13x18 negative insert (septum) with cut corners

Film Holder Inserts for Large Format Cameras

Film holder inserts are essential whenever modern sheet film is used in older large format cameras equipped with holders originally designed for glass plates.

Their primary function is to provide the flexible film with sufficient rigidity to keep it perfectly flat during exposure. At the same time, the insert ensures precise positioning of the film inside the holder so that its plane coincides with the camera’s ground glass plane.

Differences between holder systems

Different types of large format holders require different insert designs. For example, Mentor camera holders require inserts with cut corners, whereas Globica holders allow the use of inserts with a folded edge running along their entire length. In the Mentor system, standard inserts may sit at an incorrect angle, preventing proper alignment of the focal plane.

Inserts for Mentor cameras

The inserts offered here are specifically designed for Mentor camera holders. Their geometry, including the characteristic cut corners, follows the original design used in this system, ensuring correct film positioning and accurate alignment with the focusing plane of the camera.

This practical solution allows modern sheet film to be used seamlessly in classic Mentor holders without compromising precision or requiring technical workarounds.