Encyclopedia

Silver photography encyclopedia

120 : film format for medium format 6 cm wide.

135 : 24 x 36 mm «standard» film format.

A

Absorption: loss of some of the light rays during reflection or transmission. The selective absorption of light is at the origin of the color.

Acetic acid: acid used to make the stop bath for development and black and white printing (usually at a concentration of 2%). Found in white vinegar.

Acutance: is said of a film rendering a good sharpness.

Advanced treatment: increase in the development time of a film exposed to a sensitivity lower than that recommended.

Angle of Field: the maximum angle framed by the lens (in degrees).

Approach lens: filter that is screwed on the front of a lens to reduce the distance of shooting.

APS: “Advanced Photographic System”. Photographic cartridge characterized by a 17 x 30 mm image on a 135 film. The film has a magnetic backbone recording certain data, including the format of the chosen frame (“H” for the full 16/9 format, “C” for the classic 2/3 format and “P” for the panoramic 1/3 format). The machine at the laboratory then automatically prints the photo in the desired frame.

ASA: “American Standard Association”. American Sensitivity Scale.

Autochrome: sensitive surface created in 1904 by the Lumière brothers. Cast on the spot as glass, this emulsion gave a positive color image.

Autofocus: automatic focusing system.

B

Background: lies behind the foreground which is often the main subject of photography.

Backlight: a situation where the main subject is less enlightened than the background.

Barite: is a thick support for black and white photo film prints. The latter has a smooth and icy surface. Whites are obtained by barium sulphate, also known as barium.

Bichromate gum: photographic process based on gum Arabic.

Bracketting: technique consisting in systematically taking several views with different exposure settings.

C

C-41 : treatment of color negative films.

Chassis: film loading system for camera.

Chromatic aberration: optical aberration that produces different focus depending on the wavelength. A blurred image with iridescent contours is observed. It results from the decomposition of white light into several wavelengths. 

Cibrachrome: color printing of the slides, based on the destruction of dyes.

Contact print: a print technique where the resulting image is the same size as the original negative. Does not require a magnifier.

Contact sheet: Drawing of all the images of a film on a single sheet.

Contrast: the gap between the darkest and brightest parts of an image.

Cropping: Cutting a part of the image.

Cross-treatment: processing a film in a chemistry that is not intended for it.

Cyanotype: contact drawing technique based on the formation of a Prussian blue precipitate.

D

Densitometer: a device for measuring density.

Density: the ability of a print not to reflect light. The ability of a film not to let light through.

Depth of field: area of sharpness.

Developer: a chemical used to reveal latent images.

Development: chemical treatment to reveal a latent image for a film or paper.

Deviation from the law of reciprocity or Schwarzschild Effect: the sensitivity of a film drops when working at exposure times well below 1/8th of a second, or much faster at 1/1000th of a second. The difference in exposure time between the theoretical one and the one that must be practiced to obtain a properly exposed image is the deviation to the law of reciprocity.

Diaphragm: aperture of the device allowing light to pass through.

Diffraction: changes in the orientation of the light rays resulting in a loss of sharpness.

Diffuser: filter to soften the light of a lighting.

DIN “Deutsche Industrie Normen”: german film sensitivity scale.

Dmax: maximum density (black) that can reach a film or paper.

E

E-6 : slide development.

Enlarger: a photographic laboratory device that allows an image to be enlarged from a photographic film.

Emulsion: suspension of photo-sensitive particles.

Exposure: choice of speed/diaphragm torque.

Exposure latitude: the ability of a film to record contrast deviations.

Extension ring: accessory inserted between the lens and the case to make macrophotography.

F

F/ : diaphragm value.

Film lith: film with very strong contrast.

Film shot: large-format film (larger than 120).

Filter: transparent surface placed in front of the lens altering the rendering of the image.

Fixing: operation that makes a photographic image insensitive to light

Flash: short lighting system.

Flare: reflection or light diffusion linked to a frontal light.

Flexible trigger: cable to trigger without risk of moving the device.

Focal length: distance between diaphragm and photosensitive surface.

Focus: definition of the sharpness zone on the subject.

G

Gamma: the contrast value of a film after development.

Gradation (Grade): scale indicating the contrast of black and white photographic papers.

Grain: distinction of silver grains after the development of a film.

H

High key: image whose light tones predominate.

High lights: very bright areas of a subject.

Homothetic: means a print that respects the proportions of a negative.

I

Icing: drying at high temperature of a barium print, emulsion against a stainless steel plate.

Inactinic: color that does not veil orthochromatic photo papers.

Infrared film: film sensitive to infrared.

Integral measurement: measurement of light over the entire shot.

Internegative: countertype for contact prints.

Inversible: Directly giving the positive values of an image.

ISO: standard sensitivity scale combining ASA/DIN.

K

Kelvin: unit defining the color temperature.

L

Latent image: image not yet revealed on film or paper.

Light meter: device for measuring the light received by the subject.

Low key: image with dark tones predominating.

M

Macrophotography: photography of very small objects.

Make-up: done in print by protecting or overexposing specific areas to change the rendering of the image.

Multizone or Matrix Measurement: Measurement of light on multiple parts of the image.

N

Newton’s rings: the figure of interference obtained by placing a lens on a flat surface. A series of concentric rings, alternately bright and dark, can be observed centered on the point of contact between the spherical surface of the lens and the flat surface. These rings can be found when using a pass-through or scanner.

O

Orthochromatic film: film sensitive to blue and green but not to red.

Overexposure: a situation where the film has received too much light.

P

Pan: framing a photo according to the ratio 1/2.

Panchromatic film: film sensitive to all wavelengths.

Parallax error: difference in view space between the viewfinder and the lens

Pinhole: camera without lenses.

Proof: silver print.

Proxiphotography: close-up photography (before macrophotography).

R

Reflex: type of camera where the aim is made to work the objective.

Repique: manual intervention on a photo print to remove white spots due to dust.

Retouching: manual intervention on a print to correct defects.

Room: large format camera.

S

Salt paper: contact drawing technique based on the creation of silver chloride from sodium chloride and silver nitrate.

Saturation: intensity of the color.

Selective measurement (spot): measurement of light only on the subject.

Self-timer: system to delay the release.

Sensitivity: the ability of a surface to capture light. The more sensitive the surface, the less light is needed.

Silver: is said to be traditional photography and all processes based on the sensitivity of silver to light.

Slide: a transparent image on which the image appears with its normal (positive) values.

Solarization: photographic effect caused by the localized inversion of certain black parts of an image. It can be obtained by an insolation during the development of the film or the print.

Stopper bath: solution used between the developer and the fixative, to remove the action of the developer.

T

Toggle: system to exaggerate or correct the perspective between the top and bottom of the image on a camera.

U

Underexposure: a situation where the film has received too little light.Underexposure: a situation where the film has received too little light.

V

Van Dike: contact printing technique in brown tone.

Veil: involuntary density appearing on a film or paper due to a scattering of light.

Vignetting: a defect in an image that darkens the corners.

W

Weighted Measure: an integral measure, but with a focus on the part of the subject considered to be the main one.

White balance: adjustment of the chromatic balance according to the color temperature.