DLSR video is great, having ushered in a new ecosystem of tools, workflows, and filmmakers. In the last couple of years, though, the image quality has stagnated while other, video-centric cameras like the Canon C300 or the Blackmagic Cinema Camera have proven superior. However, it turns out that hidden inside the Canon 5D Mark III, firmware-hackering group Magic Lantern has uncovered RAW video recording capability.
The hack is a work-in-progress, and not yet available for public release, but the results so far are pretty impressive. Magic Lantern figured out how to hijack the feed of video running to the camera's live-view monitor, which it then stores as individual DNG files on your memory card. Within these DNG frames are essentially all the detail and dynamic range you would find in the 5D Mark III's photo mode, just downscaled to 1920 pixels wide. Technically, you might say it isn't true RAW, because the images are being processed in order to downscale. But the quality remains intact.
Over at EOSHD, there is a great write-up detailing some of the ins and outs of working with the hack. Of course, it comes with some caveats. Not only will you need super-fast 1000x CF cards with great big storage capacities, but with so much data being written there are risks of overheating the camera.
The fact is, we don't yet know how useful this will actually be in real world shooting scenarios, and thus far, it is only working on the Mark III version of the 5D. But the accomplishment is just very cool nonetheless, and they have only just begun.