FLIGHT. Ill 



wards or from the camera and not across the plane 

 of focus ; they must still be at a considerable dis- 

 tance, being represented to a scale not greater 

 than l/100th of life size. Auks, and other birds 

 whose wings beat rapidly, may be attempted at a 

 distance, as may near studies of birds in moderately 

 rapid action, etc. 



1 /500th part of a second. About this speed we 

 may attempt near studies of birds flying leisurely 

 with slowly beating wings, as well as chicks and 

 small birds represented to a large scale while in 

 rapid motion, and near studies generally of birds 

 in energetic action (but regarding the latter see 

 below). 



l/900th part of a second. Near studies of birds 

 flying across the field of view and in rapid flight 

 generally, and pictures of individual auks and the 

 like will require about this exposure. 



l/1200th part of a second. This may be taken as 

 the highest speed at which ordinary focal-plane 

 shutters work, and it is not often that the 

 light will permit of much greater brevity in the 

 exposure. We may therefore say that this is 

 the speed to be allotted to our most trying 

 subjects near studies of birds with rapid wing- 

 beat, and to the closest studies of flight in 

 general. But even when working at this speed 

 we have known a bird's wings to be represented 



