Atlas Lens Co. has an over-an-hour-long video on the history of anamorphic lenses that is well worth watching.
The presentation was given by co-founder Dan Kanes to students at Art Center College of Design. It goes into detail about the progression from early, difficult-to-use systems to later innovations like Panavision’s lens designs, which solved distortion issues in close-ups.
In the 1950s, Hollywood faced a decline in theater attendance, so studios turned to anamorphic lenses to help create immersive widescreen experiences using standard film strips. Filmmakers turned to a technology originally designed by Henri Chrétien during World War I for tanks.
As anamorphic lenses were expensive and specialized, the industry moved from studios owning their own gear to the rental house model that is still used today.

