Enlarging 
TABLE FOR ENLARGING AND REDUCING.— 
A232 ao a 
B. 3—1% 4-11/3 5—1% 7—11/6 8—11/7 9—-1% 
A. 9 10 11 12 
B. 10—11/9 11—11/10 12—11/11 13—11/12 
To find the number of linear times of enlargement or reduc- 
tion, divide the longer side of the enlargement by the longer 
side of the negative. Then find this number in the top row A, ~ 
and multiply the lens focus by the numbers in the lower row 
B. The greater distance is that between the lens and sensitive 
paper, and the lesser that between the lens and negative. 
Example: To enlarge 5x 4to 20x 16. As 20+5=—4, if 
a 6-inch lens be used, the distances will be respectively 
6X 5=—=30and6 X 14% =—7VYin. For reducing, the relative 
positions of the sensitive surface and negative or copy are 
reversed, thus to reduce a 20 x 16 four times with a 6-inch 
lens, the latter will be 30 inches from the subject and 7% 
inches from the plate. 
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