to infinity looking for the
correct point of focus .
Hyperfocal Distance
The Hyperfocal Distance or point is the nearest point to the
camera which is regarded as acceptably sharp when the lens is
focused at infinity. So when the lens is focused on the hyperfocal
point, depth of field extends from infinity back to a distance
halfway between the camera and the hyperfocal point. This method
is used in fixed focus viewfinder and 'box' cameras to obtain
a photo that would perhaps include both a far away mountain range
and a close group of people in acceptable focus.
(see Depth of Field)
Hypo
Popular name for a fixing agent, derived from an abbreviation
of hyposulfite of soda, the misnomer applied to sodium thiosulphate
during the 19th century.
(see Fix)
I
Image resolution
Digital photography: The number of pixels displayed per inch
of printed length in an image, usually measured in dots per inch
(dpi) or pixels per inch (ppi) The amount of detail in an image
depends on its pixel dimensions, while the image resolution controls
how much space the pixels are printed over. You can modify an
image's resolution without changing the actual pixel data in
the image all you change is the printed size of the image.
(see Pixel & File size)
Image Size
The dimensions of a digital image, most clearly expressed in its pixel count, horizontally and vertically.
(see Pixel)
Incident light
Light falling on a surface (as opposed to reflected by it).
(see Meter)
Incident light reading
Measurement, of the amount of incident light falling upon a subject.
The meter is placed close to the subject, pointing toward the
light.
(see Meter)
Infinity
Focusing point at which the lens gives a sharp image of very
distant objects, such as the far horizon.
Ink Jet Print
An image on paper or other material such as a canvas produced by a process that sprays dyes or pigments through tiny nozzles onto the material.
(see Giclée Print)
Iris
(see diaphragm)
ISO (International Standards Organization)
The modern speed rating for photographic materials used instead
of ASA or DIN*. The scale is identical to ASA (American Standards
Association) where the rating is based on an arithmetical progression,
using an average gradient system. Therefore ISO 200 film is twice
as fast as ISO 100 film but only half as fast as ISO 400 film.
(see ASA & DIN)
J
JPEG
JPEG (Joint Photographic Experts Group) is a file compression
method used in Digital Photography that shrinks a file's storage
size, but which can also cause image degradation as a result
of data loss.
(see Lossy)
Joule
Unit of energy in the SI (Système International) system
of units. The joule is sometimes used in photography to indicate
the output of an electronic flash.
K
Kelvin(K)
Unit of temperature in the SI (Système International)
system of units. Kelvin is used to measure the colour temperature
of light. Daylight films are designed for colour temperatures
between 5200K and 5800K.
Keystoning
Converging verticals can make a building appear to be falling
down (wider at the bottom than the top), this can be corrected
by making sure the film plane is parallel to the photographed
surface using either a Shift Lens or camera movements. It can
also be corrected within Photoshop. Keystoning is also the term
for the effect of a tilted (up or down) projector.
(see Camera movements, Converging angles, Movements, Photoshop, Rising front & Shift )
Kilobyte (KB, K)
A measure of file size and storage capacity referring to 1,000 or 1,024, 8-bit data units or characters.
(see Gigabyte)
Kodalith
Kodak trade name for Lith film.
(see Lith film)
L
Large format
As the name implies this is the largest of modern film formats
(the most popular being 5"x4" & 10"x8"),
and they are especially suitable for high quality commercial
work.
(see Medium format)
Lastolite
Well known reflector manufacturer who created the folding 'spring
out of the bag' style reflectors and Backgrounds.
(see Reflector)
Latent image
The invisible image left by the action of light on photographic
film or paper. The light changes the photosensitive salts and
when processed, this latent image will become a visible image.
Latitude
The range of camera exposures from under to over exposure that
will still produce an acceptable image from a specific film.
(See Exposure & Exposure latitude)
Leader
The beginning of a 35 mm or roll film, which is attached to the
take-up spool.
(see Roll film & 35mm)
Lens shade
A Bellows or Hood at the front of a lens that keeps unwanted
light from striking the lens and causing image flare. Should
be sized to the particular lens to avoid vignetting.
(see Bellows, Flare, Hood & Vignetting)
Lens Speed
The largest lens opening, e.g. f2 not f16. A fast lens transmits
more light and has a larger opening than a slow lens.
(see f-stop & Slow lens)
Light meter
(see: Exposure meter)
Lith film
Very high-contrast B&W film which, after correct development
with a special lith developer, gives negatives of black and white
only (with no greys).
(see Contrast & Dev.)
Long lens
Term describing a lens in which the focal length is much greater
than the diagonal of the film format (or standard lens) with
which it is used. e.g. 300mm on 35mm format where the standard
is just 50mm.
(see Focal length, Standard lens & Tele)
Lossy
Many file formats use compression to reduce the file size of
bitmap images (digital photo). Lossless techniques compress the
file without removing image detail or colour information; lossy
techniques remove detail. JPEG is the most common file format
in digital photography but this is a "Lossy" file format.
TIFF with LZW(Lemple-Zif-Welch) compression is the most popular
lossless file format.
(see JPEG & TIFF)
Low key
Term describing a photograph in which the tones are mostly
dark and there are few highlights.
(see High key)
Low Resolution (Low Res)
An image file that is one megabyte or less in size when opened in an image editing application. Useful for presentation purposes but insufficient for high quality printed reproduction except at small sizes.
(see Megabyte)
Lumen
Measurement of "candle power" or light output, a unit
of light falling on a surface.
Lux
(see Lumen)
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