332 DRAWING WITH THE EPISCOPE [Cn. X 



DRAWING WITH THE EPISCOPE OR REFLECTING LANTERN 



469. If one has access to a lantern for opaque objects (Chap. 

 VII), diagrams may be made from pictures in books and from suit- 

 able objects without the trouble of making a negative or a lantern 

 slide. The object is put in position in the reflecting lantern and its 

 image thrown upon the drawing surface. It can then be traced 

 as for a lantern-slide image, and the details, shading and lettering 

 added as described for diagrams made from lantern slides or from 

 negatives (464). 



470. Drawing on a horizontal surface by the aid of the opaque 

 lantern. If the apparatus is suitably arranged, the mirror will 

 throw the image downward upon a horizontal surface instead of out 

 horizontally. Then the tracing can be made as for a lantern slide 

 ( 468). There is one difficulty with the reflecting lantern in mak- 

 ing drawings. If the object to be drawn is of some thickness, only 

 a part of it will be in focus at any one time, hence it is not easy to 

 get the parts in true perspective. (For erect images see 514). 



If one makes a small negative with a good objective, the perspec- 

 tive will be good and all the parts will be in focus. 



When this negative is projected upon the drawing surface with an 

 ordinary lantern, all the parts of the image will be in focus. 



If one wishes drawings of flat objects, pictures in books, etc., the 

 opaque lantern answers admirably, but heavy currents are re- 

 quired, and it is not so safe for inexperienced persons as the magic 

 lantern with a small current and a negative or a lantern slide (see 

 further in Ch. VII, 290). 



DRAWING WITH A PHOTOGRAPHIC CAMERA 



471. The drawing of enlargements or reductions of opaque 

 objects with the photographic camera has been much practised. 

 The object is put in a good light and arranged to show the desired 

 aspect, then a photographic camera is directed toward it, and the 

 bellows lengthened or shortened until the picture on the ground- 

 glass focusing screen is of the desired size. Then the plate holder 

 with a clear glass or a focusing screen of clear glass is used and over 



