An electronic imaging device (27) includes an optical objective (28) for collecting optical radiation from an object, the objective having an optical axis, and an image sensor (24), including a matrix of optical detectors arranged in a plane that is substantially non-perpendicular to the optical axis, the image sensor having a lateral dimension in the plane. A turning mirror (38) has an optical surface that is positioned so as to reflect the radiation collected by the objective in order to form a focused image in the plane of the image sensor, while a maximum distance from the optical surface to the plane of the image sensor is substantially less than the lateral dimension of the image sensor.