. With an ISO 50 ï¬lm, develop for 25% less, or 9 minutes.
. The print is washed in water, swelling the gelatine into a relief matrix that will accept greasy ink in the shadow and mid-tone areas, but repel it in the highlights (where the water content is highest). .
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. 750 mlMetol . . . .
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. . . . Fixation involves these chemical reactions (X = halide, typically Br −): AgX + 2 S 2 O 3 2− → [Ag(S 2 O 3) 2] 3− + X − AgX + 3 S 2 O 3 2− → [Ag(S 2 O 3) 3] 5− + X − In addition to thiosulphate the fixer typically contains mildly acidic compounds to adjust the pH and suppress trace amounts of the developer. . .
. . . . . . . . . . . . Oxidation is hastened by immersion in running water, which also washes away the unused iron salts.Solution A 65 g ammonium ferric citrate (green) in distilled water to make 250ml total.Paper: For all alternative processes high quality art paper such as those used in printmaking or watercolour work are most suitable.
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. . . . . . 5 gEDTA - Na4 .
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. . A basic fix should contain acidifiers but no hardeners. . . . . . . . . . 2 gEDTA* . . . . . . . . . .
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. . . . . 75 gAscorbic acid (Vitamin C) . . . . . . . . . . . . 20 gPotassium Bromide .
He observed that the dichromated colloid hardened in proportion to its exposure to sunlight, and applied the principle to an early photogravure process. .
. The citric acid is to reduce oxidation and prevent stains.Potassium ferricyanide . . .
. . . . . . His work inspired photographers whose pictorial work derived from Impressionism in fine art, and great use was made of the gum bichromate process as a method of producing the painterly images so characteristic of turn-of-the-century art photography.available as prepared liquid gum arabic (avoid acid preservatives) or mix dry gum (acacia) at 1 part to 3 parts water.
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. . . Give at least a 10% increase or decrease in time from your best guess starting time. . . . 64.0 gPotassium bromide . . . . .
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. . with distilled water before use.1.8% solution Sodium Chloride (1.8g to 100ml.
Redevelop.Print colour is controlled by varying the ratio of redeveloper solutions A and B in water:It is a good idea to prepare the chemicals at least 24 hours before use to ensure that they are completely dissolved. . . 30.0 gSodium thiosulfate . . . . . . .
. . . . . . Pre-humidifying the paper will give a cooler purple/brown. . .
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With B/W film densities build up proportionately during development, so the exposure is usually altered by shutter speed with a corresponding cut in developing time.Most of the MQ variations of D76 are published widely, but less is known about the PQ variants of Ilford's equivalent developer ID-11Although J.D. 11 gCold Water to make . . . . . . Dry thoroughly, as wet sensitiser will ruin a negative. . . . Toning takes about 5 minutes. . .