18 



BIRD STUDIES WITH A CAMERA 



accompanying the contact prints from their respec- 

 tive negatives. In each instance the enlargement is 

 about three diameters, and the telephoto negative 

 of course furnishes the most satisfactory picture. 



6. Lens Test No. 3. Same subject, distance, plate, and date as Tests Nos. 

 2 and 3. Eight-inch Zeiss Convertible, Series VII o, No. 10, with tele- 

 photo attachment ; diaphragm F. 8 ; twenty-oue-inch bellows ; one sec- 

 ond (Va second was later found to be full time). 



When the difficulties of telephotography are consid- 

 ered, however, and the ^V secon( ^ exposure of the 

 fourteen-inch lens, which permits of hand work, is 

 compared with the one second of the telephoto, we 

 believe that for general work in photographing 



