A simple focal-plane shutter tester using BPW34 photodiodes, a bright flashlight, and a sound card

The author shares their experience in building a budget-friendly tester to check the functionality of camera shutters. The device allows users to evaluate shutter speed uniformity and exposure quality without needing to visit professional service centers. The design is based on three BPW34 photodiodes connected to a computer sound card, a bright flashlight as a light source, and a 3D-printed housing. The sensors are arranged in a line along the frame window, enabling detailed analysis of the shutter curtain movement. This solution allows hobbyists and photographers to perform diagnostics and adjustments at home. The author provides all necessary schematics and STL files for printing the housing, making the project accessible for replication. It is a practical solution for those looking to save on professional maintenance and gain a better understanding of their camera's mechanics.