Check out Apertus, the Open Source HD Cinema Camera
Ever since Tramm Hudson hacked the 5D firmware, I've been wondering if some enterprising folks could buy a lot of large CMOS sensors wholesale and develop their own camera. After all, the RED camera is essentially a laptop computer (housed in the camera's body) attached to an imaging chip. Apertus is one such open-source cinema project that began in 2006; here's where the project stands today.
Apertus uses an Elphel camera tethered to a Linux laptop and offers a variety of resolution and recording modes (including a RAW format). Battery and viewfinder options are still being worked out. It runs on a custom piece of software known as Elphel Vision, which looks like this:
Yes, that's a live histogram displayed in the lower-right corner. However, for filmmakers looking for a DSLR-like shallow depth-of-field, the sensor is likely the deal-breaker: it's a CMOS bayer-pattern sensor with an optical format of 1/2.5″ (5.70mm x 4.28mm). This puts the camera squarely in the range of a prosumer video camera (in terms of sensor size) instead of HDSLRs and forthcoming cameras like the Panasonic AF100. However, the Apertus's native resolution of 2592×1944 is plenty high (it translates to 5 megapixels). More interestingly, the Apertus uses an external SATA port for connecting to a SATA Hard drive, CF cards, or SSD device.
Some test footage (note that this is with the addition of a 35mm adapter):
Here's some 100fps slo-mo footage:
The idea of an open-source camcorder is certainly an intriguing one -- while Apertus currently has too small a sensor to pique my interest, the fact that it's an open-source project means one could always swap in a larger chip... and the fact that it's licensed under a GPL is terrific. In a sense, the ever-developing project has limitless potential. For more details on Apertus, check out the following link.