The lens is arguably the most important part of a camera when it comes to influencing image quality. This is one of the major reasons why DSLR cameras still produce better photos than smartphone cameras — even when the resolution is identical. Lenses are also very expensive and most photographers spend far more money on lenses than they do on cameras. For that reason, most DSLR manufacturers design new camera models to work with existing lenses. To carry that capability over the world of DIY cameras, Tom Schucker built a Raspberry Pi camera system compatible with Leica M mount lenses.
Leica introduced the M mount way back in 1954 and it is still in use today. In addition to Leica, several other camera manufacturers (Minolta, Konica, Ricoh, and many others) also used the M mount over the years. This means that there are many new and used M mount lenses available, along with lots of photographers that have collections of these lenses. The lenses are compatible with modern Leica cameras, including the M11. But that is a very expensive camera (around $9,000 USD) and is out of reach for most of us. Schucker's Pieca camera lets photographers take advantage of Leica M mount lenses with an affordable and hackable base.
Pieca resembles a cross between vintage Polaroid and Kodak Brownie cameras. It doesn’t have a viewfinder (which would complicate the optics), but rather a large 5” touchscreen. It contains a Raspberry Pi 4 Model B single-board computer and a Raspberry Pi High Quality Camera. That camera utilizes a 12.3 megapixel Sony IMX477 7.9mm image sensor. That camera supports C and CS mount lenses right out of the box, but isn’t directly compatible with Leica M mount lenses.
Most of Schucker's work went into creating an adapter to make M mount lenses work correctly with the Raspberry Pi HQ camera. That was more than just providing a physical mounting interface. Leica designed M mount lenses for 35mm film and then large image sensors on digital cameras, but the Raspberry Pi HQ camera’s sensor is quite small. The necessitated the integration of a focal reducer to bend the light into a smaller area.
Power comes from a Pisugar S Plus battery and charger setup, with an added Microchip ATtiny85 microcontroller to monitor battery voltage for a software battery gauge. The shutter button is a Cherry MX key switch. A USB thumb drive acts as removable storage and a USB GPS dongle provides location metadata for photos. All of those components fit inside of a 3D-printable enclosure. The user interface comes from software developed by eat-sleep-code, which Schucker modified to work well with Pieca.
The result is a DIY digital camera that costs less than $200 to build and that can support the wide range of available Leica M mount lenses. Photo quality will never compare to a Leica M11 (the image sensor is too small, among other reasons), but the use of professional lenses will dramatically improve quality when compared to most DIY cameras.