 Some 2001 cameras were modified to take the new tubes, but it was a difficult retrofit procedure, because of the complexity of the additional circuitry.As supplied by EMI, the 2001 and the later 2001/1, did not have any form of ACT (anti-comet tail) or HOP (highlight overload protection).This is why its performance was poor, in this respect, when compared with the next generation of cameras supplied in the 1970s.