It was silent for some time about the open source firmware hack "Magic Lantern" for the 5dmk2. But very recently there is a lot of activity again on the project; Trammell Hudson released a new patch that allows to record bit-rates up to 76 MBps! WOW!
I've finally got around to test the new firmware hack:
I used a 16GB Lexar Pro 600x and SanDisk Extreme Pro UDMA6 (90mbit/sec), those are state of the art CF cards in terms of speed.
I tested the codec on an ultra contrast situation; A silver-bounceboard. But filming the bounceboard I was not even able to get more then a second recorded on "-10" setting. All though that one second looks better then the original setting, it is not usable if I can not record longer until the buffer fills up.
If my subject is easy for the codec, then I can even record in setting "-15" 68 Mbit/sec for several minutes, but because the codec is not stressed I can not see an advantage over the factory settings.
So my opinion is, until there are faster CF cards on the market this new setting on the firmware hack is not useful. All though I have huge
respect for the achievement, a 4:2:2 color sampling option would bring more advantages.