The upcoming experiment with camera coverage of federal district courts will be governed by a restrictive set of rules announced Wednesday by a committee of the Judicial Conference. The three-year experiment begins July 18 at 14 district courts around the country.

The Judicial Conference voted last September to launch the pilot project testing the impact of camera access in federal district courts. The Conference ran a similar experiment in the early 1990s with generally positive results. But then the excesses of the O.J. Simpson trial set back the cause for cameras in federal courts for more than a decade. The new experiment comes after prodding by Congress, with an assist from some federal judges who see a need for the courts to tap technology in the interest of educating the public.