Today, Sony has announced that it is disclosing, without any fees, the basic specifications for its E-mount for interchangeable single lens cameras. The move will allow manufacturers of lenses and mount adaptors to develop, from 01 April, compatible products for its NEX-3, NEX-5 and NEX-VG10 compact cameras and camcorders.

"Users of the Sony's E-mount compatible digital imaging products will now be able to use interchangeable lenses from both Sony and various other manufactures," says Sony. "They will also be able to attach non-Sony lenses to their Sony digital imaging products via a mount adapter."

The basic specifications will be disclosed to manufactures of lenses and mount adaptors following a predefined process of approval and the signing of a license agreement with Sony, says the firm.

Already, Carl Zeiss, Cosina, Sigma and Tamron have pledged to release compatible products. Tamron, for example, says it aims "to offer our customers new solutions and unprecedented photo-shooting enjoyment through the manufacture and sale of E-mount' lenses," while Sigma adds that "the move will spur the further growth and diversification of camera system across the industry, provide photo enthusiasts with a wealth of choice and enrich in their photographic lifestyles."

The decision comes on the heels of a series of announcements released, over the past few days by Olympus and Panasonic, the two companies behind the Micro Four Thirds format of mirrorless cameras.

The format has now won the backing of Schneider-Kreuznach, Carl Zeiss and Komamura - bringing the number of Micro Four Thirds backers to 11 - including Kodak, Fujifilm, Cosina, Leica and Sigma.

Carl Zeiss is expected to produce HD Video lenses for all Micro Four Thirds cameras, "contributing to a vastly expanded product line and enhancing the joys of digital imaging with the Micro Four Thirds System," it says.

The recent additions to the Micro Four Thirds System Standard Group will also bring both Schneider Kreuznach lenses and Horseman accessories to Micro Four Thirds camera users.

While Samsung also has its own range of mirrorless interchangeable single lens cameras, it has yet to officially open up its system to third-parties.

Last week, Nikon has hinted at plans to release its own compact system, leaving Canon the only major manufacturer without known-plans for mirrorless cameras.