I have a Yongnuo RF-603 II which I used to trigger movie record on my Canon T2i. However, after getting the correct cable and trying it on my Canon 5D MK III, it will remotely take a picture in movie mode with a full press, but I can't get it to trigger movie record.
I read that in the ML Menu under "Movie" the option "Movie Rec Key" can be changed for recording with half shutter. The problem, is that I don't have that under the "Movie" option.
So, am I able to trigger movie record remotely on the 5D MK III as I did on the T2i 550D, if so, how?