120 to 124 Film Adapter

thingiverse

This adapter enables users to load 120 film spools into cameras designed for 124 film, such as old Kodak Brownies, which were originally intended to use rollfilm format 124. The 124 film was one inch wider than 120 and produced negatives measuring 3.25" x 4.25". By utilizing this adapter, the image is cropped vertically into a 'panoramic' 2.25" x 4.25" (approximately 6x11 cm) format. Remade from https://www.thingiverse.com/thing:3787976 but re-implemented in OpenSCAD, with some dimensional tweaks for a better fit and a redesigned drive blade on the 120 end that can accommodate slot-type spool ends, this adapter allows users to convert their cameras for use with 120 film. Four adapters are required, along with an empty 120 spool as a takeup reel. If the camera still contains a 124 spool, it can be used in emergency situations but requires careful handling to avoid exposing the film to light during transfer into the developing tank. The frame number window on 124 cameras is outside the 120 film area, necessitating coverage with lightproof tape and experimentation to determine the optimal amount of film advancement per frame. To achieve successful results, follow these steps: - Align the arrows on the backing paper with the left edge of the frame (refer to the included photo), close the camera, and wind 8 turns to reach frame one. - Wind approximately 3 turns per frame, gradually decreasing to 2.5 turns by the final frame. The OpenSCAD source code used to generate the STL file is provided, allowing users to adapt this design for various early-20th-century rollfilm formats. Included are photos shot on a Kodak Folding Brownie No.3 using this adapter, offering insight into expected results. For cameras equipped with ground-glass viewfinders 'cubes,' users can attach https://www.thingiverse.com/thing:4548712 to provide an approximate indication of the area 120 film will capture.