Blaž Semprimožnik's OKTO35 Is a 3D-Printed Analog Movie Camera and Scanner for 35mm Film Cartridges

Electronics engineer Blaž Semprimožnik has designed an impressive 3D-printed movie camera designed for use with 35mm analog film — positioning it as a low-cost way to both shoot and scan 35mm films.

"A couple of years ago I have been occasionally shooting 35mm films with point & shoot still cameras while also having the desire to shoot motion picture films," Semprimožnik recalls. "Upon reviewing my options, the best way would be to do it with Super8 film, but after financial considerations I concluded that it would be very costly in the long run since shooting just one standard 50ft cartridge wouldn’t be enough for me. Purchasing, developing, and digitalizing costs for just one would be over €100 [around $110]!"

Looking around for a better solution, Semprimožnik decided to start from scratch: designing, printing, and building a functional analog movie camera which could use low-cost 35mm film cartridges — the type normally associated with amateur-level still film cameras. "These are cheaper [than Super8]," the engineer explains, "and are widely available in much larger quantities and type varieties — B&W, color, reversal, UV, IR, special kinds, etc."

The result is the OKTO35, a Geneva-mechanism camera using 3D-printed parts and a DC motor. Other 3D-printed parts offer a guide plane, take-up drum, a motorized C-mount shifter which allows film track exposure to be selected using a built-in solenoid light shutter, and a housing with support for interchangeable lenses.

The electronics, meanwhile, are driven by an STMicro STM32F1 microcontroller with motor drivers, stepper driver, a power management system, and a connector for external sensors such as a light meter — plus a charging circuit for an internal lithium-polymer battery.

"[I programmed] a user-friendly GUI [Graphical User Interface] with simple menu system navigation using a joystick button [and] four different modes of operation: Movie, Photo, Time-Lapse, Scanner, and a system that gathers and processes all data and displays it to the user such as measured exposure values, remaining recording time, current/saved settings, etc.," Semprimožnik explains.

"Nearing the end of coding, many other useful features were added like a timer, recording button modes, and a visual/audible warning system. Programming was done in C language in the STM32 IDE environment."

The OKTO35 is able to shoot just over a minute of footage per 36-exposure 35mm film cartridge at 18 frames per second, meaning three are required to match a single 50-foot Super8 cartridge — a reduction in cost per 10-minute recording of 85 per cent for black and white and 70 per cent for color footage.

Once shot, the recorded footage can be scanned by mating it to a digital camera for lens-t-lens image transfer. "Usage of a smartphone camera with a wireless connection method will be possible in the next camera version MK III," Semprimožnik promises.

More information on the project is available on Semprimožnik's website.