“I” is for Instamatic, Kodak’s camera for 126 cartridge film
Instamatics arose with the advent of 126 cartridge film. The cartridge made loading and unloading the camera very easy.
The funny thing about Instamatic cameras is that there are so many different kinds.

Some of our Instamatics
The Instamatic 400 – with the flash open and ready to accept the peanut bulb. 1963-1966

The Instamatic 704 took flash cubes. 1965-1969

Instamatics with ‘X’ in their name used the special ‘Magicube’ flash. 1970-1976

This Instamatic (the Instamatic 60) was made for 110 cartridge film. This one has a coupled rangefinder. 1972
Most Instamatics were rather cheaply made in the USA, but the Instamatic 500 was made in Germany with high-quality glass. 1963-1966

Almost all Instamatics were simple view-finder cameras, but the Instamatic Reflex was an SLR. 1968-1974