Stereoscopes no longer popular because they takes so much time to take a photographs
Explanation:
Stereoscopes are the devices with which two pictures of the same objects are taken from two different angles like with the right eye angle and the left eye angle and then are viewed together so that these pictures can be seen which will create impression of depth and solidity of the pictures. But these are no longer used much these days because of the work involved in the way photographs are takes a lot of time and is tiring work.
