FISH PHOTOGRAPHIC EXCURSIONS 171 



a diving-suit, and conceal oneself in the water, as the 

 Keartons conceal themselves on land ; but even then 

 the scope of sub -aquatic photography would be greatly 

 limited by the question of light. 



As the nearest approach to fish photography in 

 natural environments, I have referred, in the intro- 

 duction, to the use of a specially constructed pond. 



Fish photography can also be undertaken with the 

 camera above the water ; but as the object of such 

 work is essentially to see fish as they appear to each 

 other, this bird's-eye view of fishes is only interesting in 

 the case of those which live near or on the bottom. 



The difficulty in this form of photography lies in 

 the fact that the light reflected by the surface of the 

 water obscures the fish and fogs the plate. Every angler 

 will have noticed that even in a clear, smooth-running 

 stream, very little can be seen below the surface, except 

 where a tree overhangs the banks. The tree cuts off 

 the light from above and the weeds, stones, and fish 

 beneath the water become visible. In the same manner 

 every pebble on the bottom under a bridge can be 

 counted. 



Under certain conditions, even when the light from 

 above is not cut off, the observer is able to concentrate 

 his attention upon the fish and ignore the light reflected 

 from the surface. The camera cannot do this, and 

 the greater amount of light reflected from the surface 

 fogs the plate before the lesser amount of light re- 

 flected from the body of the fish can make any impres- 



