18 



BIRD STUDIES WITH A CAMERA 



accompanying the contact prints from tlieir respec- 

 tive negatives. In each instance the enlargement is 

 about three diameters, and tlie telephoto negative 

 of coiirse furnishes the most satisfactory picture. 



II. Lens Test No. 3. Same subject, distance, plate, and d:ite as Tests Nos. 

 2 and 3. Eiglit-inoli Zeiss Convertible, Series Vll «, N'o. 10, with tele- 

 photo attach ment ; diaphragm F. 8; twenty-oue-inch liellows ; one sec- 

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



When the difficulties of telephotography are consid- 

 ered, however, and tlie ^V^econd 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 photogra])hing 



