112 



C. A. Steinheil Sohne, Miinclien. 



Universal shutter 



for instantaneous and time exposure, made of metal throughout, encased 

 in brass or aluminium and fitted with steel mechanism; simple and 

 quick manipulation, adjustable rapidity, precise action without shock. 



Fig. 22. 



The shutter opens and closes from the center. The most efficient part of 

 the objective is thus made to act throughout the exposure. It is fitted with 

 pneumatic releasing mechanism The shutter is designed for being placed partly 

 before and partly between the lenses. It is made in 5 sizes up to 52 milli- 

 meter aperture and also in the form of stereoscopic shutters with two identical 

 apertures placed 85 millimeter apart. 



