DEFECTS IN NEGATIVES AND PRINTS 545 



Yellow Stains. 



1. Distinguishing Characteristic. — Yellow stains on portions of print. 



2. Cause. — Yellow stains are a fairly frequent source of difficulty and may be due 

 to a number of causes, among them: (a) exhausted fixing bath which permits develop- 

 ment to proceed, (6) forced development, (c) weak or exhausted developer, {d) hypo 

 carried into the developer, (e) failure to rinse prints between developing and fixing 

 baths, (/) uncleanUness or impurities in development, {g) incomplete washing of the 

 print after fixing, {h) exposure of print to light after development but before fixing 

 has been completed, {i) prolonged exposure of paper to moist salty atmosphere. 



3. Prevention. — -The preventive measure which will be required will suggest 

 itself when the true cause of the yellow stains has been discovered. 



4. Remedy. — Make new print. 



Unevenness 

 Small Black Spots. 



1. Distinguishing Characteristic. — Small black spots, usually circular, on the print. 



2. Cause. — Print made from negative which has unretouched pinholes. 



3. Prevention. — Printing from perfect or retouched negative. 



4. Remedy. — The black spots in the print may be bleached out by applying a small 

 amount of tincture of iodine, applied with a fine brush or sharpened stick of wood, 

 after which the print is washed in hypo. The black spot is changed to a white spot 

 which may be retouched in the usual manner with a spotting brush (see Camera, 

 December, 1937, p. 404). 



Uneven Development. 



1. Distinguishing Characteristic. — Streaks of varying density in the print, some- 

 times accompanied by yellow discoloration. 



2. Cause. — Uneven development. 



3. Prevention. — Immerse print in properly prepared, full-strength developer 

 quickly and thoroughly, agitating it during the first few seconds. The print should 

 be thoroughly immersed in developer solution, it should not be permitted to float on 

 top of the solution, and the tank or tray should be rocked. 



4. Remedy. — ^Local intensification may be used to build up the less dense portions 

 of the negative. 



Uneven Fixing. 



1. Distinguishing Characteristic. — Uneven density in print, which bears no relation 

 to image. 



2. Cause.- — Uneven fixing. More specifically the cause may be due to (a) air 

 bells forming on print (see Air Bells); (6) failure to agitate print sufficiently well in 

 fixing bath; (c) prints sticking together during fixing, so that protected areas do not 

 become fixed. 



3. Prevention. — Immerse print quickly and thoroughly in fixing bath. Agitate 

 print during fixing. 



4. Remedy. — Make new print. 



Bibliography 



Periodicals: 



Crabtree, J. I., and G. E. Matthews: Study of Markings on Motion Picture Film Produced by Drops 

 of Water, Condensed Water Vapor, and Abnormal Drying Conditions, Trans. Soc. Motion Picture 

 Engrs., 7, 29 (1923). 



