A Bird Photographer's Outfit 



103 



the shutter by means of a long thread from a distant point. Neither a thread 

 nor a bulb and tube will work with certainty at long range, and it is impossible 

 to tell whether an automatic shutter has been released or not. 



If this is to be the only camera used, it should be fitted with a fo'cal-plane shutter 

 also, which is an absolute necessity for photographing flying birds, as this requires 

 an exposure of from one four-hundredth to one eight-hundredth of a second, 

 according to the speed at which the bird's wings are moving. More fully ex- 

 posed plates can be obtained at high speed with the focal-plane shutter than 

 with any other, because the lens is always wide open, no time being lost in 

 opening and closing the shutter, and because the adjustable slit in the curtain 

 traverses from top to bottom of the plate, exposing all portions of the plate 

 uniformly. In order to use this camera for tree work, special apparatus is needed 

 for attaching the camera to the trunk or branches. I have a little device con- 

 sisting of a brass base which can be fastened to the tree by an ordinary shawl- 



SHORT-FOCUS, REFLECTING, AND LONG-FOCUS CA.MERAS 



Strap; the camera is then secured to the base by a double ball-and-socket joint, 

 also of brass, one member of which screws into the base and one into the camera, 

 thus enabling the camera to be pointed in any direction. This ball-and-socket 

 joint can also be used conveniently in the tripod top for pointing the camera 

 downward or upward without adjusting the legs. The whole apparatus folds 

 up compactly with the tripod, the shawl-strap serving as a handle. Another 



