A NEW TELEPHOTOGRAPH SYSTEM 551 



number of scanning lines employed. Certain types of pictures such 

 as portraits, small groups, and others of a rather limited information 

 content were transmitted satisfactorily with this early equipment, but 

 transmissions of those pictures containing much greater amounts ol 

 information frequently were regarded as inadequate. 



In formulating specific requirements for the new telephotograph 

 system consideration also was given to the increasing interest in news 

 pictures and to the trend in this country toward improvement of 

 newspaper halftone reproduction. The former public demand for 

 pictures of the occasional catastrophe or outstanding news event is 

 today apparently being supplemented by an interest in the pictorial 

 reporting of even minor news items. These factors are reacting to 

 elevate the standards for acceptable telephotographs to a plane where 

 newspaper halftone reproduction of original and transmitted pictures 

 may soon be comparable in quality and information content. The 

 requirements met by the new telephotograph system are summarized 

 briefly in the following paragraphs. 



Scanning 



Pictures are scanned by reflected light at 100 lines per inch. This 

 permits direct transmission from original subject matter in the majority 

 of cases without recourse to special preparation such as photographic 

 copying. 



Size of Image Field 



A useful image field is provided for scanning and reproducing 

 pictures of various sizes up to and including 11 inches by 17 inches. 

 This area is sufficient to accommodate most sizes of subject matter 

 likely to be encountered in telephotography and is well adapted to 

 transmission of black and white information such as financial state- 

 ments, advertising layouts, and the like. Furthermore, it provides a 

 practical method of varying the information content of received 

 pictures by using original prints of appropriate sizes. This point 

 is illustrated in Figs. 9 and 10, which are reproductions from trans- 

 missions made from prints of the same subject which were respectively 

 43^ by 63/8 inches and 10 by 14}/^ inches. The useful circumference 

 of the picture cylinder employed is 11 inches. In the case of news 

 pictures, which are ordinarily distributed as 8 by 10 inch photographic 

 prints, the remaining one-inch space on the circumference of the cylinder 

 may be utilized for transmitting the caption as part of the picture. 



Speed of Transmission 

 The image field in the new equipment is scanned at 100 lines per 

 inch with a velocity of 20 inches per second, which results in the 



