Newman and Guardia had produced a distinctive range of hand, plate cameras and rollfilm cameras with, for their time, innovative features and made to a very high standard. The death of Julio Guardia in 1906 and, more critically, the departure of Arthur S. Newman from the firm in 1908 affected the development of more modern cameras so that by the 1928 the BJPA suggested that N & G 'lay themselves open to the charge of lack of enterprise'.

The New Sibyl Excelsior was designed to refute that charge: 'this very conservatism is, however, a great safeguard to the purchaser, who can rest assured that any new model that may be offered is definitely an improvement and not an experiment'. The Excelsior 'stands out pre-eminent amongst de-luxe roll-film cameras'. It offered the well known lazy tongue arrangement, rising and cross movements with a coupled viewfinder. The most important innovation was a new accurate shutter which was guaranteed to with 10 per cent of the marked speeds from 2 to 50 second. The camera also featured a novel split opening back with automatically lifting spool chambers to load rollfilm. It sold for £36 10s with the Ross lens.