CAMERAS 



81 



Simplest of the view finders is the direct-vision type. This consists of a wire frame, 

 more or less the exact size of the film or plate to be used, and a peep sight. Usually 

 the frame is situated at the lens position; the peep sight is usually at the focal plane. 

 The camera is held at eye level; therefore the picture composed in this type of finder 

 tends to be more natural than one composed in a type that must be held at waist 

 level. (Photographers for fashion magazines usually choose a very low point of view 

 to accentuate the vertical lines of the models and their clothes rather than the hori- 

 zontal lines. A reflex type of camera is preferred for this purpose.) 



The frame and the peep sight need not necessarily be located, respectively, at the 

 lens and at the focal plane, but wherever they are located, their relative dimensions 

 with respect to each other and the eye and to their respective locations must be such 

 that the eye will see what the camera lens embraces. These finders generally fail to 

 include the proper view when the camera is very close to the object and should not be 

 relied upon for close-ups. 



Refiecting-type Finders. — Cameras of the simplest types are usually equipped 

 with a finder consisting of a lens, a mirror, and a ground glass upon which the lens 



Peep 

 sighi- 



FiG. 9. — Direct-vision view finder. 



focuses the image. The image is right side iip but is reversed, right to left. The focal 

 length of the finder lens is short enough (about 1 in.) so that a small image is produced 

 and all objects within the range of the camera adjustment will be in focus. There is 

 no relation between the focal lengths of the finder and the camera lenses. 



A reflecting type of finder which is more efficient in its use of the light collected by 

 the lens is commonly known as the "brilliant" type. The lens forms an image, not 

 upon a ground-glass screen, but in a second lens which confines the fight collected into 

 a narrow cone and directs it to the user's eye. At a normal viewing distance of 12 

 in. above the finder, the cone of light is wide enough to include both eyes of the user. 

 It is necessary that the user assume such a position that his eyes intercept the cone of 

 light or he will not see the image of the scene he is to photograph. A hood is usually 

 part of a brilliant finder. It shields the image from extraneous light. 



In still another type of finder (direct-vision optical finder) a strong negative lens 

 forms a virtual image in front of the lens and a weak positive lens projects this virtual 

 image to a comfortable position with respect to the eye, i.e., about 15 ft. away. The 

 image in such an optical finder is erect and not reversed. 



