International photographer (Jan-Dec 1935)

Eight The INTERNATIONAL PHOTOGRAPHER February, 1935 Minature Camera Photography ^ARAPHENYLENE DIAMINE Hydrochloride: One of the beauties of miniature camera photography is the rapid forward strides it is making. Many miniature camera workers are active experimenters, making interesting discoveries, and manufacturers also keep pace with the rapid tide of progress constantly presenting the photographer new and improved products with which to work. Paraphenylene-diamine has been serving admirably for some time, but now we have an improved product — Paraphenylene-diamine Hydrochloride, which has been announced by both the Stone Laboratories and the PhotoCrafts Laboratory, both designating it by the abbreviation P.D.H. P.D.H. has the following advantages over the plain paraphenylene-diamine : 1. It is completely soluble in cold water. 2. It is stainless — an advantage which you can well appreciate if you recall the many stains produced around the kitchen, or in the laboratory, from spilling paraphenylene-diamine solutions. 3. It is a more stable chemical and keeps well in solution. New formulas have been devised for use with Paraphenylene-diamine Hydrochloride which are reproduced below : Dr. Parker No. 78 For normal exposure. P. D. H. ---------- 3 grams 45 grains Sodium Sulphite (anhyd.) 25 grams 375 grains Verebest P. P. Phosphate 6 grams 90 grains Distilled Water ------ y2 liter 16 ounces Average developing time: 30 to 40 minutes at 70°F. Dr. Parker No. 76 For normal exposure. P. D. H. ---------- 6 grams 90 grains Sodium Sulphite (anhyd.) 30 grams 450 grains Glycin ----------- 3 grams 45 grains Verebest P. P. Phosphate 13J/S grams 40 grains Distilled Water ------ ^ liter 16 ounces Average developing time: 14 to 16 minutes at 70°F. Dr. Parker No. 72 For normal exposure. P. D. H. ---------- 6 grams 90 grains Sodium Sulphite (anhyd.) 30 grams 450 grains Glycin --- 3 grams 45 grains Verebest P. P. Phosphate 18 grams 270 grains Borax (crystals) ------ 5 grams 75 grains Distilled Water l/> liter 16 ounces Average developing time: 14 to 16 minutes at 70°F. Dr. Sense No. 3 (Modified) For double normal exposure. P. D. H. ---------- 6 grams 90 grains Sodium Sulphite (anhyd.) 45 grams \l/2 ounces Glycin ----------- 3 grams 45 grains Distilled Water ------ y2 liter 16 ounces Average developing time: 30 minutes at 65°F. ; 25 minutes at 70°F. Formula No. 78 is rated as giving the best grain whereas Formulas Nos. 72 and 76 give sufficiently fine grain for average use. A new alkali compound is listed above — Verebest Pure Photo Phosphate. This is a pure Monohydrated Sodium Phosphate distributed by the Photo Crafts Laboratories and requires only one-half of the quality of the Trisodium Phosphate because of the removal of excess water. The above formulas are those recommended by the Photo Crafts Laboratory. Below are reproduced those developed for use with P.D.H. by the Stone Laboratories. In this case you will also notice the use of a new monohydrated alkali which is distributed by the Stone Laboratories — Esspho. When using Esspho for formulas containing sodium carbonate, one-half of the amount of Esspho is used that would be required of dessicated or anhydrous carbonate, and only 40 per cent of monohydrated sodium carbonate that is required ; as in the case of Verebest P. P. Phosphate, only onehalf the amount of Esspho is used as is required of Trisodium Phosphate. Formula S-8 Produces the finest grain. For normal or overexposure. P. D. H. --------- 6 grams 90 grains Sodium Sulphite (anhyd.) 50 grams 750 grains Esspho ---- 12 grams 180 grains Water ----------- l liter 32 ounces Developing Time: All S. S. Panchromatic, 30 to 40 minutes at 70°. Plenachrome, Verichrome and F. G. Plenachrome, 35 minutes at 70°F. Panatomic and Micropan, 30 minutes at 70°F. At 65°F. increase the time five minutes. Formula S-6 For under exposure. P. D. H. --------- 6 grams 90 grains Sodium Sulphite (anhyd.) 30 grams 450 grains Glycin ----------- 3 grams 45 grains Esspho ----------- W/2 grams 200 grains Water ----------- l liter 32 ounces Developing Time: All S. S. Panchromatic, 16 to 18 minutes at 70°F. Other films, 12 to 14 minutes at 70° F. At 65°F. develop two minutes longer. Many new improved chemicals have been introduced lately which are quite a boon to the miniature photog Funnels: Exposure was made on Panatomic film, which was developed in Paraphenylene-diamine — Glycin, and printed on P. M. C. Bromide. rapher in that they represent purified high grade chemicals which will help to produce better fine-grain negatives. Amongst those are the two alkali compounds mentioned above, Pure Photo Phosphate distributed by the Photo Crafts Laboratory and Esspho distributed by the Stone Laboratories. Another new and efficient alkali Please mention The International Photographer when corresponding with advertisers.