Popular in the 1970s and 1980s, but now superseded by digital presentation software, Multi-image (also known as multi-image slide presentations, slide shows or diaporamas) 35mm slide projections onto one or more screens characteristically lent themselves to the wide screen panorama. They could run autonomously with silent synchronization pulses to control projector advance and fades, recorded beside an audio voice-over or music track. Precisely overlapping slides placed in slide mounts with soft-edge density masks would merge seamlessly on the screen to create the panorama. Cutting and dissolving between sequential images generated animation effects in the panorama format.