The invention relates to a dual-field (NF and WF) imaging system comprising an optronic detector (1) and an optical combination of narrow-field focal length FNF having, an optical axis a front lens, a narrow-field entrance pupil situated in the vicinity of the front lens, a real wide-field entrance pupil, that is to say situated upstream of the front lens, an intermediate focal plane (IFP). The optical combination has, on the optical axis, the following refractive groups: a convergent front group G1 of focal length F, where F