rpi-camera: Raspberry Pi High Speed Camera. An open-source camera system for experimental measurements. We present an affordable, yet accurate and modular camera system solution developed on Raspberry Pi 4/4 GB platform with Raspberry v2.x and HQ camera modules with 8 and 12.3 megapixels still resolutions, respectively. The system uses freely available Python scripts and libraries for digital image processing and non-contact optical measurements under MIT licenses as a contribution to the open-source initiative. Several investigations were conducted with the present system, which were two-dimensional (2D) digital image correlation (DIC) for the displacement and strain analysis, the kinetic analysis of the photoisomerization of the spiropyran (a model system for a time-dependent chemical reaction yielding molecules with differing color with respect to starting material) with time-lapse photography, lap shear tests with the assistance of high-speed image capturing and contact (wetting) angle measurements with still images and time-lapse photography. These studies show that the camera system, setups and scripts can be confidently integrated into the chemical, physical and mechanical tests.