1090. Under-Exposure

Under-Exposure. An under-exposed plate, when out of the reversing solution C, after the first development, shows a dark image lacking detail in the shadows. The result is the same as in the case of an ordinary positive from an under-exposed negative.

1091. Over-Exposure

Over-Exposure. An over-exposed plate, when out of the reversing solution C shows a very thin and flat image. The result is the same as in the case of an ordinary positive from an over-exposed negative. The image may be improved as regards contrasts, by successive intensifications with solutions F and G.

1092. Blue Image

Blue Image. When the image shows a dominant blue color it means either that the ray filter has not been correctly placed in position, so that a portion of the light fails to go through it before reaching the sensitive film; or that the dark-room, camera, or plate holder was not perfectly light-tight.

1093. White Light reaching the back of the plate causes a kind of blue violet veil which persists in the shadows of the image. This blue coloration may also occur when the ray filter is placed in front of the lens and does not tightly fit the mount, and also when the ray filter, either placed in front of or behind the lens, is too small to cover the lens tube entirely.

1094. Fog

Fog. When the dark-room light is not perfectly safe, it may cause fog by acting on the sensitive film either directly or through the glass and the layer of colored starch grains. In the first case, a black fog appears, which affects the brilliancy of the image; in the second case, the red light passing through the red-colored starch grains causes a red fog particularly visible in the shadows, but somewhat weakened in the high-lights.

1095. Black Streaks

Black Streaks. When the immersion in the reversing permanganate solution C is not sufficient, some particles of reduced silver may not be dissolved. These parts are darkened when intensification takes place and then appear as irregular black streaks.

1096. Reduction Of The Image When Fixing

Reduction Of The Image When Fixing. When the second development is not sufficient (developer too weak or its action not sufficiently prolonged) the colored image is weak and weakens still more in fixing. The same trouble occurs when the second development is not carried out by full daylight.

1097. Details Eaten Away

Details Eaten Away. When the plate is immersed too long a time in solution E, or when said solution is too highly concentrated, details in high-lights may be eaten away.

1098. Dichroic Fog

Dichroic Fog. When the finished image shows dichroic fog in the high-lights, the plate ought to be treated again in the permanganate solution H and afterwards in the hypo solution I.

1099. Decrease In The Brilliancy Of Colors And General Reddish Tinge

Decrease In The Brilliancy Of Colors And General Reddish Tinge. When final washing is too long (longer than five minutes in running water) the brilliancy of colors is reduced and a reddish discoloration appears all over the high-lights.

1100. Frilling occurs when the outside temperature is too high or when there is too great a difference between the temperature of the solution and that of the washing water. The temperature of the different solutions ought not to exceed 65o F (18o C), and the water should be of about the same temperature. This trouble may be overcome by the use of chrome alum as directed. It will be found of advantage to cool the solutions and the trays before using them.

1101. Black Spots

Black Spots. The manufacture of "Autochrome" plates is extremely delicate, and it is sometimes impossible to get them perfectly free from small black spots. These can be retouched with a fine camel's hair pencil soaked in the permanganate solution C. After such retouching the plate should be rinsed, immersed in the fixing bath, washed, and dried again.

1102. White Spots

White Spots. These can be retouched, as usual, with India ink, graphite, or any other black pigment, diluted in gum arabic. Retouching should be done after varnishing.

1103. Scratches

Scratches. The sensitive film is extremely delicate. For this reason the undue pressure or friction of black cardboard, springs, etc., may cause scratches and even minute ruptures of the varnish pellicle under the sensitive film. Where the film is ruptured green patches will appear.

1104. Stains on the Fingers, caused by the intensifying solution, may be easily removed by soaking fingers alternately in solutions C and I.