This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
II. 77.
Avoided by immersing the dry plate, immediately upon their first appearance, in a solution of powdered alum or chrome alum, or a weak solution of formalin. (See reference.)
Suppressing, or painting out with opaque paint, any part of the negative which it is not desired to have printed. The blocking-out should be done by painting, preferably on the back of the negative. Ready prepared " opaques" are obtainable from photographic dealers, yet the following will be found very satisfactory:
Asphaltum................................ | 1/2 oz. |
Beeswax.................................... | 85 grs. |
Carbon Black............................. | 40 grs. |
Turpentine................................. | 5 ozs. |
(See Paper, Blotting.)
Useful in viewing a landscape to secure an idea of the effect when reduced to monochrome.
An iron printing process. Development effected by water only. Blue-Print Process - Sensitizing Solution - I, 367. Blue Tones on Bromide and Developing Papers - V, 713-715.
(See Copper Sulphate.)
When an image has a double or an indefinite outline it is said to be blurred. May be caused by movement of object or by jarring the camera during exposure; also caused by halation, aberration, or poor focusing of image on ground-glass.
212 degrees Fahr. | |
Alcohol.................................. | 176 degrees Fahr. |
Ether....................................... | .96 degrees Fahr. |
Mercury.................................. | 662 degrees Fahr. |
(See Sodium Borate.)
Care should be exercised in selecting bottles for various chemicals. Acids and ammonia should be kept in glass-stopper bottles and the stoppers rubbed with a little vaseline, which not only renders the bottles air-tight but prevents the stoppers from sticking. Solids should be kept in wide mouth bottles. Chemicals sensitive to light should be kept in amber or non-actinic bottles.
A small bottle which will hold liquids, and from which small quantities of the liquid can be obtained in drops.
To remove PHOTOGRAPHIC SOLUTIONS use hydrochloric acid mixed with an equal quantity of water. GREASE; rinse with benzene, then apply a strong solution of sodium carbonate. VARNISH; rinse with alcohol, I ounce, and ammonia, 1 dram; then ammonia, 1/2 ounce, water, 5 ounces, and follow this with a good wash in water.
 
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