80 PHOTOGRAPHY FOR BIRD-LOVERS. 



as it at first appears. One has to focus for an 

 imaginary object whose position has to be guessed, 

 and when working at close- quarters a very slight 

 mis judgment will throw part of the bird out of 

 the plane of sharp definition. I usually put a 

 cap over the eggs, making it in size and position 

 tally as nearly as possible with the brooding bird, 

 and by focussing carefully for that am seldom 

 disappointed. For small birds a visiting card is 

 useful in the same way : any printed matter is an 

 excellent guide for critical focussing. In a poor 

 light one cannot hope to stop-down sufficiently 

 to get both the near and far sides of a large bird 

 at close quarters sharply defined, but if one makes 

 sure that the definition of the nearest parts is 

 critical, a slight diffusion in others will hardly 

 be noticed. Thus eggs are not an ideal guide 

 for the focus, but if they are employed, the near 

 ones rather than the complete clutch should be 

 focussed. 



A Comfortable Position Necessary. 



All this, of course, is done after your assistant 

 has fastened you up. Before he leaves, however, 

 there is another matter to be attended to your 

 own position. If there is a choice it must be made 

 with some care and forethought, for once you are 

 alone there is to be no further movement of any kind 

 until after the bird's return, perhaps many hours 



