Amateur Cine World (July 1934)

"Les poe Sete and blackened in: ing org.5mm. Metol .. sc Ha” QO TELS reversal film b yp 7 QO ROC | | | Sod. sulphite .. een ee may be carried out quite easily by any Hydroquinone . . 5 OOMOES: Sod. carbonate . . Get owOL. Pot. bromide .. Si) oe Susehse sew as hme 5 mm. Reversal E 11m “ives iim x ih tide=..< hes. OnLy requirements are some 12 by 10 inch dishes made of porcelain or enamel, a wooden frame to fit into the dishes and a drum on which to dry the film. Making a Support for the Frame Two dishes are sufficient, but four or five are preferable. The developing frame is made from two pieces of wood 1 inch by } inch and 11 inches long which are connected by two pieces of 4 inch diameter dowel rod g inches long; these are provided with spacing pins (old gramophone needles will be found to serve quite well for these), placed every half inch and the whole frame given a good coat of cellulose paint and allowed to dry. A support to hold the frame while it is being wound should also be made. This may consist of two uprights of wood, about 7 inches high, with a slot cut on the top of each. Two holes are cut through the centre of each side of the frame to take a } inch diameter dowel rod which serves as a spindle for the frame to revolve upon. The drying drum may be made from two discs of plywood twelve inches in diameter, joined by six or eight lengths of dowel rod eighteen inches long and a spindle placed through the centre for the drum to revolve on. When all is ready the film is wound on to the frame and fixed each end by means of drawing pins. Developing Solutions The first developing solution, which should be used at 65 to 67 degrees F., is made up as follows: Paraphenylene diamine .. .. I80 grains. Sodium sulphite .. oe -. 34 02. Caustic soda ae ae: .. 180 grains. Potassium bromide en .. 70 grains. Phenosafranine 1 in 1000 sol. : 2 oz. Water 40 OZ. Dissolve in order given. The film is developed in this solution till the image shows through the back almost as strongly as on the front. The time will be about 10 or 12 minutes at 6s deg. F., but varies with different makes of film. When the film is fully developed it is rinsed well and reversed in the following solution. Potassium bichromate eeeTOZ: diluted Water te si Lee 2On O25 one part in ten Sulphuric acid “ ink Of j of water. Use at 65 deg. F After the film has been in this solution for one minute the white light may be turned on and the remainder of the work carried on in white light. When the negative image is entirely dissolved away (about four to five minutes) and the positive image can be seen by transmitted light, the film is again rinsed and the yellow bichromate stain 18 — Rotten Row offers pic bleached out in :— torial possibilities. This = of shot ts sa aprieac ; ; effective on 5 mm. Sodium sulphite cryst. 2 oz. Use at 65 deg. i ortho. reversal _ film Water oe ++ 40 0Z. rf ; because the sky ts not : : or 2 to 3 mins. 4 Sulphuric acid ~$02. included. Exclude the sky from the shots on After bleaching the film is again “the ea bis apa 4 right through to the back it is washed in running A ¥ H 4) WY e water for thirty minutes and wound on to the drum to dry, the surplus water being removed by means B y of a piece of wash leather, which been soaked in water and wrung out again. COLIN BUTEMENT If parts of the film are found to be too light, they may be cut out and intensified in the following solution :— Potassium bichromate Ae ees OZ Use at 65 deg. Water ae ae sn) SA OROZ. FE. Hydrochloric acid (conc.) .. 3 dms. When the black image has been converted into a buff coloured one the film is well washed in running water till the yellow stain is removed (about 20 to 30 mins.) and is then developed in the Metol-Hydroquinone developer previously used to develop the film after reversal. When the image has attained a good black colour right through to the back, the film is well washed and dried. If, on the other hand, parts of the film are too dark they may be reduced in density. Make up the following : (Continued on page 179)