i8 NATURE AND THE CAMERA 



allowing the plate to remain in it for from one to 

 three minutes. 



PRINTING. In making a negative the prints must, 

 of course, be thought of and the plate made that will 

 best suit the paper one expects to use. Each kind of 

 paper requires a certain quality of negative. Although 

 these qualities cannot very well be expressed in writ- 

 ing, they will soon be discovered. The extremes may 

 be said to be albumen, which requires a strong, dense 

 negative, and velox, which gives the best results when 

 the negative is thin and full of detail. 



For most printing-out papers (papers which show 

 the image while printing) the printing should be 

 done in the shade if the plate is thin, and in strong 

 sunlight when a dense plate is being printed from. 

 Subdued light increases contrast, strong light de- 

 creases it. 



Local printing, which often saves a picture, is 

 accomplished by letting the light strike the plate 

 locally, being careful not to have hard edges. A 

 piece of cardboard with a hole cut in it will enable 

 one to concentrate the light on the parts requiring 

 the most printing. Do not, however, place it too 

 close to the plate. 



A very flat sky is much improved by allowing the 

 light to fall on the paper very gradually (after the 

 printing is finished and the paper removed from 



