ED (Extended Definition) Beta was introduced in 1988 and was the last variation of the Betamax format that Sony created for the consumer market (the Betacam family of formats for professional use went on to have much greater success). It was announced shortly after JVC ‘s rival S-VHS format.
ED Beta offered 500 lines of resolution (compared to S-VHS and LaserDisc‘s 420 lines) by using special metal formulation tape and some tape transport improvements. Because of its special formulation, ED-Metal tape was expensive, as were the machines.
Two ED Beta decks and a camcorder were produced for the US market, but Betamax had already lost the format war to VHS and ED Beta was discontinued in the US market after just a couple of years. It’s not clear when it was discontinued in Japan, where Betamax machines were still produced until 2002.