Pathescope Ltd, B&W Reversal Processing

[Ian Grant]

First Developer

Sodium Sulphite (anhyd) 20g
Para-phenylene-diamine 10g
Potassium Bromide 4g
Sodium Hydroxide 8g
Water to make 1 litre

Develop 17 - 18°C (62 -64°F) 8-10 minutes
Wash 7-10 mins

All other solutions at 16 -17°C (60 -62°F)

Reversal & Clearing

Reversal Bath

Water 750ml
Potassium Dichromate 5g
Sulphuric acid (conc) 10 ml
Water to 1 litre

ADD THE SULPHURIC ACID DROP BY DROP TO THE 750ml WITH CARE.

Reversal 5 - 7 minutes

Wash 1 - 2 minutes

Clearing Bath

Sodium Sulphite (anhyd) 20g
Sodium Hydroxide 0.8g
Water to 1 litre

Clear for 2 - 3 minutes

Second Exposure

Expose to white light. No specific time is given but 5 - 10 mins 1.5 metres from 500 watt bulb should be sufficient

Second Development

Metol 2g
Hydroquinone 10g
Sodium Sulphite (anhyd) 75g
Sodium Carbonate (anhyd) 25g
Potassium Bromide 2g
Water to make 1 litre

Development to finality, approx 3 minutes.
Wash 10 minutes

Fixing

Sodium Thiosulphate 250g
Sodium Metabisulphite 20g
Water to 1 litre

Wash for 20 minutes

[Ian Grant]

Pathescope Ltd, 1954

First Developer

Sodium Sulphite (anhyd) 70 g
Hydroquinone 10 g
Sodium Carbonate (anhyd) 35g
Potassium Bromide 8 g
Potassium Thiocyanate 3 g
Sodium Hydroxide 5 g
Water to 1 litre