The action of erecting an inverted image without deviation by a prism is used in
The action of erecting an inverted image without deviation by a prism is used in Slide projector. To erect the inverted image without deviation, A reflecting prism is also used. Theslide projectors use this property of the prism A totally reflecting prism is that which has one of its angle equal to 90,equal to 45 degree here the phenomenon of total internal reflection is used.