Overview
The function of a bellows device in general:
1. Stepless extension = distance between sensor/film plane and lens (= image distance); thus format-filling photographing of smaller objects possible.
2. With the Schneider Kreuznach lens Apo Digitar 4.5/90 step-less adjustment from infinity to 1:1 with 35mm camera.
3. Telephoto lenses focus much closer than their near focusing range (without bellows); therefore tele-perspective in the close-up range and above all long working distance (no disturbance of the object, space for additional lighting).
4. With standard- and especially wide-angle lenses (from the camera range) enlarged images = macro shooting; over 1:1
5. On the tripod: a separate focusing rack (CASTEL series) is used to focus without changing the bellows extension (= frame size) or the tripod; i.e. the zone of[nbsp]sharpness can be adjusted, while the magnification remains constant.