32 Photography for the Sportsman Naturalist 



Cameras, broadly speaking, are of two classes : 

 the camera which is held in the hands during the 

 exposure, with which only instantaneous expos- 

 ures or " snap shots " can be made, and which is 

 termed a "hand camera," and the one that must 

 be set upon a tripod in order to be used. 



Of the ordinary form of hand camera, the 

 " press the button " type, I shall not speak, for 

 they are of almost no use to the nature worker. 



There are two types of cameras in this class, 

 however, that are the outcome of the almost con- 

 tinuous experiments of the manufacturers in late 

 years, and which have done more to revolutionize 

 nature photography than any other appliance or 

 appliances, and these, I think, are worthy of a few 

 words. 



They are the " twin lens " and the " reflex " 

 cameras. The twin lens was the first to be 

 placed on the market, and it consisted of a 

 "double-decker" box that was practically two 

 cameras in one. There were two lenses, one 

 above the other, of exactly the same focal length 

 and attached to the same front board so that both 

 could be racked out or in at the same time. The 

 lower lens made the picture, and the upper lens 

 acted as a view finder. At the back of this upper 

 lens was a mirror, placed at such an angle that it 

 reflected the image, thrown upon it by the lens, 

 on to a ground glass which was set in the top 



