Photographic terms

 

Archival Photograph

Different types of photographic paper have varying degrees of susceptibility to fading over time. The main cause of this is exposure to UV (ultra violet) light, although humidity, temperature, pollution and acidity are all contributing factors.  Archival prints are produced using acid free materials and techniques designed to promote longevity. Exposure to direct sunlight should be avoided, and UV-resistant glass can be used when framing. If these guidelines are followed, archival prints will comfortably last a lifetime, with many having a lifespan in excess of 120 years

 

Contact Print

A contact print is a photographic image produced from film without the use of an enlarger in a darkroom. The defining characteristic of a contact print is that it is made by shining light directly through the film negative or positive onto a light-sensitive material that is pressed tightly to the film.  Then the paper is developed into a contact print, with the resulting image being the same size as the film.

 

Cyanotype

Cyanotype is a photographic printing process  that gives a cyan-blue  print. The process was commercially popular in engineering and architecture circles, referred to as blueprints.  Two chemicals are used in the process, ammonium iron citrate and potassium ferricyanide. The English scientist and astronomer Sir John Herschel  discovered the process in 1842.  Though the process was developed by Herschel, he considered it as mainly a means of reproducing notes and diagrams (e.g. blueprints).  Anna Atkins, who is considered one of the first if not the first woman photographer, brought the cyanotype process to the making of camera-less photograms as early as 1843.

 

Digital Image

Digital imaging uses an electronic image sensor to record the image as a set of electronic data rather than as chemical changes on film. The image is computer processed using software such as Photoshop, and is most often printed on an Inkjet or Giclée printer, but can be stored and transmitted in electronic form. The primary artistic difference between digital and chemical photography is that chemical photography resists manipulation, while digital imaging is a highly manipulative medium. This difference allows for a degree of image post-processing that is comparatively difficult in film-based photography and permits different communicative potentials and applications.

 

Giclée or Inkjet print

Gicler, a French verb meaning 'to spurt', is an industry term for high-end inkjet printing. Giclee printing uses only archival papers which are free from the acids present in most common papers and which react with UV light to damage the paper fibers. Giclee printing also uses archival pigmented inks which are available from the best manufacturers and provide long-term resistance to fading.  Today the term “digital print” generally refers to and often has taken the place of the terms Giclée and Inkjet.

 

Platinum/palladium print

The platinum/palladium printing process provides the greatest tonal range of any printing method using chemical development. A platinum print provides a broad scale of tones from warm black, to reddish brown, to mid-tone grays that are unobtainable in silver prints. Unlike the gelatin silver print process, platinum lies on the paper surface, while silver lies in a gelatin or albumen emulsion that coats the paper. As a result, since no gelatin emulsion is used, the final platinum image is absolutely matte with a deposit of platinum (and/or palladium, its sister element which is also used in most platinum photographs) absorbed slightly into the paper. Platinum prints are the most chemically durable of all photographic processes.

 

Photogravure

Also known as heliogravure, photogravure is a photo-mechanical means of reproducing a photograph in large editions. Copper plates are acid-etched directly from an original silver print; the etched areas then hold differing amounts of ink in order to correspond to the tones of the original print. If prints remain untrimmed, the impression of the printing plate will remain on the paper around the image.  In photogravure, blacks often appear as delicate charcoals, and whites - when printed on high quality paper - remain white. The photogravure technique results in delicately beautiful prints, with excellent detail and subtle tones.

 

Silver Gelatin/Gelatin Silver Print

Silver gelatin prints typically give deep rich blacks and crisp whites on a high gloss paper. A suspension of silver salts in gelatin is applied to a support such as resin-coated paper.

When small crystals (called grains) of silver salts are exposed to light through a photographic negative, a few atoms of free metallic silver are liberated and form the image on the paper. The chemical strength, temperature, and duration of the process allow the photographer to control the contrast of the image. The development is then stopped  by neutralizing the print in a bath, removing the undeveloped silver salts by fixing in sodium or ammonium thiosulphates, then washing it in clean water. The final image consists of metallic silver embedded in the gelatin coating on the paper.

 

Vintage Print

A vintage print is one that the photographer makes shortly after shooting and developing a negative.  Photographers also make prints later over their career from the same negatives but often paper stock and emulsions change, so the print may have a different appearance than a vintage print.  Generally, vintage prints are considered to show a photographer’s original intentions for an image and often are more highly valued than later prints.  Often a photograph will be dated by the year in which the negative was taken and designated “printed later” if it is not a vintage print.

 

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