A310
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical
Flight Crew Overcame Equipment Problem; General Declared Emergency
Aircraft
In level flight cabin pressure regulator #2 faulted.  #1 regulator did not control cabin altitude and it rapidly climbed through 10;000 feet.  Oxygen masks were donned; jumpseater awakened and told to put oxygen mask on; and crew began ECAM procedures.  Cabin pressure control regained using manual control.  Descent begun to 10;000 feet and emergency finally declared with Center.  Once below 10;000 feet cabin altitude normal operations resumed and continued to destination.  Excellent performance by the First Officer.
[Narrative had no additional information].
A310 flight crew reported loss of cabin pressure. An emergency was declared and control of pressurization system was regained using manual backup.