An imaging apparatus is provided, comprising a first lens, a Wien filter having a first opening and a second opening, and further comprising a 2*m-pole element, m≧2, and a second lens, wherein said first lens is disposed upstream said first opening of the Wien filter and said second lens is disposed downstream said second opening of the Wien filter, and an intermediate image plane of the first lens is located between said first opening and said first lens and an intermediate object plane of the second lens is located between said second opening and said second lens, and wherein said Wien filter is adapted for dispersion-free imaging of a stigmatic image formed in said intermediate image plane of said first lens into a stigmatic image formed in said intermediate object plane of said second lens.