Platinotype Errata

p20, 22 – Chapter 9 not Chapter 10

See “Chapter 10” should be “Chapter 9”

p48 – plastic not glass

“glass sheets” should be “plastic sheets”

p76 – !! Method 2 preparation !!

3. With a cylinder, measure 30 ml of warm distilled water should be “3. With a cylinder, measure 23 ml of warm distilled water”

p90 – !! EDTA Disodium preparation !!

Weigh or measure out ca. 50 g of EDTA tetrasodium.
With stirring, add it to 1 liter of water
should be “EDTA disodium”

p92 – !! EDT Tetrasodium preparation !!

Weigh or measure out ca. 50 g of EDTA disodium.
With stirring, add it to 1 liter of water.”

should be “EDTA tetrasodium”

p120-121 – Pyro PMK Development

Suggested Pyro PMK Development
As suggested in Table 7.1 and 7.2, development with Pyro PMK has been increased from times recommended for printing on silver-gelatin papers, but to a much lesser degree than for developers such as Rodinal and HC-110. These adjusted times are also referred to here as ‘P’.”

should be

Suggested Pyro PMK Development
As suggested in Table 7.1, developing negatives for platinotype with recipes such as Rodinal and HC-110 is generally greater than that for making negatives to print on silver-gelatin papers. Tests, based on the normal development (“N”), will indicate an adjusted development that becomes the norm for platinotype, and may be as much as 70% greater than what is recommended by manufacturers. I refer to this adjusted normal as “P.” Table 7.1 is intended to offer only very general guidelines, with “2 to 5 stops” requiring an adjustment between P+ 30% to 10%, for instance. This is all a sliding scale. For example, with HC110 (dilution B), and HP5 film at an EI of 320, developed at 20°C, a normal development for silver gelatin printing would be 5 minutes. To make the same negative for platinotype, the time would be increased by about 50% to 7.5 minutes (“P”). If the subject brightness range was about two stops, then a further 30% would be added to “P”, resulting in a development time of about 10.25 minutes.

Table 7.2 shows development adjustments for Pyro PMK, using tray development and sheet film. Note that “P” values indicated here are already adjusted for platinotype. Also, because of the staining effect of Pyro PMK, the “P” values with this developer are only 10–20% greater than what is recommended for normal development for silver-gelatin printing. See Gordon Hutchings, The Book of Pyro, or Digital Truth, The Massive Dev Chart.