Recording to CF and SD at the same time for 5.7k 24fps?

[dannyzuko]

I've just watched this video

and I quote "This is the first test video with my new old Canon EOS 5D Mark III. I am blown away by Danne's video modes, especially this 5.7K anamorphic mode which uses the full sensor width. This makes the footage look very cinematic!

With this mode I got 1920x2332(*) (unsqueezed to 5760x2332) @ 23.976fps and 12bit lossless. And the best: continuous recording!!! This is possible because of the latest SD overclocking and card spanning features. So the CF card writes about 70MB/s and the SD about 50MB/s at the same time.

MLVApp is able to merge the two files (MLV+M00) from the two cards. The entire video was processed and color corrected to ProRes4444 with MLVApp only at original resolution. The final cut was upscaled to 8K for youtube using ffmpeg."

I've just picked up the 5d 3, can anyone help me do this dual card writing?

[Grognard]

You just have to enable card spanning in raw options.
But for 5.7k anamorphic, card spanning is not
necessary except if the scene is too bright or overexposed.

[masc]

That is my video and first 5.7K test in the old days. I still use card spanning for this mode, because it works just fantastic and super stable for this amount of data. Here you find my settings: