Sentence:  Each scene is shot straight through , as had been the universal custom , from a camera fixed in a single position , but in the outdoor scenes , especially in the capture and destruction of the outlaws , Porter 's camera position breaks , necessarily , with the camera position standard until <WSD>then</WSD> , which had been , roughly , that of a spectator in a center orchestra seat at a play . 
Meaning of the word marked with <WSD> tags:  at that time