DSLRs Shoot Video With New Patent [Digital Cameras]

The one feature point-and-shoots still have over DSLRs is the ability to shoot video clips. DSLRs are optimized in the other direction--the mirror setup, specialized auto-focus systems, etc. Hiroshi Terada's patent for a movie mode on DSLRs has one big innovation--a semi-transparent mirror--and then pulls a PS2-on-PS3 emulation trick, cramming in the components necessary to shoot solid video alongside the DSLR's regular components.

In order to shoot at 30FPS, Photography Bay notes that a DSLR's mirror would have jump up and down at least three times faster than Canon's EOS-1D Mark III. Terada's semi-transparent mirror doesn't move, but lets 70 percent of the light through to the image sensor, enough for video. The reflected 30 percent takes care of your continuous phase-detection autofocus.

The patent actually uses two different autofocus systems--one for still image shooting, and then another for clips, which has a wider AF threshold (DSLRs tend to have a very narrow one) and a slower, smoother AF speed (vs. the light speed you want for still images). A cropping function would take care of field of view changes that happen during AF shifts.

After Live View, this was the only place left to go--the question is when we'll see these first Zapruder-capable DSLRs, though the next generation doesn't sound like an unreasonable time frame. [USPTO via Photography]
-------------------------