The main difference between the FED-2 and its predecessor FED was the combination of the viewfinder and rangefinder, which received a common eyepiece, which allows focusing and framing at the same time. In addition, the standard base of the rangefinder has increased to 67 mm, and the back wall of the die-cast aluminum case has become removable, which greatly simplifies charging. However, despite the wide standard rangefinder base, due to the combination with the viewfinder with 0.75 × magnification, the effective base was still inferior to the main competitors "Kiev" (Contax) and Leica III (50.25 mm versus 58.5 mm.). For the first time for FED, the eyepiece of the sighting device was equipped with diopter adjustment using a lever under the rewind head.