Does negative refraction make a perfect lens?
  A discussion of a question, studied earlier by V.Veselago in 1967 and by J. Pendry in 2000, is given. The question is: can a slab of the material with negative refraction make a perfect lens? Pendry's conclusion was: yes, it can. Our conclusion is: no, in practice it cannot, because of the fluctuations of the refraction coefficient of the slab. Resolution ability of linear isoplanatic optical instruments is discussed. 
A.G.Ramm