Photography

Photography is the process or art of producing images on sensitized surfaces by the chemical action of light or of other forms of radiant energy, as x-rays, gamma rays, or cosmic rays and is the result of combining several technical discoveries. 

Long before the first photographs were made, Ibn al-Haytham (Alhazen) (965-1040) invented the camera obscura and pinhole camera. Photography as a usable process goes back to the 1820s and the work of French inventor Nicéphore Niépce and Louis Daguerre.

In this section:

Archival Digital Photograph

see Giclée.

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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

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Chloro-bromide Print

Chloro-bromides share the features of all silver gelatin prints, giving deep rich blacks and crisp whites on a high gloss paper, as well as having good archival properties. Compared with silver bromides or silver chlorides, they have a warmer brownish-black tone.

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Cibachrome / Ilfochrome Classic

A particular type of reversal (R-type) colour paper and printing process which gives strong colours (often with striking reds) and creates a long-lasting print. Printing in this way from a positive image results in exactly the same colour saturation as the original, and greater contrast.

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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 softweare such as Photoshop, and is most often printed on an Inkjet or Giclee 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.

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Giclée

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 fibres. Giclee printing also uses archival pigmented inks which are available from the best manufacturers and provide long term resistance to fading. You can find further detailed information at The Fine Art Trade Guild

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Photogravure

Also known as heliogravure, photogravure is arguably the finest 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). Blacks often appear as delicate charcoals, and whites - when printed on high quality paper - remain white. The photogravure technique results in incredibly beautiful prints, with excellent detail and sensitive tones.

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Silver Gelatin Print

Silver gelatin prints typically give deep rich blacks and crisp whites on a high gloss paper. They have extremely good archival properties, lasting over 100 years without visible fading if kept carefully. There are three key types of black and white gelatin prints: silver bromide, silver chloride and chloro-bromide.

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