A F OWl MANUAt oiPHM-TECHNiaUE CORNELL UNIVERSITY LIBRARY FINE ARTS LIBRARY TR 290.Jl'"l972"""""'"-"'"'^ mmmmmEim^ negative technique 3 1924 015 369 055 The original of tliis book is in tlie Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924015369055 The Manual of Photo-Technique a' THE MANUAL OF PHOTO-TECHNIQUE Camera Techniques H. J. WALLS, B.SC, PH.D. Exposure W. F. BERG, D.SC, F.INST.P., F.R.P.S. Optics ARTHUR COX, M.A., B.SC, F.INST.P. Enlarging C. I. JACOBSON, PH.D. AND L. A. MANNHEIM, M.A. Developing C. I. JACOBSON, PH.D. AND R. E. JACOBSON, M.SC, PH.D., A.R.LC. Retouching O. R. CROY, PH.D. Basic Sensitometry L. LOBEL, I.C.P. AND M. DUBOIS, I.C.P. Stereo Photography K. C. M. SYMONS, D.L.C., A.M.I.I.A. Colour Prints J. H. COOTE, F.R.P.S., F.B.K.S. Colour Films C. LESLIE THOMSON B.SC. Colour Separation Negatives PHILIP JENKINS C. I. JACOBSON,/'^.Z>. and R. E. JACOBSON, M.Sc, PH.D., A.R.I.C. Developing THE NEGATIVE TECHNIQUE EIGHTEENTH EDITION FOCAL PRESS London and New York Distributed in the U.S.A. by AMPHOTO 915 Broadway, New York, N.Y. 10010 © 1972 FOCAL PRESS LIMITED First published in U.S.A. 1972 0-8174-0626-3 Library of Congress Catalogue Card No. 77-107002 All Rights Reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the Copyright owner. First Edition This book was first published in May 1940 and has been reissued seventeen times since that date. There is probably no other work on this subject that has served so many readers so long and so well as an authoritative source of reference. Every edition preceding the Seventeenth had been brought up-to-date in the hght of current progress. Yet after thirty years of wear and tear the time had come to reconsider the subject as a whole and so the last edition was reshaped to suit the prevailing trends. Thirty years ago photographic processing was still some- thing of a pastime which seemed to thrive on a spirit of experimentation and even controversy. The changing social structure, economics and technology of our day combine to evoke more uniform and thus more reliable concepts of developing standards and control. This is a field in which increasing automation is both desirable and feasible. The basics of processing chemistry may not have changed a great deal, but the approach to its technology has. The range of developing agents is as wide as ever but only a few of them are consistently used in practice and optimum results are simply achieved by an informed choice of the correct formulation. So the extensively revised Seventeenth and the present Eighteenth Edition, which has undergone further revision, present a very comprehensive survey of formulae, whenever possible in compact comparative tables. Professional and commercial practices are covered more extensively than in the preceding editions. In this latest Edition, the Eighteenth, techniques of pro- cessing have again been revised to include rapid daylight in-cassette processing of 35 mm. film and modern tube and drum processors suitable for the professional. In the rapid access field, formulae for ultra-rapid processing are given as well as the Bimat and Dry Silver process. Processing formulae have been brought up-to-date and wherever possible general tables of developer formulae are given. Low contrast and stabilised physical developer formulae are now included. Reversal processing has been completely revised and so have formulae for processing of colour materials. Specific formulae are given for processing a variety of currently avail- able colour negative and colour reversal materials. A short chapter on quality control has novi' been included which gives details of typical practical process control systems for both black and white and colour negative materials. A. Kraszna-Krausz Contents DEVELOPMENT—WHAT IT IS AND WHAT IT DOES 21 The Negative 22 Development: A Reduction Process 22 Chemical and Physical Development 23 EMULSION SENSITIVITY AND GRADATION 24 Comparing the Sensitivity of two Films 24 Measurements of Sensitivity 29 Gradation 32 Characteristic Curves 32 Gamma 35 Time-Gamma Curves 35 Determination of Development Time 38 Contrast Index _ 40 Average Gradient (G, "Gee Bar") 40 Densitometers 42 "Diffuse Density" 42 Visual Densitometers 44 Photo-Electric Densitometers 44 IMAGE STRUCTURE 50 Grain and Development 50 Granularity and Graininess 54 Negative Granularity 54 Print Graininess 55 , Resolving Power 55 Irradiation 56 Halation 58 Image Sharpness 58 Modulation Transfer Characteristics 62 The Choice of Film and Developer 64 Optimum Exposure 66 Quality of the Negative 67 THE PROGRESS OF DEVELOPMENT 70 The Rate of Development 70 The Influence of Temperature 72 When is the Developer Exhausted? 74 Developer Replenishers 76 Development Effects 77 The Influence of Agitation 78 THE COMPOSITION OF THE DEVELOPER 80 The Preservative 80 The Alkali (or Accelerator) 84 Alkalies and pH Values 1 Low Contrast Developers 180 Other Developing Agents 194 Tank Developers 200 Fine Grain Developers 202 Principles of Fine Grain Development 203 Medium Fine Grain Developers 204 Emulsion Speed and Fine Grain Development 208 Super-Fine Grain Developers 208 Special Techniques with Meritol 211 Fiigh-Definition (High Acutance) Developers 214 Inversion Agitation • 217 Physical Development 218 Tanning Developers 222 Chromogenic Developers 223 Tropical Developers 226 Prc-Hardener 227 At Higher Temperatures 228 Addition of Sodium Sulphate 228 Special Tropical Developer Formulae 228 Low-Temperature Development 230 Factorial Development 23 Quick-Finish (Rapid Access) Developers 233 Two-Bath Development 234 Multi-Solution Technique 238 Inorganic Developers 240 Restrained Development 241 Reversal Development 243 Reversal of Process Materials by the Etch-Bleach Process 249 Electrolytic Development 249 Basic Formulae 250 Desensitising 251 INCREASING FILM SPEED 256 Hypersensitising 256 Bathing 257 Vapour Treatment 257 Fogging by Light 258 Latent Image Intensification 258 Vapour Latensification 259 Post-Exposure Fogging 260 High-Energy Development 260 Development to Completion 262 FIXING 263 What the Process is and how it Works 263 Rate of Fixation 265 Life and Capacity of Fixing Baths 268 Rinse and Stop-Baths 271 Plain or Neutral Fixing Bath 272 Acid Fixing Baths 272 Hardening and Fixing Baths 273 Rapid Fixing Baths 276 Fixing Bath Maintenance and Regeneration 276 Monobaths 278 Fixing at Low Temperatures 282 The Recovery of Silver 282 Determining the Amount of Silver in Fixing Baths 283 Electrolytic Recovery of Silver 285 Precipitation of Silver by Other Metals 286 Precipitation of the Silver by Sulphide 287 Precipitation with Sodium Hydrosulphite 289 Regeneration of the Fixing Bath 289 WASHING AND DRYING 290 Technique of Washing 290 Washing in Sea Water 291 Control of Washing 291 Shortening Washing by Chemical Means 292 Drying 294 Stabilization 296 Formulation of Stabilizers 299 Improvement of Stability 299 RAPID ACCESS PROCESSES 301 Cell and Chamber Processors 301 Viscous Layer Applicators 304 Porous Plate and Roller Applicators 305 Jet Spray and Slit Processors 306 Roller Applicators 307 Saturated Web Applicators 314 "Dry" Development 314 "Photo" Development 316 Dry Silver Process 317 Chemical Transfer Processing 318 Combined Camera-Processors-Viewers 337 Formulae for Rapid Processing 337 AFTER TREATMENT OF THE NEGATIVE 339 Reduction 339 Subtractive Reducers 342 Proportional Reducers 343 Super-Proportional Reducers 344 Re-Development 345 Intensification 347 Mercury Intensifier 348 Mercuric Iodide Intensifier 350 Uranium Intensifier 350 Chromium Intensification 351 Copper-Silver Intensifier 351 Quinone-Thiosulphate Intensifier 352 RETOUCHING 354 Plan of Work 354 Partial Reduction or Intensification 355 10 Shading and Blocking Out 356 Spotting 357 Dry Reduction 357 Knifing 35g PendJ Retouching 359 Varnishing 359 Applying the Varnish 361 Pencils for Retouching 36i PROCESSING COLOUR FILMS 363 "OflBcial" and "Substitute" Formulae 364 Colour Negative Film 369 Colour Development 37O Stop-Bath 371 Hardening Bath 372 Bleach- and Fixing-Baths 372 Colour Reversal Processing 374 First Development 375 Colour Development 377 General Simimary of Operations for Colour Processing 380 QUALITY CONTROL 384 Process Control Chart 384 Colour Process Control 386 PRESERVING THE NEGATIVE 388 Plate and Flat-Film Negatives 388 Roll-Film Negatives 388 Cleaning FUm 389 Dealing with Scratches and Abrasions on Film 389 DARK-ROOM HINTS 390 Antidotes for Poisons 390 Prevention of Dermatitis 390 Removing Developer Stain from the Hands 390 Removing Developer Splashes from Qothes 391 Cleaning Solution for all Non-Metal Vessels 391 Releasing Jammed Glass Stoppers 391 Disinfecting of Wood and Composition Tanks 392 Saving Cracked or Broken Plates 392 Giving Greater Transparency to Paper Negatives 393 Writing on Negatives 393 DEFECTS IN NEGATIVES 394 Faults in the Gradation of the Negative 394 The Negative is Fogged 395 White Deposit on or in the Film of the Negative 397 Dark or Light Streaks or Blotches on the Negative 398 Spots, Flecks and Linear Markings 399 Less Common Negative Faults 400 PHOTOGRAPHIC CHEMICALS 401 RECOMMENDED FURTHER READING 407 INDEX 408 11 List of Tables I. Time-temperature table for standard developer groups 72 n. Keeping properties and useful capacity of developers 76 m. Equivalent quantities of alkalies 83 IV. Equivalent quantities of crystalline and anhydrous salts 85 V. pH values 89 VI. pH values of chemicals and solutions 90 vn. Lengthening of development time by the addition of potassium bromide 92 vm. Characteristics of developing Agents 102 K. Fahrenheit and Centigrade degrees of temperature 108 X. English, American and metric exact values 1 14 XI. Avoirdupois and metric weight measure equiva- lents 114 XII. British liquid and metric measure equivalents 115 xin.